This area will cover relevant news of the threat to the planet from Near Earth Objects (NEOs) including concepts and designs for mitigation. All opinions are those of the author.

26 June 2006

Excitement Builds for July 3 Close Approach for 2004 XP14

Selected highlights from a recent article:

The size of 2004 XP 14 is not precisely known. But based on its brightness, the diameter is believed to be somewhere in the range of 1,345 to 3,018-feet (410 to 920 meters). That's between a quarter mile and just over a half-mile wide.

Due to the proximity of its orbit to Earth [Map] and its estimated size, this object has been classified as a “Potentially Hazardous Asteroid” (PNA) by the Minor Planet Center in Cambridge, Massachusetts. There are currently 783 PNAs.

The latest calculations show that 2004 XP14 will pass closest to Earth at 04:25 UT on July 3 (12:25 a.m. EDT or 9:25 p.m. PDT on July 2). The asteroid’s distance from Earth at that moment will be 268,624-miles (432,308 km), or just 1.1 times the Moon’s average distance from Earth.

The size of 2004 XP 14 is not precisely known. But based on its brightness, the diameter is believed to be somewhere in the range of 1,345 to 3,018-feet (410 to 920 meters). That's between a quarter mile and just over a half-mile wide.

Due to the proximity of its orbit to Earth [Map] and its estimated size, this object has been classified as a “Potentially Hazardous Asteroid” (PNA) by the Minor Planet Center in Cambridge, Massachusetts. There are currently 783 PNAs.

The latest calculations show that 2004 XP14 will pass closest to Earth at 04:25 UT on July 3 (12:25 a.m. EDT or 9:25 p.m. PDT on July 2). The asteroid’s distance from Earth at that moment will be 268,624-miles (432,308 km), or just 1.1 times the Moon’s average distance from Earth.

"Huge Asteroid to Fly Past Earth July 3"
Joe Rao
26 June 2006


Back: At the NASA NEO Workshop in Vail Colorado


I am at the NASA NEO Workshop take is taking place in Vail, Colorado from June 26-30, 2006. I will attempt to keep everyone updated as to the various events. Look for my updates at the end of each day.

Link: NEO Workshop Agenda

02 June 2006

Asteroid Itokawa is a Rubble Pile (Porosity of 40%, like sand)

"A small near-Earth asteroid recently visited by a Japanese spacecraft is little more than a "rubble pile" of loosely-pack debris from other asteroid collisions, scientists conclude. In papers published in this week's issue of the journal Science, planetary scientists said studies of the asteroid Itokawa by the Japanese spacecraft Hayabusa showed that the asteroid's surface was littered with small boulders and gravel, leading scientists to conclude that the asteroid is not a monolithic rock but instead debris from a previous asteroid collision held together by its own gravity. The asteroid has a porosity of 40%, further evidence that the object is loosely packed together. Spectroscopic analysis of the asteroid turned up evidence of iron and minerals such as olivine and pyroxene, although no signs of differentiation."

Link: SpaceToday

Possible 250 MYear Impact Crater in Antarctica: 30 Miles Wide

A little late getting to this story, but nonetheless I find it interesting that simultaneously our technology allows us to find more evidence of past impacts, it is also allowing us to find future threatening objects. Selected quotes from a article below:

An apparent crater as big as Ohio has been found in Antarctica. Scientists think it was carved by a space rock that caused the greatest mass extinction on Earth, 250 million years ago.

The crater, buried beneath a half-mile of ice and discovered by some serious airborne and satellite sleuthing, is more than twice as big as the one involved in the demise of the dinosaurs.

The newfound crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub space rock is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide, the researchers said.

"Giant Crater Found: Tied to Worst Mass Extinction Ever"
Robert Roy Britt
01 June 2006

Link: article

30 May 2006

Update on NASA NEO Workshop (June 26-29, 2006

Updates from NASA on the Near Earth Object (NEO) Workshop

- NASA will continue to accept abstract submissions for the Workshop through NSPIRES until June 2nd, 2006. Priority will be given to those abstracts submitted by the original date.

- The NASA NEO Workshop will be held in Vail (CO) from June 26 through June 29, 2006.


22 May 2006

Another Article on Slight Threat Reduction of Apophis

"Before this observation, it was thought that in 2029 Apophis would approach our planet to within about 5.86 Earth radii. With these new measurements, the estimated distance has been pushed back to 5.93 Earth radii."

"In January, Tholen [Dave Tholen, astronomer, University of Hawaii, US] and his team plan to observe Apophis to determine its rotation rate. This is important because if the asteroid is heated unevenly by sunlight, the radiation can impart a small force on the asteroid. That force may be miniscule, but when it accumulates over 20 years, it can make the difference in whether Apophis passes through the keyhole or not, he says."

"Risk of asteroid smashing into Earth reduced"
Kelly Young
22 May 2006


19 May 2006

Possible Reduction of Threat from Apophis in 2036

New Arecibo radar data has allowed better calculations of the trajectory of Apophis. Cumulative probability of impact (from JPL NEOPO Sentry Assessment) changed from 1.6e-04 (on 14 April 2006) to 4.4e-05 (on 18 May 2006). I have quoted multiple sections from a recent article below:

The chances of collision with the asteroid Apophis in 2036 now stand at 1 in 24,000, said Steve Chesley, an expert on near-Earth objects at NASA's Jet Propulsion Laboratory. That's a significant advance from the previous orbital predictions, which set the odds of impact at 1 out of about 6,000.

The May 6-7 window for radar observations represented the best opportunity until the end of 2012. Jon Giorgini, a senior analyst for the Solar Systems Dynamics Group at JPL, said the Arecibo team got a good fix on Apophis. "We were able to improve our understanding of its motion by about 6 millimeters per second," Giorgini.

Previously, NASA had said that no more observations could be made until 2013. But on Thursday, Chesley said more may be known before then. "Actually, we're going to probably get some observations, though they'll be difficult to obtain — maybe by next spring," he said. Astronomers at the Mauna Kea Observatory in Hawaii could spot the asteroid in 2007 as well as in 2011, he said.

