Summary of Recent Mexico City Workshop on NEO Global Planning

More on the recent workshop in Mexico City on developing a global information and warning network on NEOs. From the Secure World Foundation news release, an MSNBC/space.com article, and an NPR radio report.

A group of international experts has outlined steps to establish a global detection and warning network to deal with possible asteroid threats to Earth.

An interdisciplinary group, including asteroid tracking specialists, space scientists, former astronauts, United Nations authorities, as well as disaster management, risk psychology and warning communication experts gathered to take part in a workshop held January 18-20 in Mexico City.

The workshop was organized by Secure World Foundation in coordination with the Association of Space Explorers and the Regional Centre for Space Science and Technology Education in Latin America and the Caribbean (CRECTEALC). The meeting was hosted by the Mexican Ministry of Foreign Affairs.

“This workshop provided a major step forward in our thinking about the needed components of an information, analysis, and warning network for asteroids. The workshop findings should go a long way toward providing the basis for such a network,” said Dr. Ray A. Williamson, Executive Director of Secure World Foundation.

Substantial progress“The report of this workshop will be a very useful input for the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) as it continues with its three-year work plan on drafting international procedures for handling the threat posed by the possible impact to Earth by an asteroid,” said Dr. Sergio Camacho, Secretary General of CRECTEALC. He is a former Director of the United Nations Office for Outer Space Affairs, a post that he held from 2002 to 2007.

“The Association of Space Explorers (ASE), representing the international corps of astronauts and cosmonauts, recognized the substantial progress made at the Mexico City workshop,” said Tom Jones, former NASA shuttle astronaut and current Chair of the ASE Committee on Near-Earth Objects.

“The discussions in Mexico City advanced our understanding of how the global community can better communicate detection and warning information about near-Earth objects (NEOs),” Jones said. “The information-sharing effort is an essential first step in dealing with the global hazard posed by asteroids and comets. The ASE looks forward to spreading the results of the recent workshop and urges future work within the U.N. and by the world’s space agencies to develop the capacity to deflect a NEO headed for Earth, a fundamental mission for our space technology.”

Series of scenarios

Meeting participants worked through a series of scenarios - hypothetical situations designed to highlight the challenges and problems that a future Information Analysis and Warning Network (IAWN) providing global warning and technical analysis would encounter in dealing with an Earth-threatening asteroid.

“For the first time an international group of experts, many who would be the ones doing the actual analysis of an asteroid impact threat, came together to work through the challenges which will be faced by the international community in deciding how to respond to such an event,” said Apollo astronaut, Russell Schweickart, former chair of the ASE-NEO Committee.

“The participants grappled with scenarios ranging from a small impact, where evacuation of the impact zone is the most likely response, up to a large asteroid, where only an immediate decision to initiate a deflection campaign would prevent the disaster,” Schweickart said. “The recommendations from this exercise will be integrated into the work of UN COPUOS where the nations of the world are discussing how to prevent these devastating, though infrequent, events.”

United Nations Action Team-14

IAWN is one of three entities being considered to deal with the NEO impact problem, which were outlined by an Association of Space Explorers report -- Asteroid Threats: A Call for Global Response -- issued in 2008.

That ASE report was sent to the United Nations Action Team-14, a group within the UN COPUOS Scientific and Technical Subcommittee established in 2001 for the purposes of addressing the asteroid impact threat.

Along with IAWN, the Association of Space Explorers report also recommended setting up:
-- A Mission Planning and Operations Group (MPOG) to plan, organize, and conduct any necessary missions to threatening asteroids.
-- A Mission Authorization and Oversight Group (MAOG) to provide decision making.
Attendees of the just-held Mexico City gathering specifically focused on IAWN, although future meetings are intended to discuss the other two entities.

Need for a coordinated, global response

The IAWN workshop was held as a next step to build on the conclusions of the ASE report after a recommendation by Action Team-14 at their meeting in June 2009.

The recommendations from the just-held Mexico City workshop will be briefed at the meeting of UN COPOUS Scientific and Technical Subcommittee next month and submitted to Action Team-14 for consideration.

“We are fully aware that there is a lot of resistance to creating new bureaucracies and massive new institutions,” said SWF Technical Advisor Brian Weeden. “So the objective of the workshop and future discussion is not to create a new United Nations function or entity, but to try and use existing capabilities already being provided by States or institutions and adding other necessary capability. There needs to be a coordinated, global response to asteroid threats, and we are working to find the most efficient and effective way of doing just that,” he said.

Link: Secure World Foundation News Release 

International experts converged on Mexico City this month to discuss the best way to establish a global detection and warning network to monitor potential asteroid threats to all life on Earth.

The three-day workshop called together asteroid tracking specialists, space scientists, former astronauts and United Nations authorities, along with disaster management, risk psychology and warning communication experts.

"This workshop provided a major step forward in our thinking about the needed components of an information, analysis, and warning network for asteroids," said Ray Williamson, executive director of Secure World Foundation (SWF) in Superior, Colo., which organized the event.

The meeting ended Jan. 20 and was also coordinated by the Association of Space Explorers and the Regional Centre for Space Science and Technology Education in Latin America and the Caribbean (CRECTEALC).

It ended just after a small meteorite crashed into a doctor's office in a small Virginia town, and just days ahead of the release of National Academy of Sciences report that found the United States is not doing enough to protect Earth from the danger posed by near-Earth asteroids and comets. The Mexican Ministry of Foreign Affairs hosted the workshop.

Gauging the threat 

Sergio Camacho, secretary general of CRECTEALC and a former director of the United Nations Office for Outer Space Affairs, said the workshop's report will be a vital resource to the U.N. science and technical panel supporting the Committee on the Peaceful Uses of Outer Space.

The committee is engaged in a three-year work plan on drafting international procedures for handling the threat posed by the possible impact to Earth by an asteroid.

Likewise, the Association of Space Explorers (ASE), representing the international corps of astronauts and cosmonauts, recognized the substantial progress made at the Mexico City workshop.

"The discussions in Mexico City advanced our understanding of how the global community can better communicate detection and warning information about near-Earth objects (NEOs)," said planetary scientist Tom Jones, former NASA shuttle astronaut and current Chair of the ASE Committee on Near-Earth Objects.

"The information-sharing effort is an essential first step in dealing with the global hazard posed by asteroids and comets," he added. "The ASE looks forward to spreading the results of the recent workshop and urges future work within the U.N. and by the world's space agencies to develop the capacity to deflect a NEO headed for Earth, a fundamental mission for our space technology."

Serious scenarios  

Participants examined several hypothetical, but gravely serious, scenarios of asteroids threatening to impact Earth. They highlighted challenges a future Information Analysis and Warning Network (IAWN) would encounter.

"For the first time, an international group of experts, many who would be the ones doing the actual analysis of an asteroid impact threat, came together to work through the challenges which will be faced by the international community in deciding how to respond to such an event," said Apollo astronaut, Russell Schweickart, a former chair of the ASE-NEO Committee.

"The participants grappled with scenarios ranging from a small impact, where evacuation of the impact zone is the most likely response, up to a large asteroid, where only an immediate decision to initiate a deflection campaign would prevent the disaster," Schweickart said. "The recommendations from this exercise will be integrated into the work of UN COPUOS where the nations of the world are discussing how to prevent these devastating, though infrequent, events."

Asteroid action team 

IAWN represents just one of three entities being considered to deal with the NEO impact problem, outlined in a 2008 Association of Space Explorers report: Asteroid Threats: A Call for Global Response.

That ASE report was sent to the United Nations Action Team-14, a group within the UN COPUOS Scientific and Technical Subcommittee, established in 2001 to address the asteroid impact threat.

Along with IAWN, the Association of Space Explorers report also recommended setting up:

• A Mission Planning and Operations Group to plan, organize, and conduct any necessary missions to threatening asteroids. A Mission Authorization and Oversight Group to provide decision making.
• Attendees of the just-held Mexico City gathering specifically focused on IAWN, although future meetings will discuss the other two entities.

Coordinated response 

The IAWN workshop built on the conclusions of the ASE report following a recommendation by Action Team-14 at their meeting in June 2009.

Link: MSNBC/space.com article 

Link: NPR story report ("Could An Asteroid Slam Earth Without Warning?")

NASA Administrator Bolden: Recent Comments on NEOs

From spacepolitics.com...

While the rumors, speculation, and debate about NASA’s future direction has exploded in the last few days, NASA administrator Charles Bolden has been out of the country, attending the Ilan Ramon International Space Conference in Israel and holding other meetings there. He did speak with the press there and provided some interesting comments about the future direction of the agency in a 10-minute video provided by Arutz Sheva.

Bolden also paid some attention to the issue of near Earth objects, something that got recent attention with the release of an National Research Council report on NEO surveys and mitigation. “One of my jobs as the NASA administrator—I didn’t realize it when I took the job—is to work in coordination with the Secretary of Defense for protection of the planet, and it means trying to locate and identify things that threaten the planet, be they asteroids or big rocks or what,” he said. Bolden said that NASA has not done a “very good job” looking for NEOs. The impact last summer of an object with Jupiter, witnessed by Hubble among other telescopes, got a lot of attention in NASA and the White House, he said. “That got everybody’s attention, up to President Obama,” Bolden said. “I think you will see us devote a little bit more time—I don’t know how, I can’t state definitively right now how much more money, how much more time, or anything, but you’re going to see one of the things that we do is devote more time and energy to understanding near Earth objects and things that threaten the planet from outside.”

Link: Spacepolitics.com post

Russia Today )RT) Segment on Russian NEO Activities

Link: YouTube Video ("Armageddon tomorrow: What if Asteroid hits Earth?")

YouTube Video: "Avoiding Armageddon: Diverting Asteroids Nuclear Explosives"

Link: YouTube Video ("Avoiding Armageddon: Diverting Asteroids Nuclear Explosives")

Professor Michael A'Hearn Video on Recent NRC Report

From Physorg.com:

Defending Planet Earth from Asteroid and Comet Strikes (w/ Video)
January 25, 2010

University of Maryland Astronomy Professor Michael A'Hearn, leader of NASA's Deep Impact and EPOXI comet missions is vice-chair of a new report from the National Academy of Sciences on detecting and protecting Earth from collisions with comets and asteroids. In the report, "Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies," the panel says NASA cannot meet a Congressional requirement to find 90 percent of Earth-threatening asteroids 155 yards in diameter or larger, unless money is appropriated for the task.

Link: Physorg.com site

Link: YouTube Video (A'Hearn: Protecting Earth - the Challenges)

Link: YouTube Video (A'Hearn: Protecting Earth: What We Need To Do Next)

Link: YouTube Video (A'Hearn: Protecting Earth: Four Recommendations)

JPL Article on Wise Observatory Spotting First NEO

The red dot at the center of this image is the first near-Earth asteroid discovered by NASA's Wide-Field Infrared Survey Explorer, or WISE -- an all-sky mapping infrared mission designed to see all sorts of cosmic objects. Near-Earth objects are asteroids and comets with orbits that come close to Earth's path around the sun. This particular asteroid, called 2010 AB78, is roughly one kilometer (0.6 miles) in diameter, and is currently about 158 million kilometers (98 million miles) away from Earth. Its elliptical-shaped orbit takes it out beyond Mars and back in about as close to the sun as Earth. Because the asteroid's orbit is tilted relative to the plane of our solar system, astronomers do not think it poses a hazard to our planet. As with all near-Earth objects, 2010 AB78 will continue to be monitored. The image shows three infrared wavelengths, with red representing the longest wavelength of 12 microns, and green and blue showing 4.6- and 3.4-micron light, respectively. The asteroid appears redder than the rest of the background stars because it is cooler and emits most of its light at longer infrared wavelengths. In visible light, this space rock is very faint and difficult to see. WISE, which began its all-sky survey on Jan. 14, 2010, is expected to find about one hundred thousand previously undiscovered asteroids in the Main Belt between Mars and Jupiter, and hundreds of new near-Earth asteroids. It will also spot millions of new stars and galaxies. Image credit: NASA/JPL-Caltech/UCLA

From the article...

NASA's Wide-field Infrared Survey Explorer, or WISE, has spotted its first never-before-seen near-Earth asteroid, the first of hundreds it is expected to find during its mission to map the whole sky in infrared light. There is no danger of the newly discovered asteroid hitting Earth.

The near-Earth object, designated 2010 AB78, was discovered by WISE Jan. 12. The mission's sophisticated software picked out the moving object against a background of stationary stars. As WISE circled Earth, scanning the sky above, it observed the asteroid several times during a period of one-and-a-half days before the object moved beyond its view. Researchers then used the University of Hawaii's 2.2-meter (88-inch) visible-light telescope near the summit of Mauna Kea to follow up and confirm the discovery.

The asteroid is currently about 158 million kilometers (98 million miles) from Earth. It is estimated to be roughly 1 kilometer (0.6 miles) in diameter and circles the sun in an elliptical orbit tilted to the plane of our solar system. The object comes as close to the sun as Earth, but because of its tilted orbit, it will not pass very close to Earth for many centuries. This asteroid does not pose any foreseeable impact threat to Earth, but scientists will continue to monitor it.

Near-Earth objects are asteroids and comets with orbits that pass relatively close to Earth's path around the sun. In extremely rare cases of an impact, the objects may cause damage to Earth's surface. An asteroid about 10 kilometers (6 miles) wide is thought to have plunged into our planet 65 million years ago, triggering a global disaster and killing off the dinosaurs.

Additional asteroid and comet detections will continue to come from WISE. The observations will be automatically sent to the clearinghouse for solar system bodies, the Minor Planet Center in Cambridge, Mass., for comparison against the known catalog of solar system objects. A community of professional and amateur astronomers will provide follow-up observations, establishing firm orbits for the previously unseen objects.

"This is just the beginning," said Ned Wright, the mission's principal investigator from UCLA. "We've got a fire hose of data pouring down from space."

On Jan. 14, the WISE mission began its official survey of the entire sky in infrared light, one month after it rocketed into a polar orbit around Earth from Vandenberg Air Force Base in California. By casting a wide net, the mission will catch all sorts of cosmic objects, from asteroids in our own solar system to galaxies billions of light-years away. Its data will serve as a cosmic treasure map, pointing astronomers and telescopes, such as NASA's Spitzer Space Telescope and the upcoming James Webb Space Telescope, to the most interesting finds.

WISE is expected to find about 100,000 previously unknown asteroids in our main asteroid belt, a rocky ring of debris between the orbits of Mars and Jupiter. It will also spot hundreds of previously unseen near-Earth objects.