In the 2012-2013 time frame, Arecibo could come into play again. Giorgini said those observations would be even more accurate because Apophis would come within 8.3 million miles (13 million kilometers) of Earth — much closer than this month's pass at a distance of 26 million miles (42 million kilometers).

"Asteroid risk to Earth lowered, scientists say: Chances of impact move ‘in right direction,’ toward odds of 1-in-24,000"
Alan Boyle
Science editor
18 May 2006

Link: MSNBC Article

"99942 Apophis No Longer a Threat for 2036"
18 May 2006

17 May 2006

Article on Upcoming NEO Workshop

NASA Authorization Act of 2005 includes the following (passed by Congress late in 2005, and signed by the President):

"The U.S. Congress has declared that the general welfare and security of the United States require that the unique competence of NASA be directed to detecting, tracking, cataloguing, and characterizing near-Earth asteroids and comets in order to provide warning and mitigation of the potential hazard of such near-Earth objects to the Earth,"

Now comes a new, four day workshop on NEO mitigation threats to engage experts. Hosted by ASA’s Office of Program Analysis & Evaluation, this workship in late June/early July is to examine:

- Detection, Tracking and Cataloging NEOs
- Characterization of NEOs, and
- Deflection or other forms of NEO Threat Mitigation

"NASA to Look into NEO Threat Response Proposals"
Leonard David
16 May 2006


15 May 2006

ISDC 2006 Presentation from Rusty Schweickart (B612 Foundation

"NEOs: The Katrinas of the Cosmos"
Presentation to the International Space Development Conference
6 May 2005
Russell Schweickart

Link: ISDC 2006 Paper

Article on Current NEO Threat Situation

"Certainly we had a major credibility problem at the beginning - a giggle factor," said David Morrison, an astrobiologist at NASA's Ames Research Center in Mountain View, Calif. "Now, many people are aware this is something we can actually deal with, mitigate and defend against."

In 1998, lawmakers formally directed NASA to identify by 2008 at least 90 percent of the asteroids more than a kilometer (0.6 mile) wide that orbit the sun and periodically cross Earth's path. That search is now more than three-quarters complete.

Last year, Congress directed the space agency to come up with options for deflecting potential threats. Ideas seriously discussed include lasers on the moon, futuristic "gravity tractors," spacecraft that ram incoming objects and Hollywood's old standby, nuclear weapons.

To help explore possible alternatives, former Apollo astronaut Rusty Schweickart has formed the B612 Foundation. The organization's goal is to be able to significantly alter the orbit of an asteroid in a controlled manner by 2015.

"You can watch all of the golf on television you want, but if you want to go out and break par, it's going to take a lot of playing," Schweickart said. "And you're going to learn a lot that you thought you knew, but you didn't."

Congress directed NASA in December to look at expanding the search to asteroids larger than 140 meters (460 feet) in diameter and completing the new survey by 2020. Objects that size are capable of destroying a city.

"Space rock could make 2036 a killer year"
Michael Cabbag
14 May 2006
The Orlando Sentinel

Link: Orlando Sentinel

13 May 2006

French Idea to Hit Asteroid with Asteroid, Plus ESA ACT Calculates They Can Possibly Deflect Apophis using Small Spacecraft

Interesting article, so I have quoted several long sections below:

Various plans have been put forward to deflect incoming asteroids. For example, lasers or giant space mirrors could evaporate ices on their surfaces, creating jets that propel them away from Earth. And half-painting an asteroid could make it radiate heat differently on each side, slowly nudging the object off course.

But many of these plans require several years of advance warning in order to push the asteroids into safe orbits. If an asteroid or comet is found barrelling towards the planet with a year or less to impact, "that's a case where perhaps our only option is to attempt a big kinetic kill", says Durda.

Now, Didier Massonnet and Benoît Meyssignac of France's National Centre for Space Studies have come up with a new projectile to fire at the asteroid in such a "kill". They advocate capturing a small, 40-metre asteroid and "parking" it a stable Lagrange point 1.5 million kilometres from Earth, where the gravity of the Earth and the Sun balance.

If a larger asteroid were then found to be on a collision course with Earth, the small rock could be moved into its path within eight months, says the team. This "David's stone" would be too puny to cause any damage to Earth if things went awry, says the team. "Such an asteroid capture would be one of the most remarkable achievements of mankind," they write in Acta Astronautica.

But other experts say the plan is not realistic. It relies on using a small hopping robot to excavate rock at tens of metres per second from the little asteroid in order to provide the force to capture it and send it towards the larger rock. The capture would take a year of digging and would require the robot to remove 66% of the small rock's mass.

"To have a mechanical device work all on its own - without a person to kick it - in an essentially unknown surface environment full of dust and debris, is a very difficult thing to do technically," Durda told New Scientist.

Gerhard Hahn and Ekkehard Kührt of the German Aerospace Centre in Berlin agree. "It sounds rather like science-fiction," they told New Scientist in an email.

But Dario Izzo, an aerospace engineer at the European Space Agency's Advanced Concepts Team in The Netherlands, says the capture is technically feasible. "We can do it, but it would be really expensive," he told New Scientist.

Izzo is now working on a strategy based on ESA's plans for its Don Quijote mission. That mission is designed to put one spacecraft in orbit around an asteroid to watch as another is sent crashing into it. Don Quijote will be a technology demonstration mission, but Izzo's team has been working on ways to use just an impactor spacecraft to deflect a dangerous asteroid.

As a test case, the team used the orbital parameters of Apophis, a 400-metre-wide asteroid that will pass by Earth in 2029. During that pass, it may change course enough to hit Earth when it returns again in 2036 - a possibility that now has a one in 5000 chance of happening.