By observing infrared light, WISE will reveal the darkest members of the near-Earth object population -- those that don't reflect much visible light. The mission will contribute important information about asteroid and comet sizes. Visible-light estimates of an asteroid's size can be deceiving, because a small, light-colored space rock can look the same as a big, dark one. In infrared, however, a big dark rock will give off more of a thermal, or infrared glow, and reveal its true size. This size information will give researchers a better estimate of how often Earth can expect potentially devastating impacts.

"We are thrilled to have found our first new near-Earth object," said Amy Mainzer of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Mainzer is the principal investigator of NEOWISE, a program to mine the collected WISE data for new solar system objects. "Many programs are searching for near-Earth objects using visible light, but some asteroids are dark, like pavement, and don't reflect a lot of sunlight. But like a parking lot, the dark objects heat up and emit infrared light that WISE can see."

"It is great to receive the first of many anticipated near-Earth object discoveries by the WISE system," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at JPL. "Analysis of the WISE data will go a long way toward understanding the true nature of this population."

JPL manages the WISE mission for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. The ground-based observations are partly supported by the National Science Foundation.

Link: JPL News Release

Findings and Recommendations from NRC Report

Findings and Recommendations from the recent NRC NEO Report...

Finding: Congress has mandated that NASA discover 90 percent of all near-Earth objects 140 meters in diameter or greater by 2020. The administration has not requested and Congress has not appropriated new funds to meet this objective. Only limited facilities are currently involved in this survey/discovery effort, funded by NASA’s existing budget.Finding: w directing NASA to discover 90 percent of all near-Earth objects 140 meters in diameter or greater by 2020.

Finding: The selected approach to completing the George E. Brown, Jr. Near-Earth Object Survey will depend on nonscientific factors: If completion of the survey as close to the original 2020 deadline as possible is considered most important, a space mission conducted in concert with observations using a suitable ground-based telescope is the best approach. This combination could complete the survey well before 2030, perhaps as early as 2022 if funding were appropriated quickly. A peerreviewed competition would be held to select this mission. If cost conservation is deemed most important, the use of a large ground-based telescope is the best approach. Under this option, the survey could not be completed by the original 2020 deadline, but could be completed before 2030. To achieve the intended costeffectiveness, the funding to construct the telescope must come largely on the basis of non-NEO programs.

Recommendation: Because recent studies of meteor airbursts have suggested that near-Earth objects as small as 30 to 50 meters in diameter could be highly destructive, surveys should attempt to detect as many 30- to 50-meter objects as possible. This search for smaller-diameter objects should not be allowed to interfere with the survey for objects 140-meters in diameter or greater.

Finding: The Arecibo and Goldstone radar systems play a unique role in the characterization of NEOs, providing unmatched accuracy in orbit determination, and insight into size, shape, surface structure, and other properties for objects within their latitude coverage and detection range.

Recommendation: Immediate action is required to ensure the continued operation of the Arecibo Observatory at a level sufficient to maintain and staff the radar facility. Additionally, NASA and NSF should support a vigorous program of radar observations of NEOs at Arecibo and NASA should support such a program at Goldstone for orbit determination and characterization of physical properties.

Recommendation: The United States should initiate a peer-reviewed, targeted research program in the area of impact hazard and mitigation of NEOs. Because this is a policy driven, applied program, it should not be in competition with basic scientific research programs or funded from them. This research program should encompass three principal task areas: surveys, characterization, and mitigation. The scope should include analysis, simulation, and laboratory experiments. This research program does not include mitigation space experiments or tests which are treated elsewhere in this report.

Recommendation: The United States should take the lead in organizing and empowering a suitable international entity to participate in developing a detailed plan for dealing with the NEO hazard.

Recommendation: Data from NEO airburst events observed by the U.S. Department of Defense satellites should be made available to the scientific community to allow it to improve understanding of the NEO hazards to Earth.

NRC Final Report Release on NEOs: " Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies: Final Report"

National Research Council Final Report on NEOs: Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies: Final Report (2010) Aeronautics and Space Engineering Board (ASEB).

From the National Academies News Release...

Report Examines Options for Detecting and Countering Near-Earth Objects

WASHINGTON -- A new report from the National Research Council lays out options NASA could follow to detect more near-Earth objects (NEOs) – asteroids and comets that could pose a hazard if they cross Earth's orbit. The report says the $4 million the U.S. spends annually to search for NEOs is insufficient to meet a congressionally mandated requirement to detect NEOs that could threaten Earth.

Congress mandated in 2005 that NASA discover 90 percent of NEOs whose diameter is 140 meters or greater by 2020, and asked the National Research Council in 2008 to form a committee to determine the optimum approach to doing so. In an interim report released last year, the committee concluded that it was impossible for NASA to meet that goal, since Congress has not appropriated new funds for the survey nor has the administration asked for them.

In its final report, the committee lays out two approaches that would allow NASA to complete its goal soon after the 2020 deadline; the approach chosen would depend on the priority policymakers attach to spotting NEOs. If finishing NASA's survey as close as possible to the original 2020 deadline is considered most important, a mission using a space-based telescope conducted in concert with observations from a suitable ground-based telescope is the best approach, the report says. If conserving costs is deemed most important, the use of a ground-based telescope only is preferable.

The report also recommends that NASA monitor for smaller objects – those down to 30 to 50 meters in diameter -- which recent research suggests can be highly destructive. However, the report stresses that searching for smaller objects should not interfere with first fulfilling the mandate from Congress. Beyond completion of that mandate, the report notes the need for constant vigilance in monitoring the skies, so as to detect all dangerous NEOs. In addition, the nation should undertake a peer-reviewed research program to better investigate the many unknown aspects connected with detecting NEOs and countering those that could be a threat. The U.S. should also take the lead in organizing an international entity to develop a detailed plan for dealing with hazards from these objects.

In addition, the report recommends that immediate action be taken to ensure the continued operation of the Arecibo Observatory in Puerto Rico. NASA and NSF should support a vigorous program of NEO observations at Arecibo, and NASA should also support such a program at the Goldstone Deep Space Communications Complex. Although these facilities cannot discover NEOs, they play an important role in accurately determining the orbits and characterizing the properties of NEOs within radar range.

The Scope of the Hazard

Near-Earth objects are asteroids and comets that orbit the sun and approach or cross Earth's orbit. An asteroid or comet about 10 kilometers in diameter struck the Yucatan peninsula 65 million years ago and caused global devastation, probably wiping out large numbers of plant and animal species including the dinosaurs. Objects as large as this one strike Earth only about once every 100 million years on average, the report notes. NASA has been highly successful at detecting and tracking objects 1 kilometer in diameter or larger, and continues to search for these large objects. Objects down to sizes of about 140 meters in diameter -- which NASA has been mandated to survey for -- would cause regional damage; such impacts happen on average every 30,000 years, the report says.

While impacts by large NEOs are rare, a single impact could inflict extreme damage, raising the classic problem of how to confront a possibility that is both very rare and very important. Far more likely are those impacts that cause only moderate damage and few fatalities. Conducting surveys for NEOs and detailed studies of ways to mitigate collisions is best viewed as a form of insurance, the report says. How much to spend on these insurance premiums is a decision that must be made by the nation's policymakers.

Mitigating Damage

The report also examines what is known about methods to defend against NEOs. These methods are new and still immature. No single approach is effective for the full range of near-Earth objects, the committee concluded. But with sufficient warning, a suite of four types of mitigation is adequate to meet the threat from all NEOs, except the most energetic ones.