The team developed formulae to find out how much Apophis could be deflected by a 700 kilogram (1540 pound) spacecraft. "We found there are loads of trajectories, of launch windows, that would allow us to obtain a deflection," Izzo says. If a spacecraft were to launch by 2026, it could hit Apophis and change its speed by 0.01 millimetres per second – a tiny change, but enough to prevent it from colliding with Earth a decade later, he says.

"Taking out a killer asteroid – with a tame one"
Maggie McKee
26 April 2006

Link: Article

New Journal Article on Tsunami Risk from Asteroid Impact

"Tsunamis triggered by asteroid impacts cause a disaster similar to the 2004 Asian tsunami once every 6000 years on average, according to the first detailed analysis of their effects."

"For example, the model shows that waves radiating from the impact of a 300-metre-wide asteroid would carry 300 times more energy than the 2004 Asian tsunami. You can view movies of impact simulations in the North Atlantic, South Atlantic, Gulf of Mexico and Pacific (all in .mov format).

"The most common asteroids, between 100 m and 400 m, would yield tsunami waves up to 10 m when they arrived at the coast. A total of about 50 million coastal residents are vulnerable to such waves, though no single impact would affect them all. The researchers predict a tsunami-generating impact should occur about once every 6000 years, and would on average affect over one million people and cause $110 billion in property damage."

"The study also showed that asteroid impacts in the 300-metre class might be similar to the huge tsunamis thrown up when massive chunks of rock break from the sides of volcanoes and fall into the ocean. These events are also thought to occur roughly once every 6000 years."

"The analysis confirms suspicions that tsunamis are the biggest risk posed by asteroid impacts. The risks from climate effects of big impacts – through dust and smoke that blocks out the Sun – are about two-thirds that of tsunamis, while those of land impacts are about one-third of the tsunami risk."

"Tsunami risk of asteroid strikes revealed"
Jeff Hecht
12 May 2006

Link: Article

Natural Hazards
Publisher: Springer Netherlands
Issue: Volume 38, Number 3
Date: July 2006

Link: "Natural Hazards" Journal

Simulations of Impact
Steven N. Ward
Institute of Geophysics and Planetary Physics
University of California, Santa Cruz

Link: Simulations

12 May 2006

NASA Workshop on NEO Detection, Characterization and Threat Mitigation: Call for Papers

NASA Headquarters
NASA Research Announcement
Call For Papers: Near-Earth Object Detection, Characterization, and Threat Mitigation
Solicitation: NNH06ZAE001R

NASA is pleased to announce a Call for Papers for a workshop on Near-Earth Object (NEO) Detection, Characterization and Threat Mitigation to be held at a site to be announced. This workshop is being held in support of NASA's Office of Program Analysis & Evaluation (PA&E) study in response to congressional direction:

- Chartering NASA to detecting, tracking, cataloguing, and characterizing near-Earth objects in order to provide warning and mitigation of their potential hazard,

- Authorizing NASA to plan, develop, and implement a Near-Earth Object Survey program,

- And directing NASA to study possible alternatives to carry out the survey program and to divert an object on a likely collision course with Earth, and to report back to Congress with a recommendation on these alternatives recommended survey program.

Key Dates:
- Abstract submissions due May 26, 2006 by 11:59pm E.D.T.
- Author Invitation to attend workshop by June 7, 2006.
- White paper submissions (invitation only) due by June 25, 2006.
- Workshop location and dates to be determined (late June-July time frame).


Article on ISDC Presentation from Rusty Schweickart

“Remember, we’re dealing here with a less frequent, but far more devastating Katrina … a Katrina of the Cosmos,” Schweickart reported. “NEOs happen so infrequently that even though they are orders of magnitude more devastating, people don’t naturally make that match,” he told, “but you don’t want to be caught with your pants down.”

At present, the two asteroids on that “keep an eye on them roster” are 2004 VD17 and Apophis, formerly listed as 2004 MN4.

“Extrapolating to 2018 we may have as many as 200 in a similarly elevated attention category and of growing concern to the general public,” Schweickart reported today. “Therefore, it is certainly possible, if not likely, that in the timeframe of the next 12 years we—the world—may well be in a position where we need to take action to insure that we will be able to carry out a deflection mission if needed,” he said.

The Association of Space Explorers (ASE)—the professional organization of astronauts and cosmonauts—has formed a committee on NEOs which Schweickart chairs. Earlier this year, a technical presentation at a UN meeting in Vienna apprised them that this issue was coming at them.

While the UN has been brought the problem, Schweickart said, the ASE is committed to bringing them a solution. This solution will take the form of a draft United Nations treaty—or protocol—formulated in a series of workshops over the next two years.

“In these NEO Deflection Policy workshops we will gather together a dozen or so international experts in diplomacy, international law, insurance, and risk management, as well as space expertise to identify and wrestle with these difficult international issues,” Schweickart noted. “Our goal is to return to the UN in 2009 with a draft NEO Deflection Decision Protocol and present it to them for their consideration and deliberation.”

"Earth-Hitting Asteroids: Katrina From Space"
Leonard David
National Space Society
06 May 2006


03 May 2006

New Possible Object of Interest: 2006 HZ51

"A newly discovered asteroid is now the biggest thing known with a possibility of hitting the Earth in this century – and it is also the one that could hit the soonest."

"But the odds of impact currently stand at just one in six million, reducing the fear factor somewhat, and these odds should further diminish with additional observations. This latest addition to NASA-JPL's list of potentially hazardous asteroids was discovered on 27 April 2006."

"The asteroid, called 2006 HZ51, has an estimated diameter of about 800 metres and is the one of the largest objects ever to make the list. An object of that size would cause widespread devastation if it did strike the Earth."

"HZ51 also has one of the shortest lead-times to a potential impact of any such object yet found, and the shortest of any potential Earth-impactor currently on the list. The earliest of its 165 possible impact dates is just over two years away, on 21 June 2008."

"As for the newfound 2006 HZ51, the orbit calculations so far are based on just over 24 hours of observations, and so are likely to change quickly and should not be seen as a serious concern."