- Civil defense (evacuation, sheltering in place, providing emergency infrastructure) is a cost-effective mitigation measure for saving lives from the smallest NEO impact events and is a necessary part of mitigation for larger events.

- "Slow push" or "slow pull" methods use a spacecraft to exert force on the target object to gradually change its orbit to avoid collision with the Earth. This technique is practical only for small NEOs (tens of meters to roughly 100 meters in diameter) or possibly for medium-sized objects (hundreds of meters), but would likely require decades of warning. Of the slow push/pull techniques, the gravity tractor appears to be by far the closest to technological readiness.

- Kinetic methods, which fly a spacecraft into the NEO to change its orbit, could defend against moderately sized objects (many hundreds of meters to 1 kilometer in diameter), but also may require decades of warning time.

- Nuclear explosions are the only current, practical means for dealing with large NEOs (diameters greater than 1 kilometer) or as a backup for smaller ones if other methods were to fail.

Although all of these methods are conceptually valid, none is now ready to implement on short notice, the report says. Civil defense and kinetic impactors are probably the closest to readiness, but even these require additional study prior to reliance on them.

Given the significant unknowns about many aspects of the threat and its mitigation, the report recommends that the U.S. start a peer-reviewed, targeted research program on the hazards posed by NEOs, and how to deal with them. Because this is a policy-driven, applied research program, it should not be in competition with basic scientific research programs or be funded from them, the report adds.

The study was sponsored by NASA at the request of Congress. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, nonprofit institutions that provide science, technology, and health policy advice under a congressional charter. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.

Link: NRC Report (Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies: Final Report)

Link: National Academies Press Release

NEO Related Highlights from the Upcoming 41st Lunar and Planetary Science Conference March 1–5, 2010

Here are some selected sessions and specific papers from those sessions related to NEOs that will be presented at the upcoming 41st Lunar and Planetary Science Conference March 1–5, 2010 in Houston, Texas.

Session 251:
Tuesday, March 2, 2010
UREILITIC ASTEROIDS: INSIGHTS FROM ALMAHATA SITTA
1:30 p.m. Waterway Ballroom 1
Abstracts

Session 252:
Tuesday, March 2, 2010
VESTA AND DAWN
3:15 p.m. Waterway Ballroom 1
Abstracts

Session 313:
Tuesday, March 2, 2010
POSTER SESSION I: SMALL BODY MISSIONS
7:00 p.m. Town Center Exhibit Area

Nathues A. Reddy V. Schaeff S. Wiegand A. Michelsen R. Sanchez J. A. Boehnhardt H.
Ground-based Mineralogical Characterization of low Δv ASTEX Mission Targets [#1047]
ASTEX is an in situ exploration mission study to two near-Earth asteroids for which we have identified target candidates. Since many of the potential targets are without compositional information we have started a spectral survey.

Murdoch N. Rozitis B. Michel P. Losert W. de Lophem T-L. Green S. F.
AstEx Microgravity Experiment: Simulating Asteroid Regoliths [#1715]
This experiment aims to characterise the response of granular material to rotational shear forces in a microgravity environment in order to help design an asteroid sampling mechanism and interpret the fascinating geology found on asteroids.

Mainzer A. K. Masiero J. Bauer J. M. Grav T. Cutri R. McMillan R. Walker R. Wright E. L. WISE Team
WISE Solar System Research – Clearer Views of the Darkest Objects [#2505]
The WISE mission will be capable of performing a vast array of solar system observations. WISE will observe and detect thousands of main-belt asteroids and hundreds of near-Earth objects, providing IR-derived diameters and albedos for many of these bodies.

Grav T. Bauer J. M. Dailey J. Mainzer A. K. Cutri R. Masiero J. McMillan R. Walker R. Wright E. L.
WISE Preliminary Detection Statistics of Minor Planets [#2320]
We present the preliminary detection statistics of moving objects from the first two months of WISE scan operations discuss such topics as survey efficiency, pipeline reliability and orbit determination accuracy.

Bauer J. M. Grav T. Dailey J. Myers J. Mainzer A. K. Masiero J. Cutri R. McMillan R. Jedicke R. Denneau L. Walker R. Wright E. L. WISE Team
The WISE Moving Object Pipeline Subsystem — Design and Implementation [#2466]
WISE will detect a large number of solar system bodies, a large fraction of which have been previously unknown. We describe the design and implementation of the moving object detection subsystem for the spacecraft imaging data.

Masiero J. Mainzer A. Grav T. Delbó M. Mueller M. WISE Team
The WISE Survey of the Albedo Distribution of Main Belt Asteroids [#1283]
Using date from the Wide-field Infrared Survey Explorer (WISE) we investigate the albedo distribution across the main belt of asteroids. When complete WISE will measure albedos and diameters for ~100,000 asteroids.

Bauer J. M. Grav T. Mainzer A. K. Masiero J. Cutri R. Dailey J. McMillan R. Walker R. Wright E. L. WISE Team
WISE and the Outer Solar System — Searching for Objects in “The Back Forty” (AU) [#2418]
The vast majority of objects observed by the WISE mission will be in the inner solar system. However, several larger solar system objects beyond 5 AU will also be imaged. We will present an overview of outer solar system object observations to date.

Session 336:
Tuesday, March 2, 2010
POSTER SESSION I: MISSION PLANS AND CONCEPTS
7:00 p.m. Town Center Exhibit Area

Klaus K. Cook T. S. Smith D. B.
Small Body Landers for Near Earth Object Missions [#1077]
We are developing a small body lander product line that leverages the significant investments that have been made in the highly successful DARPA Orbital Express program.

Smith D. B. Klaus K. Caplin G. Elsperman M. S. Horsewood J.
Low Cost Multiple Near Earth Object Missions [#1464]
Our Commercial spacecraft are available with efficient high power solar arrays and hybrid propulsion systems (Chemical and Solar Electric) that make possible multiple Near Earth Object Missions within Discovery budget limits.

Lee P. Veverka J. Bellerose J. Boucher M. Boynton J. Braham S. Gellert R. Hildebrand A. Manzella D. Mungas G. Oleson S. Richards R. Thomas P. C. West M. D.
Hall: A Phobos and Deimos Sample Return Mission [#1633]
Hall is a proposed NASA-led New Frontiers-class international robotic lander and sample return mission to explore and return samples from the two moons of Mars, Phobos and Deimos.

Farnham T. Gaskell R. Gim Y. Heggy E. Klaasen K. Kofman W. Kreslavsky M. Lisse C. McFadden L. Pettinelli E. Plaut J. Scheeres D. Turtle E. Weissman P. Wu R.
Deep Interior Radar Imaging of Comets [#2670]
Deep Interior is a comet rendezvous mission using a high heritage planetary sounding radar to derive a high definition image of the global interior.

Session 553:
Thursday, March 4, 2010
SPECIAL SESSION: CHARACTERIZING NEAR-EARTH OBJECTS
1:30 p.m. Waterway Ballroom 4

Cheng A. * Barnouin O. S.
Eros and Itokawa Comparisons: NEAR Shoemaker and Hayabusa [#2747]
NEAR and Hayabusa have studied two S-type near-Earth asteroids with similar compositions, but with distinct internal structures and surface geologies. What does surface geology, in the form of lineaments, craters, and small surface features, tell us about strength and cohesion?

Yoshikawa M. * Kawaguchi J. Yano H. Hayabusa Mission Team Hayabusa Science Team
Asteroid Sample Return Mission Hayabusa, Its Engineering Challenges and Scientific Results [#2746]
Asteroid explorer Hayabusa will come back to the Earth in June 2010. We overcame many engineering difficulties and obtained many scientific data about the tiny S-type asteroid Itokawa. We summarize engineering and the scientific results of Hayabusa.

Benner L. A. M. *
Arecibo and Goldstone Radar Imaging of Near-Earth Asteroid [#2748]
Radar is the most powerful ground-based astronomical technique for studying the physical properties of near-Earth objects and for refining their orbits, principally through its ability to achieve resolutions as fine as several meters/pixel that can spatially resolve small objects.

Mainzer A. K. * Bauer J. M. Masiero J. Grav T. Cutri R. McMillan R. Walker R. Wright E. L. WISE Team
NEOWISE — The WISE Near Earth Object Survey [#2534]
The WISE spacecraft is expected to observe roughly 700 near-Earth objects, more than a third newly discovered. These measurements will provide a relatively unbiased and uniform sampling of this small body sub-population down to sizes of a few hundred meters.

Emery J. P. * Fernández Y. R. Kelley M. S. Hergenrother C. Ziffer J. Lauretta D. S. Drake M. J. Campins H.
Thermophysical Characterization of Potential Spacecraft Target (101955) 1999 RQ36 [#2282]
We report on thermal emission measurements of 1999 RQ36 from Spitzer. The derived size is in agreement with radar measurements, and we find a moderately high thermal inertia and homogeneous surface properties.

Gaskell R. W. * Barnouin O. S. Scheeres D. J.
The NEAR Shoemaker Landing on Eros [#2093]
NEAR imaging and NLR data are being used to determine the spacecraft’s approach trajectory and final landing site.

Binzel R. P. * Morbidelli A. Merouane S. DeMeo F. E. Birlan M. Vernazza P. Thomas C. A. Rivkin A. S. Bus S. J. Tokunaga A. T.
Good Vibrations: Recent Near-Earth Encounters as the Missing Piece of the S-Asteroid and Ordinary Chondrite Meteorite Puzzle [#1226]
Close Earth encounters that induce seismic shaking of near-Earth asteroids are found to produce surfaces free of space weathering. These “Q-type asteroids” are direct spectral matches to the most commonly falling meteorites, the ordinary chondrites.

Gaffey M. J. * Reddy V.
Mineralogical Diversity in the S-Type NEA Population [#1864]
Mineralogically diagnostic spectral parameters derived from VNIR spectra of near-Earth asteroids confirm previous suggestions that LL-chondrite-like assemblages appear overrepresented in the NEA population relative to the meteorite fall population.

Scheeres D. J. * Hartzell C. M.
The Relevance and Role of Cohesive Forces for Small Asteroids [#1839]
A comparison of forces at asteroids shows that van der Waals cohesion between regolith grains is significant. Consideration of this effect as a function of grain size suggests a new model for the terminal evolution of rubble pile asteroids.

Jacobson S. A. * Scheeres D. J.
The Evolution of Binary Asteroids Formed by Spin Fission [#2098]
The mass ratio determines the evolution after a YORP spin-fission event. High mass ratio systems (>0.2) evolve to a tidally locked state. Low mass ratio systems (<0.2) disrupt, but may undergo secondary fission events that can stabilize the system.

Lasue J. * De Sanctis M. C. Capria M. T. Turrini D. Coradini A. Thermal Model of Comet Nuclei: Implications for Rosetta [#1675]We investigate the effect of shape, orbital history, obliquity and dust covering on the thermal properties and the activity of Comet 67P/Churyumov-Gerasimenko. Implications for the Rosetta mission timeline are derived. 41st Lunar and Planetary Science Conference (2010) sess553.pdf

Link: Abstracts for 41st Lunar and Planetary Science Conference (March 1–5, 2010) [PDF]

Osiris-Rex: New Frontiers Mission Proposal

The OSIRIS-REX mission recently was one of three down-selected mission concepts to get US$3.3 million in 2010 to conduct a 12-month mission concept study that focuses on implementation feasibility, cost, management and technical plans. Studies also will include plans for educational outreach and small business opportunities. The studies will begin this year, and the selected mission must be ready for launch no later than Dec. 30, 2018. Mission cost, excluding the launch vehicle, is limited to $650 million. (source: NASA Ames Press Release). Also more information on the selection announcement at this NASA Press Release. Also the spacecraft's twitter feed. Older OSIRIS presentation given a few years ago at ESA.

Selections from a blogpost by Future Planetary Exploration about OSIRIS-Rex.

1) The target asteroid is the same as for OSIRIS' previous incarnation as a Discovery-class mission: 1999 RQ36, a "B-class" carbonaceous asteroid made of primitive material from the Solar System's early history that has not undergone extensive heating and thus modification since it was incorporated into the original Main Belt asteroid of which RQ36 is a broken-away fragment.

(2) 1999 RQ36 has several important characteristics. It's the darkest-colored asteroid yet measured (reflecting only 3% of the sunlight that hits it), which means that it must be made of particularly carbon-rich minerals exposed to minimal heating -- almost certainly including substantial amounts of fairly complex organic molecules. It has been substantially examined and mapped both by the ground-based Arecibo radar observatory and the infrared Spitzer Space Telescope -- which have provided data both on its overall size, shape and rotation, and on its overall composition (the asteroid not only has "a spectral signature suggesting a carbon- and volatile-rich surface", but apparently has a good deal of loose regolith on its surface that can be easily sampled by a spacecraft).

(3) And 1999 RQ36 also happens to have "the highest probability of impacting the Earth of any known Potentially Hazardous Asteroid" -- specifically, a one-in-1800 chance of hitting Earth in 2170. OSIRIS REx, during its year or so of orbiting the asteroid before finally dipping briefly to its surface for sampling, will allow Earth tracking stations to determine the asteroid's orbit with extreme precision -- thus further allowing forecasts of the probability of its striking Earth (as well as allowing the best measurements yet of the "Yarkovsky Effect" by which the absorption and reflection of sunlight by different parts of a rotating asteroid can actually produce a faint but significant thrust that modifies its orbit).

(4) OSIRIS REx is scheduled to collect and return an absolute minimum of 60 grams (about two ounces) of material from the asteroid's surface -- but it has the ability, if conditions are favorable, to return as much as two kilograms of material (about 4 1/2 pounds). It will not only map the global chemical, mineralogical and physical structure of the asteroid to put the returned sample in perspective, but will "document the texture, morphology, volatile chemistry, and spectral properties of the regolith at the sampling site in situ at scales down to the sub-millimeter" -- presumably using some instruments attached to the boom-mounted sampling device itself (which can flex like an arm to load the sample into the Earth return capsule mounted on the spacecraft's side).

(5) The craft will use scanning lidar (laser radar) to steer itself to precise courses around the asteroid and down to appropriate spots on its surface, enabling it to acquire samples "with no time-critical events" -- that is, once it has descended to near the surface and matched the asteroid's rotation rate, it can collect its samples in a leisurely way according to what its navigational instruments tell it, instead of having to work against a tight time deadline. It will also provide more practice to ground controllers in carrying out such precision movements around a small body such as an asteroid or comet nucleus.