"Big new asteroid has slim chance of hitting Earth"
David Chandler
02 May 2006
New Scientist

Link: New Scientist Article

Link: JPL Near Earth Objects Page on 2006 HZ1

01 May 2006

Remember this Movie?: "Meteor" (1979)

I recently was reminded of this movie. Before the "Deep Impact" and "Armageddon" movies, came this cold-war based thriller/action movie. This movie had a very long cast list including Sean Connery, Natalie Wood, Karl Malden, Brian Keith, Martin Landau, Trevor Howard, Richard Dysart, and Henry Fonda (as the President of the United States, of course). Note: the actual movie premiere took place on the floor of Meteor Crater in Arizona.

From IMDB:

"After a collision with a comet, a nearly 8km wide piece of the asteroid "Orpheus" is heading towards Earth. If it will hit it will cause a incredible catastrophe which will probably extinguish mankind. To stop the meteor NASA wants to use the illegal nuclear weapon satellite "Hercules" but discovers soon that it doesn't have enough fire power. Their only chance to save the world is to join forces with the USSR who have also launched such an illegal satellite. But will both governments agree?"

Link: IMDB

Link: Wikipedia

Link: Amazon

Recent Article Reviewing Russian Thinking on Asteroid Mitigation

Recent article reviewing Russian mitigation efforts.

"Col. Gen. Vladimir Popovkin, commander of the Russian Military Space Forces, told a news conference Friday that the national satellite network lacked a spacecraft capable of preventing an asteroid strike...Russia established the Space Shield Foundation east of the Urals. The organization involved scientists from the Snezhinsk (Chelyabinsk-70) nuclear center and the Makeev State Rocket Center in Miass. The foundation eventually set up subsidiaries in Novosibirsk and Korolev, outside Moscow...The Planetary Defense Center, which was established in Russia three years ago, comprises the best defense-industry facilities, aerospace enterprises, in the first place, as well as academic and sectoral research."

"The Art of Asteroid Avoidance"
Based on a RIA Novosti release
Astrobiology Magazine
25 April 2006


Article that Reviews Recent Mitigation Options

An article that includes a review of recent mitigation options including ESA concepts, asteroid tractor, and projectile concept from Massonnet/Meyssignac in France.

"Now, Didier Massonnet and Benoît Meyssignac of France's National Centre for Space Studies have come up with a new projectile to fire at the asteroid in such a "kill". They advocate capturing a small, 40-metre asteroid and "parking" it a stable Lagrange point 1.5 million kilometres from Earth, where the gravity of the Earth and the Sun balance."

"If a larger asteroid were then found to be on a collision course with Earth, the small rock could be moved into its path within eight months, says the team. This "David's stone" would be too puny to cause any damage to Earth if things went awry, says the team. "Such an asteroid capture would be one of the most remarkable achievements of mankind," they write in Acta Astronautica."

"But other experts say the plan is not realistic. It relies on using a small hopping robot to excavate rock at tens of metres per second from the little asteroid in order to provide the force to capture it and send it towards the larger rock. The capture would take a year of digging and would require the robot to remove 66% of the small rock's mass."

"Taking out a killer asteroid – with a tame one"
Maggie McKee
26 April 2006


Proceedings of International Astronomical Union Symposia and Colloquia on Minor Bodies

"Asteroids, Comets, and Meteors (IAU S229) (Proceedings of the International Astronomical Union Symposia and Colloquia)"

By Daniela Lazzaro (Editor), Sylvio Ferraz-Mello (Editor), Julio A. Fernández (Editor), Karel A van der Hucht (Series Editor)
Publisher: Cambridge University Press (June 30, 2006)

"This is an up-to-date view of the solar system's minor bodies (comets, asteroids, meteors, trans-Neptunian objects and small satellites), stressing their interrelations, and relevance to accretion processes in the early solar system. The topics cover physical aspects, as well as dynamics, and observing programs related to these bodies. The volume also contains material related to current and planned space missions to minor bodies, in particular the successful Deep Impact mission to the comet Tempel 1. The book comprises 28 articles written by specialists in the field, who gave invited talks at the IAU S229 ACM meeting held in Búzios, Brazil, in August 2005. It will be of interest to researchers and graduate students working in planetary sciences and related fields."

Link: Cambridge University Press

Link: Amazon

25 April 2006

New Book on Comet/Asteroid Impacts and Human Reaction

New book on disasters and human reaction, specifically looking at human reaction to the threat.

"Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach"
Authors: Bobrowsky, Peter T.; Rickman, Hans (Eds.)
Publisher: Springer (May 2006)

"In 1908 an atmospheric explosion in northern Siberia released energy equivalent to 15 Mton of TNT. Can a comparable or larger NEO affect us again? When the next NEO strikes Earth will it be large enough to destroy a city? Will the climate change significantly? Can archaeology and anthropology provide insights into the expected cultural responses with NEO interactions? Does society have a true grasp of the actual risks involved? Is the Great Depression a good model for the economic collapse that could follow a NEO catastrophe? This volume provides a necessary link between various disciplines and comet/asteroid impacts."

Link: Springer Press

Link: Amazon

A Child's Guide to Asteroids Hitting the Earth (2 new books)

There are two new books aimed at younger readers about asteroids impacting the earth. One book is from Rosalind Mist is aimed at children between 9 and 11 years of age (grades 4 through 6). Another book from Peggy J. Parks is for even younger readers (ages between 4 and 8).

"Could an Asteroid Hit the Earth?: Asteroids, Comets, Meteors, and More" (from the Stargazers' Guides series)
Author: Rosalind Mist
Publisher: Heinemann (May 31, 2006)

"Could an asteroid hit Earth? The answer is 'yes'...and some already have! Craters here on Earth were made a long time ago by objects from space colliding with Earth. Could it happen again? Find out in this book. Detailed facts and photos help to answer your questions about the stars and beyond."

Link: Publisher


"Killer Asteroids"
(Kidhaven Science Library) (Library Binding)
Author: Peggy J. Parks
Publisher: Blackbirch Press (May 31, 2006)

"Earth is constantly bombarded by debris from space. Tons of ice fragments, dust, and meteorites fall from the sky every day, but most of the debris burns up in the atmosphere before it can cause any harm. Large asteroids are much less common -- but they are a deadly threat if they reach the ground. This book explains what asteroids are, how they form, and damage they have caused in the past -- including the scientific belief that a massive asteroid killed off the dinosaurs."

Link: Kidhaven Press

Link: Kidhaven Science Library

Link: Amazon

24 April 2006

ISDC 2006 Papers on NEOs and Planetary Defense

There will be a Near Earth Objects (NEO) session at the 25th Annual International Space Development Conference (ISDC) 2006 take will take place in Los Angeles, CA from May 4-7, 2006 (Sheraton Gateway Hotel). I will be chair for the (NEO) session.

- Multiple speakers will be at the overall meeting including:

Rusty Schweickart
Lunar module pilot for Apollo 9 and Chairman, B612 Foundation
Speaking Time: Luncheon Speaker - Saturday, May 6, 2006 at 12:00 pm (Century Room, Sheraton Gateway Hotel)

Don Yeomans
Senior Research Scientist, Supervisor for the Solar System Dynamics Group, and Manager of NASA's Near-Earth Object Program Office
Speaking Time: Small Bodies / Near Earth Objects (along with Andrew Westphal) - Saturday, May 6, 2006 at 11:00 am (Grand Salon, Sheraton Gateway Hotel)

- Session: Near Earth Objects
Chair: A.C. Charania
Date/Time: Sunday, May 7, 2006 from 9:00 am to 12:00 pm (Hermosa Room, Sheraton Gateway Hotel)

These are currently several papers in the NEO session:
- "A Process to Prioritize Mitigation Techniques Against Near Earth Objects" by A.C. Charania
- "Operational Spaceflight, NEO Resources, and Planetary Defense" by Edward Wright
- "Evaluate the Asteroid Threat" by Carlton L. Rhoades
- "Russia's Explorations of the Moon in the Seventies" by Boris Girshovich
- "Mitigate the Asteroid Threat" by Carlton L. Rhoades

Link: ISDC 2006

Link: ISDC 2006 NEO Panel (with abstracts)

15 April 2006

Asteroid Itokawa and the International Space Station (ISS) - to scale

Link: Spaceref - "How Big (Small) Things In Space Really Are"

July 3, 2006: Close Approach of Asteroid 2004 XP14 (Misses by 1.1 Lunar Distances)

There will be an upcoming close approach on July 3, 2006. Asteroid 2004 XP14 will miss the Earth by 1.1 LDs (lunar distances) at a velocity of about 17 km/s. It's diameter is estimated to be between 410 to 920 meters. Goldstone plans to make radar observations on July 3, 4, and 6, 2006 (they are requesting astrometry and physical observations).

Link: Orbit Diagram for 2004 XP14

Link: NEODyS information on 2004 XP14

Link: Goldstone Asteroid Observation Schedule

Arecibo Radar to Point Towards Asteroid Apophis in Early May 2006

From May 6-8, 2006 the Arecibo radio telescope will be obtaining data from asteroid 99942 Apophis. The next good observation window for Arecibo may be in January 2013.

From A/CC's minor object news:
"Arecibo is requesting photometry -- 'physical observations (lightcurves, colors, etc.)' -- to help prepare for radar observation on 6-8 May 2006. About astrometry, NEODyS notes that 'Only very accurate observations are useful' for risk analysis."

Link: Arecibo

Link: Radar Refinement of the Orbit of Asteroid 99942 Apophis (2004 MN4)

Link: Minor Object News

05 April 2006

Update from ESA Advanced Concepts Team on NEO Deflection Missions

"ESA commissioned a number of threat evaluation and mission studies through its General Studies Programme (GSP). In July 2004 the preliminary phase was completed when a panel of experts appointed by ESA recommended giving the Don Quijote asteroid-deflecting mission concept maximum priority for implementation.

Now it is time for industry to put forward their best design solutions for the mission. Following an invitation to tender and the subsequent evaluation process, three industrial teams have been awarded a contract to carry out the mission phase-A studies.:

- A team with Alcatel Alenia Space as prime contractor includes subcontractors and consultants from across Europe and Canada; Alcatel Alenia Space developed the Huygens Titan probe and is currently working on the ExoMars mission
- A consortium led by EADS Astrium, which includes Deimos Space from Spain and consultants from several European countries, brings their experience of working on the design of many successful ESA interplanetary missions such as Rosetta, Mars and Venus Express
- A team led by QinetiQ (UK), which includes companies and partners in Sweden and Belgium, draws on their expertise in mini and micro satellites including ESA’s SMART-1 and Proba projects

This month the three teams began work and a critical milestone will take place in October when the studies will be reviewed by ESA with the support of an international panel of experts. The results of this phase will be available next year."

"Asteroids: treasures of the past and a threat to the future"
Andrés Gálvez
Advanced Concepts and Studies Office
April 3, 2006


02 April 2006

Association of Space Explorers (ASE) and NEOs

The NEO Committee (basically led by Rusty Schweickart) of the Association of Space Explorers (organization of those people who have gone in space) has several documents related to the recent United States COPUOS meeting including the presentation given at the U.N. meeting, synopsis and actual paper behind the presentation. I have also included links to their previous open letter on NEOs and their Report to the Royal Aeronautical Society.

- ASE website

Link: The Association of Space Explorers (ASE)

Link: ASE Open Letter (PDF)

Link: Report to the Royal Aeronautical Society (PDF)

- COPUOS Reports

Link: Synopsis (MS WORD)

Link: Full Report (MS WORD)

Link: Presentation to COPUOS (PDF)

30 March 2006

Article on Asteroid Impacts and the Dinosaurs: Perhaps Two Impacts?

"Keller thinks dinosaurs survived the Chicxulub impact but were finished off by a larger, more catastrophic impact that happened roughly 300,000 years later. It was this later impact, Keller says, that is responsible for the K-T boundary."