(6) OSIRIS REx is a cooperative effort by the Goddard Space Flight Center, the University of Arizona, and Lockheed Martin (which would build the craft) -- but it also includes one science instrument from Arizona State University (a thermal infrared spectrometer), and another unspecified one from the Canadian Space Agency.

Russian Scientists Discuss NEOs

"Russian scientists brace for approaching asteroid"
Russia Today (RT)
Published 20 January, 2010, 08:48

Russia’s space agency has been holding meetings about Apophis – the asteroid due to pass close to Earth in 2029. If it is not diverted, a collision could potentially kill millions, scientists say. “Apophis was discovered in 2004,” explains Boris Shustov, Director of the Institute of Astronomy. “The probability of a collision with the Earth was very high, about 1 to 30. The collision of such a large body with our planet will cause great damage."

Link: Russia Today News Report (20 January 2010)





"Armageddon 2036: Russian scientists say no"
Russia Today (RT)
Published 31 December, 2009, 01:52

A huge asteroid, 350 meters in diameter, will come dangerously close to Earth, risking a lethal crash with our planet. However, Russian Federal Space Agency says there are ways to avert the collision. A celestial body named Apophis – asteroid 2004 MN4 – is considered the greatest space danger for Earth. In 2029 it will pass within 30 thousand kilometers of Earth, closer than some orbital satellites. The greater danger, though, is to be expected in 2036 when the next encounter with Earth by the asteroid is planned – the trajectory of the celestial body is expected to change so that the collision is quite likely, the head of Federal Space Agency, Anatoly Perminov, said in an interview with the Voice of Russia radio. He mentioned the data comes from research by an unnamed scientist claiming the accident is almost inevitable.

Link: Russia Today News Report (31 December 2009)

2010 Mexico City Workshop on global asteroid monitoring network

Recently concluded workshop following upon the report last year by Association of Space Explorers (ASE) Committee on Near-Earth Objects (NEOs) and its Panel on Asteroid Threat Mitigation on recommendations for global information, mitigation, and decision-making as related to planetary defense. 

The Association of Space Explorers co-sponsored with the Secure World Foundation a January workshop in Mexico City on an international Information, Analysis, and Warning network [IAWN] to distribute reliable information on hazardous NEOs. This is part of the proposal laid out in the ASE report for an IAWN.

Link: Astronaut Tom Jones Blog Article

Article: Sudan arrests Europeans over asteroid fragments

From Reuters:

KHARTOUM, Jan 19 (Reuters) - Sudanese police said on Tuesday they had arrested two European tourists for collecting fragments of an asteroid from the country's northern desert without permission.

The tourists, from France and Belgium, found pieces of an asteroid that crashed to earth in the Abu-Hamad area of Sudan's remote Northern state, said a statement published by Sudan's interior ministry.

"This was a clear violation and an illegal act because they didn't get the right permission from the geological or other relevant authorities," a police spokesman told Reuters.

The statement did not say what charges the Europeans might face.

Scientists tracked a car-sized asteroid as it entered the Earth's atmosphere and exploded over northern Sudan's Nubian desert in October 2008.

Experts from NASA and the University of Khartoum, collected fragments from the site soon afterwards.

They described the find as extremely rare as fragile asteroids usually explode high in the atmosphere and because it was the first time scientists had been able to predict an object was heading to earth and follow it to its final destination.

Sudan has very few tourists, largely thanks to its insecurity, cumbersome visa regulations and the restrictions on visitors' movements imposed when they arrive.

Link: Reuters Article

Impact of Earth's Gravity on Nearby Asteroids

From MIT News Release...

For decades, astronomers have analyzed the impact that asteroids could have on Earth. New research by MIT Professor of Planetary Science Richard Binzel examines the opposite scenario: that Earth has considerable influence on asteroids — and from a distance much larger than previously thought. The finding helps answer an elusive, decades-long question about where most meteorites come from before they fall to Earth and also opens the door to a new field study of asteroid seismology.

By analyzing telescopic measurements of near-Earth asteroids (NEAs), or asteroids that come within 30 million miles of Earth, Binzel has determined that if an NEA travels within a certain range of Earth, roughly one-quarter of the distance between Earth and the moon, it can experience a “seismic shake” strong enough to bring fresh material called “regolith” to its surface. These rarely seen “fresh asteroids” have long interested astronomers because their spectral fingerprints, or how they reflect different wavelengths of light, match 80 percent of all meteorites that fall to Earth, according to a paper by Binzel appearing in the Jan. 21 issue of Nature. The paper suggests that Earth’s gravitational pull and tidal forces create these seismic tremors.

By hypothesizing about the cause of the fresh surfaces of some NEAs, Binzel and his colleagues have tried to solve a decades-long conundrum about why these fresh asteroids are not seen in the main asteroid belt, which is between Mars and Jupiter. They believe this is because the fresh surfaces are the result of a close encounter with Earth, which obviously wouldn’t be the case with an object in the main asteroid belt. Only those few objects that have ventured recently inside the moon’s orbital distance and have experienced a “fresh shake” match freshly fallen meteorites measured in the laboratory, Binzel said.

Clark Chapman, a planetary scientist at the Southwest Research Institute in Colorado, believes Binzel’s work is part of a “revolution in asteroid science” over the past five years that considers the possibility that something other than collisions can affect asteroid surfaces. 

How they did it: Binzel’s team used a large NASA telescope in Hawaii to collect information on NEAs, including a huge amount of spectral fingerprint data. Analyzing this data, the group examined where a sample of 95 NEAs had been during the past 500,000 years, tracing their orbits to see how close they’d come to Earth. They discovered that 75 NEAs in the sample had passed well inside the moon’s distance within the past 500,000 years, including all 20 fresh asteroids in the sample.

Binzel next determined that an asteroid traveling within a distance equal to 16 times the Earth’s radius (about one-quarter of the distance to the moon) appears to experience vibrations strong enough to create fresh surface material. He reached that figure based on his finding that about one-quarter of NEAs are fresh, as well as two known facts — that the space weathering process that ages regolith can happen in less than one million years, and that about one-quarter of NEAs come within 16 Earth radii in one million years.

Before now, people thought an asteroid had to come within one to two Earth radii to undergo significant physical change.

Next steps: Many details about the shaking process remain unknown, including what exactly it is about Earth that shakes the asteroids, and why this happens from a distance as far away as 16 Earth radii. What is certain is that the conditions depend on complex factors such as the velocity and duration of the encounter, the asteroid’s shape and the nature of the preexisting regolith. “The exact trigger distance depends on all those seismology factors that are the totally new and interesting area for cutting edge research,” Binzel said.

Further research might include computer simulations, ground observations and sending probes to look at the surfaces of asteroids. Binzel’s next steps will be to try to discover counterexamples to his findings or additional examples to support it. He may also investigate whether other planets like Venus or Mars affect asteroids that venture close to them.


Link: MIT News Release 

From Discovery News Article...

New research published in this week's Nature shows Earth's gravity triggers ground-shifting quakes on asteroids passing as far as about 30 million miles away.

The findings may not only help scientists deflect an Earth-bound asteroid, but also provide fresh insights into the connections between asteroids and meteorites.

Scientists made the discovery by comparing differences in light reflected off asteroids that have breezed by Earth with those that orbit farther away. Though they are made of the same materials, the asteroids that encounter Earth's gravity have fresh surfaces that are noticeably less weathered by the space environment.
Scientists believe the resurfacing is due to slow-falling landslides, triggered by tidal forces from Earth.

"Asteroids get sunburned out there by the light from the sun, the radiation from the sun," Dan Durda, a planetary scientist with the Southwest Research Institute in Boulder, Colo., told Discovery News.

Backtracking the orbits of 95 near-Earth asteroids, scientists determined that over the past 500,000 years, 75 of them had passed closer to Earth than the moon, which is about 239,000 miles (or about 385,000 kilometers) away. The 75 asteroids included 20 bodies with spectra of fresh surface materials.

Link: Article (Discovery News)

Nature Magazine (editor's summary)..

The 'ordinary chondrite problem' has been a factor in Solar System astronomy for three decades. It refers to the apparent anomaly that whereas about 80% of the meteorites falling to Earth are 'ordinary chondrites', they are rare among asteroids. The usual explanation is that 'space weathering' processes alter ordinary chondrite surfaces, producing reddened 'S-type' asteroids. A mystery remains, though, in the shape of a rare class of asteroids, the Q-types. These are found only near the Earth, and they do display 'fresh' spectral matches to ordinary chondrites. Now the combination of a new data set of 95 asteroid spectra with their detailed orbital histories shows that all Q-type asteroids have recently passed close to Earth at least within the lunar distance. Thus tidal stresses or seismic shaking during these encounters may have exposed new unweathered material on the surface. Intriguingly a test of this hypothesis may be at hand: 99942 Apophis, a potentially Earth-threatening asteroid currently displaying 'weathered' spectral colours, is due to pass within six orbital radii of Earth in 2029. It is predicted that it will experience a seismic 'fresh shake', which should expose new unreddened material on the surface. 

Link: Nature Magazine (Editor's Summary)

Asteroids: Stripped on passing by Earth

Nature 463, 305-306 (21 January 2010) | doi:10.1038/463305a; Published online 20 January 2010

Clark R. Chapman

Clark R. Chapman is in the Department of Space Studies, Southwest Research Institute, Boulder, Colorado 80302, USA.
Email: cchapman@boulder.swri.edu

Abstract:

Asteroids are weakly bound piles of rubble, and if one comes close to Earth, tides can cause the object to undergo landslides and structural rearrangement. The outcome of this encounter is a body with meteorite-like colours. We once thought that small asteroids were solid 'chips off the old block'. Instead, in a developing story, they are now known to be ephemeral piles of boulders in near-zero gravity, constantly evolving from delicate forces never before thought important.

Link: Nature Article (Asteroids: Stripped on passing by Earth) 

Earth encounters as the origin of fresh surfaces on near-Earth asteroids

Nature 463, 331-334 (21 January 2010) | doi:10.1038/nature08709; Received 2 October 2009; Accepted 18 November 2009

Richard P. Binzel^1,2, Alessandro Morbidelli³, Sihane Merouane⁴, Francesca E. DeMeo⁴, Mirel Birlan², Pierre Vernazza⁵, Cristina A. Thomas⁶, Andrew S. Rivkin⁷, Schelte J. Bus⁸ & Alan T. Tokunaga⁸

1. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2. Institut de Mecanique Celeste et de Calcul des Ephemerides (IMCCE), Observatoire de Paris, Paris 75014, France
3. Departement Cassiopee, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, Nice 06304, France
4. Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique (LESIA), Observatoire de Paris, Meudon 92195, France
5. ESTEC/ESA, Noordwijk 2200 AG, Netherlands
6. Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
7. Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723, USA
8. Institute for Astronomy, University of Hawaii, Hilo, Hawaii 96720, USA

Correspondence to: Richard P. Binzel^1,2 Correspondence and requests for materials should be addressed to R.P.B. (Email: rpb@mit.edu).

Abstract:

Telescopic measurements of asteroids’ colours rarely match laboratory reflectance spectra of meteorites owing to a ‘space weathering’^{1, 2} process that rapidly³ reddens asteroid surfaces in less than 10⁶ years. ‘Unweathered’ asteroids (those having spectra matching the most commonly falling ordinary chondrite meteorites), however, are seen among small bodies the orbits of which cross inside Mars and the Earth. Various explanations have been proposed for the origin of these fresh surface colours, ranging from collisions⁴ to planetary encounters⁵. Less reddened asteroids seem to cross most deeply into the terrestrial planet region, strengthening⁶ the evidence for the planetary-encounter theory⁵, but encounter details within 10⁶ years remain to be shown. Here we report that asteroids displaying unweathered spectra (so-called ‘Q-types’⁷) have experienced orbital intersections closer than the Earth–Moon distance within the past 5 × 10⁵ years. These Q-type asteroids are not currently found among asteroids showing no evidence of recent close planetary encounters. Our results substantiate previous work⁵: tidal stress⁸, strong enough to disturb and expose unweathered surface grains, is the most likely dominant short-term asteroid resurfacing process. Although the seismology details are yet to be worked out, the identification of rapid physical processes that can produce both fresh and weathered asteroid surfaces resolves the decades-long⁹ puzzle of the difference in colour of asteroids and meteorites.

Link: Nature Letter (Earth encounters as the origin of fresh surfaces on near-Earth asteroids) 

Radar returns from asteroid 2010AL30

From the Planetary Society blog...

Goldstone detects "STRONG" radar echoes from 2010 AL30
Jan. 12, 2010 | 21:05 PST
Radio scientist Lance Benner posted to the Minor Planets Mailing list this evening the following message:

All,

We have detected STRONG radar echoes from 2010 AL30 at Goldstone. The bandwidth is consistent with the object's expected size and the ~9 minute rotation period found by Bill Ryan and Richard Miles. We hope to obtain a precise size estimate soon.

The Doppler correction came in at about the 1-sigma level relative to our a priori estimate. We're updating the ephemeris now. Thank you again for all your help!
Nine-minute rotation? That is fast!! The observations of 2010 AL30 from Goldstone took place from 2:20 to 4:40 UTC on January 13.

When Benner says "thank you for all your help," his message is addressed to amateur astronomers around the world who pointed their telescopes at 2010 AL30 upon its approach, gathering information that helped to refine its orbit. In an earlier message to the group, Benner said "The pointing uncertainties have shrunk from about 523 arcseconds to about 11 arcsec at the start of tonight's track. Without all the astrometry you have reported, our observations would not be possible."

Although no backyard 'scope can equal the capability of Goldstone to measure the shape, size, and physical properties of an asteroid, Goldstone depends upon accurate positional information for its pointing. I'm sure they could have detected 2010 AL30 with less precise information; but to point in exactly the right direction results in much stronger echoes from the asteroid, improving the quality of their data by leaps and bounds. And being able to point so precisely might have been what allowed Benner to get time on such an important instrument on such short notice -- I'm not sure.

That's my favorite aspect of the study of near-Earth objects: the way that the science benefits from the participation of people at extremes of the observing spectrum, from the serious but amateur backyard astronomer to the scientists who run the world's largest telescopes.

I'll keep my eyes peeled for further science results from Goldstone's observations of 2010 AL30, and remember how they benefited from the help of amateurs.