"The views of Keller and her colleagues are controversial within the scientific community. Many scientists disagree with her team's interpretation of data...Recent work by other scientists, for example, has shown that fossil records could have been shuffled around by an enormous tsunami that would have followed such a significant asteroid impact. This would explain Keller's anomalous fossils, they argue."

"...Kyte dismisses the idea that an asteroid impact different from the one that occurred at Chicxulub was responsible for the dinosaur's mass extinction."

"Study stirs debate over dinosaurs’ fate" Some say evidence points away from Yucatan asteroid; others disagree"
Ker Than
30 March 2006


29 March 2006

SpaceWorks Engineering, Inc. (SEI) Becomes Sponser for 2007 Planetary Defense Conference

Atlanta-based engineering consulting firm SpaceWorks Engineering, Inc. (SEI) becomes the newest sponsor of the 2007 Planetary Defense Conference that will be taking place March 5-8, 2007 at George Washington University in Washington, D.C.

Link: Press Release

Link: 2007 Planetary Defense Conference

Activated Asteroids/ Main Belt Comets between Mars and Jupiter

"A bevy of the ice-containing bodies lies disguised as main-belt asteroids between Mars and Jupiter, claim astronomers from the University of Hawaii, US...David Jewitt and Henry Hsieh have dubbed the new population 'main belt comets'. They describe three objects with near circular, flat orbits in the asteroid belt that stream volatile materials, producing an observable tail for weeks and months at a time."

"The team believes in order to survive at such proximity to the Sun, the volatiles in the main belt comets would have to be covered by a layer of possibly carbonaceous material. They say an impact event could then uncover some of the volatiles, allowing the Sun's heat to trigger the observed outgassing."

"Clandestine comets found in main asteroid belt"
Kimm Groshong
23 March 2006


20 March 2006

Commentary on 2004 VD17, Risk Communication, and the "Purgatorio Ratio"

"Another impact scare, another risk communication mess. That is, in short, how one could sum up the latest developments in the saga of asteroid 2004 VD17."

"In the mean time, with nobody saying anything except that the Torino Scale value is two (and arguing about what this means, when it actually means nothing relevant at all), I fear that some NEO risk assessors have tied themselves into a knot."

"Thankfully, Brian Marsden has shed some light on these problems in his contribution further below. He also presents some new thoughts on the “Purgatorio Ratio”, an alternative NEO risk communication tool that aims to radically change the way information about asteroids with non-zero impact probabilities is assessed, organized, and communicated. I hope that the mess over 2004 VD17 will convince more members of the NEO community that the current risk communication system isn’t working properly and thus in urgent need of modification and improvement."

"a better—and more understandable—assessment of potential NEO hazards is provided by the ratio of the time interval spanned by the observations to the time remaining until the first possible impact date. For 2004 VD17 and the 2102 date, this “Purgatorio Ratio” (PR) is 0.014, increasing to 0.042 if one accepts the 2002 precovery observations and the 2102 threat continues to be valid. Even the 0.042 value is smaller than the PRs of 0.062 for (99942) Apophis in 2036 and 0.063 for (29075) 1950 DA in 2880. The next smaller values of PR are 0.022 for 2000 SG344 in 2068 and 0.011 for 2003 DW10 in 2046."

"Asteroid turns hot potato: when NEO risk communication becomes uncommunicative"
Benny Peiser
March 20, 2006


17 March 2006

Evidence of Possible 5km Diameter Object Impact in Antarctica

"Scientists say the evidence, if correct, points to a space rock some 5km across having crashed into the Ross Sea [Antarctica] about three million years ago."

"Researchers from the Lamont-Doherty Earth Observatory in New York have been studying a 100km-wide depression, known as Bowers Crater, under the Ross Sea."

"Space impact clue in Antarctica"
Paul Rincon
BBC News science reporter
Houston, Texas


Article on Asteroid Threat, Apophis, Etc.

"Schweickart and other scientists urged NASA to place a data-tracking radio transponder on the asteroid's surface by 2014."

"A transponder would help nail down orbital alterations caused by a phenomenon called the Yarkovsky effect. This is produced when an asteroid absorbs energy from the sun and re-radiates it back into space as heat. With one side of the asteroid lit and the other in darkness, the imbalance in thermal radiation produces a tiny acceleration. A transponder would help scientists understand how the Yarkovsky effect is influencing the asteroid's orbit."

"NASA responded to the urging with a wait-and-see proposal. 'We conclude a space mission based solely on any perceived collision hazard is not warranted at this time,' wrote Mary L. Cleave, associate administrator for NASA's science mission directorate."

"The agency believes continued optical and radio telescope observations will rule out Apophis as a threat. If not, NASA would launch a mission to the asteroid by 2018. A radio transponder, placed either in orbit or on its surface, would determine the asteroid's position in 2029 down to a few hundred feet, according to NASA."

"If an impact seems probable, a rocket would be launched to deflect the asteroid. The design phase would have to be completed by 2020 in order to launch by 2024, NASA noted."

"A 1-ton gravitational tractor could sufficiently divert Apophis outside the keyhole by hovering next to it for about a month, Lu and Love said."

"As scientists ponder that proposal, time marches on toward 2029 and 2036. Beginning this year, astronomers will lose visual and radar contact with Apophis, and the asteroid will not become visible again until 2013."

"Astronomers watch the skies for threat of deadly impact"
Bruce Lieberman
Paramus Post
March 17 2006


13 March 2006

2007 Planetary Defense Conference Website is Up

2007 Planetary Defense Conference
March 5-8, 2007
George Washington University
Washington, D.C.

"The objective of the conference is to develop a white paper that assesses the current state of our ability to discover and track near earth objects (NEOs—objects that could possibly impact Earth) and our ability to successfully deflect a threatening object should one be detected."


07 March 2006

Summary of Recent 43rd UN COPUOS Meeting: Related to Planetary Defense

The recent forty-third session of the Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space (COPUOS) was held from 20 February-3 March 2006 at the United Nations Office at Vienna, Vienna International Center, Vienna, Austria.

One of the agenda items was planetary defense. B612 Foundation Chairman Rusty Schweickart was there presenting on behalf of the Association of Space Explorers (ASE). Other presentations (see links below) included “Near-Earth objects related activities in the United Kingdom” by Mr. R. Crowther of the United Kingdom, “Near-Earth object research activities in the Republic of Korea: 2005 progress report” by Mr. Won-yong Han of the Republic of Korea, and “The need for an international near-Earth object committee” by Mr. A. MacDonald of the International Space University (ISU).

The UN press release stated the final agreement related to NEO defense as: "On near-Earth objects the Subcommittee stressed that early detection and precision of asteroids and meteors that may cross Earth’s orbit were the most effective tools for avoiding a collision, noting that any mitigating measures would require coordinated international efforts."

"Agenda of UN outer space panel: boosting medicine and averting cataclysm"
UN News Centre
March 6, 2006
Link: Press Release

Summary of 43rd UN COPUOS Scientific and Technical Subcommittee Session (February 20 - March 3, 2006)
Link: Session Reports

Presentations from the 43rd UN COPUOS Scientific and Technical Subcommittee Session Related to NEOs
Link: All Presentations

"NEO Deflection: An International Challenge"
R. Schweickart (ASE)
Link: Presentation PDF

"Near Earth objects related activities in the United Kingdom"
R. Crowther (United Kingdom)
Link: Presentation PDF

"Near-Earth object research activities in the Republic of Korea: 2005 progress report"
Wonyong Han (Republic of Korea)
Link: Presentation PDF

"The need for an international near-Earth object committee"
A. MacDonald (International Space University (ISU))
Link: Presentation PDF

06 March 2006

Roundup of Articles on Asteroid 2004 VD17

Various updates related to asteroid 2004 VD17 including specific object information and news articles:

2004 VD17 Impact Risk (from JPL)

2004 VD17 Orbital Information (from NEODys)

2004 VD17 Orbital Information (from Harvard)

2004 VD17 Wikipedia Link

Planetary Society Updates

Forums discussion

"New asteroid top of Earth's hit list"
Agençe France-Presse
March 3, 2006

"It's the end of the world"
The Sun (UK)
Paul Sutherland

"New Asteroid Becomes Earth's Biggest Threat"
Posted by Zonk
March 2, 2006

05 March 2006

Planetary Defense Conference in 2007

Following up on the AIAA Planetary Defense Conference in 2004, there will be a second AIAA Planetary Defense Conference in 2007. Tentative plans are for this second international conference to be held in Washington, D.C., on March 5-8, 2007.

Recommendations from a similar conference in 2004 can be
accessed at

A formal announcement from the AIAA should be anticipated soon.

03 March 2006

NASA Cancels Dawn Asteroid Mission: AP Article

NASA Cancels Mission to Visit 2 Asteroids
Associated Press
Thu Mar 2, 8:52 PM ET

"NASA on Thursday canceled a mission to visit two asteroids five months after the program was told to stand down because of cost overruns and technical problems."

"The project was capped at around $371 million, project scientists said previously. But the program was ordered to stand down after scientists asked for an additional $40 million last year."

"Dawn was supposed to lift off in June on a nine-year voyage to two of the solar system's largest asteroids, Ceres and Vesta, which reside in the main asteroid belt between Mars and Jupiter."

"The Dawn mission was put on standdown last October after going over budget and suffering several setbacks that included the rupture of two xenon fuel tanks during testing, forcing engineers to reduce the amount of xenon to be loaded in the tanks."


Update from David Morrison: Summary of Known Facts About 2004 VD17

Update from David Morrison at NASA Ames Research Center on 2004 VD17:

"At the end of February, orbital calculations for near-Earth-asteroid (NEA) 2004 VD17 indicated that the risk of an impact within the next century (specifically on May 4, 2102) was higher than that of any other known asteroid. The probability, based on 687 telescopic observations spanning 475 days, is listed on the JPL NEO Program webpage as a bit less than 1 in 1000."

"There is no similar keyhole in the case of VD17 [compared to Asteroid Apophis], although it does make relatively close passes by Earth in 2032, 2041 and 2067."

"...there are no near-term opportunities for additional observations, so VD17 will probably remain at Torino scale 2 for quite some time."


01 March 2006

Article on Asteroid 2004 VD17

"On 23 February, new observations allowed researchers to more accurately calculate the orbit of the asteroid, named 2004 VD17, which was originally detected by the Massachusetts Institute of Technology's LINEAR project. Since the improvement did not rule out a potential collision with the Earth on 4 May 2102, they increased the asteroid's rating to level 2 on the Torino Scale, a relatively rare event.

So VD17 currently claims the top spot on NASA's online list of potential asteroid impacts...Despite the rarity of the yellow designation, Yeomans says 'Torino 2 is not very alarming.' He notes that the scale does not take account of how soon an impact may occur, unlike its rival, the Palermo Scale...Based on current observations, he says the asteroid has a 1 in 1600 chance of striking the Earth in 2102 and a 1 in 500,000 chance of hitting two years later. But further observations will soon refine the orbit calculation for VD17 – and hopefully ease minds."

"New asteroid at top of Earth-threat list"
Kimm Groshong
March 1, 2006


28 February 2006

B612 Foundation's Preferred Mitigation Concept: Gravity Tractor

Here are some comments from B612 Foundation Chairman Russell Schweickart, it seems the gravity tractor is now their preferred mitigation concept (in place of the VASIMR plasma rocket with nuclear reactors):

- "Clearly the gravity tractor concept, with no new technology needed and no detailed knowledge needed re asteroid characteristics, can be accomplished in relatively short order, provided the money and motivation (or authorization, in the case of NASA) is available."

- "This mission, however, is far simpler than most Discovery class missions since it need carry virtually no scientific payloads, and Discovery missions fall in the $300M realm. At the moment we’re looking at what options for getting this mission underway make most sense."