A final note: JPL issued a statement this afternoon that contradicted some speculation across the Web, that because 2010 AL30 has a 1-year orbit that it might be an Earth artifact -- a lost rocket stage or some such thing. Although it does have a 1-year orbital period, "this object's orbit reaches the orbit of Venus at its closest point to the sun and nearly out to the orbit of Mars at its furthest point, crossing the Earth's orbit at a very steep angle. This makes it very unlikely that 2010 AL30 is a rocket stage. Furthermore, trajectory extrapolations show that this object cannot be associated with any recent launch and it has not made any close approaches to the Earth since well before the Space Age began. It seems more likely that this is a near-Earth asteroid about 10-15 meters in size...."

Asteroid 2010 AL30 Close Approach on January 13, 2010 (76,000 miles)

Orbital diagram depicts the trajectory of asteroid 2010 AL30 during its flyby of Earth in the early morning hours of Jan. 13 (Credit: NASA JPL)

2010 AL30 as imaged remotely from Australia on Jan. 11, 2010 (Ernesto Guido & Giovanni Sostero)

 
From NASA JPL:

Asteroid 2010 AL30, discovered by the LINEAR survey of MIT's Lincoln Laboratories on Jan. 10, will make a close approach to the Earth's surface to within 76,000 miles on Jan. 13 at 12:46 pm Greenwich time (7:46 am EST, 4:46 am PST). Because its orbital period is nearly identical to the Earth's one year period, some have suggested it may be a manmade rocket stage in orbit about the sun. However, this object's orbit reaches the orbit of Venus at its closest point to the sun and nearly out to the orbit of Mars at its furthest point, crossing the Earth's orbit at a very steep angle. This makes it very unlikely that 2010 AL30 is a rocket stage. Furthermore, trajectory extrapolations show that this object cannot be associated with any recent launch and it has not made any close approaches to the Earth since well before the Space Age began.

It seems more likely that this is a near-Earth asteroid about 10-15 meters in size, one of approximately 2 million such objects in near-Earth space. One would expect a near-Earth asteroid of this size to pass within the moon's distance about once every week on average. The asteroid does not pose a risk, in fact, stony asteroids under 25 meters in diameter would be expected to burn up in our atmosphere, causing little or no ground damage.

Link: NASA JPL Asteroid Watch

Link: Discovery News 

UN COPUOS Scientific and Technical Subcommittee for February 2010: NEO Portion

From the agenda for the UN COPUOS Scientific and Technical Subcommittee meeting (8-19 February 2010, United Nation Office at Vienna, Vienna International Center, Vienna, Austria). The section on NEOs follows:

12. Near-Earth objects
In paragraph 9 of its resolution 64/86, the General Assembly agreed that the Subcommittee should reconvene its Working Group on Near-Earth Objects.

The Working Group will continue the work begun during the intersessional period on drafting international procedures for handling the threat posed by near-Earth objects (NEOs) and seek agreement on those procedures, review progress on international cooperation and collaboration on NEO observations, and facilitate, for the purpose of NEO threat detection, a more robust international capability for the exchange, processing, archiving and dissemination of data.9 The Subcommittee will have before it a report containing information on research in the field of near-Earth objects carried out by member States, international organizations and other entities (A/AC.105/949). In addition, the fourth interim report of the Action Team on Near-Earth Objects will be made available to the Subcommittee.

Link: Scientific and Technical Subcommittee: 2010, Forty-seventh session, 8-19 February 2010.

Article: NASA’s Flexible Path evaluation of 2025 human mission to visit an asteroid

Selections from the article...

NASA managers have created an evaluation and roadmap for a potential human mission to visit the 1999 AO10 Near Earth Object (NEO) as early as 2025, as part of their options under the Flexible Path approach to the future of Human Space Flight. The mission would focus on using the International Space Station (ISS) as a testbed, with the ultimate focus on eventually heading to Mars.

However, the internal 65 page Flexible Path presentation – available on L2 – presented several possible directions NASA may take under the Augustine Commission’s Flexible Path option, including the outlining of a NEO mission in the mid-2020s, a full five to six years after the original target date to return to the moon, as outlined in the Vision of Space Exploration (VSE) – which is no longer seen as achievable.

Further information on the number of NEOs and PHOs will be forthcoming via “Next Generation Surveys such as LSST & Pan-STARRS, along with current on-going surveys, (which) expect to find many more NEOs and PHOs. The next generation surveys includes: Tracking (for better orbit determination). Characterization (taxonomy, minerals, volatiles, etc.). NEO-WISE is expected to find a few hundred NEOs in the next year.”

Based on the NEOs of interest – ones which are potential targets for a sending an expedition to visit – NASA has estimated 39 are accessible “based on a flight system assumptions consistent with a single Ares V-class launch.”

These targets have been generated from a list of NEOs already identified as accessible by human missions lasting up to a year, along with the viable outbound transit time for typical robotic missions to the same targets – resulting in multiple opportunities for human missions, and multiple opportunities also for precursor robotic missions in earlier years.

The scenario that was chosen for the purpose of the proposal to visit a NEO, targets the NEO “1999 AO10″ – which holds three human launch opportunities in 2025, 2026 and 2032 – with three robotic precursor opportunities in 2019, 2020, or 2021.

For the scenario used by the Flexible Path presentation, a five to six month long duration flight is installed into the roadmap for the human expedition to the asteroid, and importantly is classed as a vital element of the overall mission – countering claims that robotics can carry out all the requirements of the mission on their own.

“A robotic precursor would have been conducted ~4 years prior to a human NEO mission. A typical piloted “sprint” mission would be ~155 days in duration,” continued the presentation.

“Instruments would include teleoperated rovers or hoppers (multiple trips to/from surface); multi-wavelength radar system (HGA could be used to perform radar tomography of the NEO to obtain internal structure); and small instrument packages for precision deployment by the crew during EVA or with a robotic rover system.

“The human crew would provide: adaptability and ingenuity to deal with complex issues in real time; direct interaction with the surface via a variety of methods; and wide-ranging E/PO activities including HD video of humans at another world.”

Link: SpaceflightNow Article

References for Previous Human NEO Missions

I have gathered several papers on previous human NEO mission design studies. These are listed on a separate references page.

Lockheed Martin Human Asteroid Mission Presentation

Charts from Lockheed Martin on their Human Asteroid Mission design ("Plymouth Rock: An Early Human Asteroid Mission Using Orion") are now available on the corporate website. This design study was was presented at the Small Bodies Assessment Group meeting in November 18–19, 2009 in Boulder, Colorado. Josh Hopkins and Adam Dissel from Lockheed Martin Space Systems presented the study.

The architecture utilizes two ETO launches: an Ares V with an unmanned Orion CEV + EDS and an Ares I with a manned Orion CEV. Thus the dual-Orion in-space configuration that has been talked about in the media. For an initial target 2008 EA9 was chosen for a 2019 opportunity (total mission DV = 4.9 km/s, total 205 Day mission duration).

Some quick observations from the study:

* Six months appears to be the upper limit of feasible mission durations using dual Orion (for two people)
* Repeat opportunities with a specific asteroid are usually decades apart
* At the current asteroid discovery rate, the number of known mission opportunities in this time frame may double by 2015
* Orion-based asteroid missions require launch of about 46 tons to C3 = +1 to +4 km2/s2 (slightly faster than escape velocity)
* This is roughly equivalent to launching 50-65 mt to translunar injection (C3 = -1.8 km2/s2) depending on the launch approach, the planned Ares V capability has margin for this mission

Link: Lockheed Martin Human Asteroid Mission Presentation Charts (NASA Small Bodies Assessment Group meeting, November 2009)

Link: General Lockheed Martin Orion Corporate Page