- "Yes, the gravity tractor can be built and tested now, and by coincidence should we actually need an Apophis deflection (unlikely but possible) the gravity tractor is capable of doing the deflection job."

Link: Article

27 February 2006

Cumulative Impact Probability of Top 98 Near Earth Asteroids (as of Feb. 27, 2006) = 1 in 206 (with qualifications)

An interesting question related to the NEO threat is sa follows: "What is the actual risk of an object hitting the earth?" This should be a simple number the general public can easily understand. However, there are many qualifications experts want to include for such a number.

In response to that question, here is quick and dirty way to obtain a number representative of the risk using the most recent data.

I took Near Earth Asteroid (NEA) impact risk statistics for the top 98 NEAs from JPL (Source: updated February 27, 2006 and generated a cumulative impact probability for the top NEAs from this list.

So, taking the cumulative impact probability (if it is accurate now and in the future) for the top 98 NEAs from this list of this date, one obtains a chance of an impact of approximately 1 in 206.

Most of this risk comes from the top 10-20 objects in the 98 (ranked in terms of impact probability, from highest to lowest). This data should be coupled to potential damage since these objects are not all the same in composition and size. In addition, normally the chance of impact is lowered as more observations are made. As others have stated, it is the asteroid we do not know about that may most likely hit us.

Link: Recently Observed Objects Risk Scale from JPL

Article on European Space Agency’s Don Quijote Asteroid Deflection Mission

"Despite its playful name, taken from Miguel de Cervantes’s classic novel, the European Space Agency’s Don Quijote mission is deadly serious. Slated for 2012, the $180-million mission will attempt to move one of two target asteroids, just identified this fall, by rear-ending it with a speeding spacecraft. Quijote is the first venture of its kind, although the B612 Foundation, a privately-funded nonprofit based in Tiburon, California, intends to launch a similar effort by 2015."

"Rear-ending Rocks in Space"
Gregory Mone
Popular Science
January 2006

ESA's Don Quijote mission consiss of 2 spacecraft: one spacecraft (Hidalgo) will impact an asteroid of approximately 500 m diameter at a relative speed of at least 10 km/s, the other spacecraft (Sancho) will rendezvous and remain in orbit around the asteroid for several months before and after the impact. Public information indicates that the Don Quijote spacecraft set would have a total payload launch mass of around 1 MT. Public sources also indicate a launch using a Soyuz-Fregat launch vehicle (now most likely a Soyuz/ST launch vehicle that has a payload of 2 MT at a c3 = 0).

Link: Article

Updated Space Studies Insitute (SSI) Website Includes Asteroid Mitigation Section

The newly revised Space Studies Institute (SSI), founded by Dr. Gerard K. O’Neill, website includes section on asteroid deflection and mitigation.

Quotations include:

" For a long while, the conventional wisdom on this issue was that one would use nuclear explosives for this purpose. But according to a paper published in the June 4th, 1998 issue of Nature, this may not be as easy as previously thought. It points out that many asteroids are multi-lobed. A nuclear detonation might be largely absorbed by one lobe, with little course deflection resulting in the whole. The paper theorizes that the average asteroid may not be so much like a solid rock as an aggregate of fragments loosely held together by fine dust. If this “flying gravel pile” theory is correct, a nuclear detonation might pulverize an approaching asteroid, converting one big problem into many little ones...A mass driver engine, by contrast, could provide the low, steady, continuous thrust needed to change an asteroid’s course gradually, using the asteroid’s own material for reaction mass."

"Critical mass driver subsystems have been developed to technology readiness level 6 by SSI at Princeton University under contract NASA and private funding...A concept that has received relatively little attention in the literature is the employment of a mass driver to apply a steady acceleration to the asteroid which, given sufficient time, will develop lateral movements that can convert a strike on earth into a miss. The major advantage of this approach is that all the energy comes from the sun and all the reaction mass is obtained from the mass of the asteroid itself. The only mass that needs to be transported to the asteroid is that of the solar collectors, power supplies and acceleration coils which convert electrical energy to kinetic energy."

Link: Asteroid Deflection at SSI

Link: Asteroid Mitigation at SSI

Confirmation of Threat: 2004 VD17 Gets a Torino Rating of 2 (1 in 1,850 chance of hitting the Earth)

Object 2004 VD17 was given a Torino scale rating of 2, apparently only the second time in risk monitoring history this has happened. Thus currently only two objects have a Torino scale rating above 0: the well known 99942 Apophis (2004 MN4) and now 2004 VD17. However, whereas Apophis has close approaches within the next few decades, 2004 VD17 projections reveal close approaches in 2096, 2102, and 2104. 2004 VD17 has a 1 in 1,850 chance of hitting the Earth whereas Apophis has a 1 in 5,880 chance of Earth impact.

Here are some estimated parameters for 2004 VD17 from the most recent observations by JPL on Feb. 23, 2006:

Diameter: 0.580 km
Mass: 2.7e+11 kg
Torino Scale (maximum): 2
Palermo Scale (maximum): -0.40
Palermo Scale (cumulative): -0.40
Impact Probability (cumulative): 5.4e-04
Number of Potential Impacts: 4

Torino Scale 2 Definition: "A discovery, which may become routine with expanded searches, of an object making a somewhat close but not highly unusual pass near the Earth. While meriting attention by astronomers, there is no cause for public attention or public concern as an actual collision is very unlikely. New telescopic observations very likely will lead to re-assignment to Level 0."

- More detail from

Notes: 2004 VD17 was discovered by LINEAR on 7 Nov. 2004 and was announced the next day. It was posted with impact solutions at JPL and NEODyS on 9 Nov. when further observations became available. JPL elevated 2004 VD17 to Torino Scale 1 (a routine alert that an object "merits special monitoring") on 22 Nov., and NEODyS put it at TS-1 on the 23rd.

2004 VD17 had been noted to go out of view on 5 Feb. 2005 and wasn't observed after 28 Jan. until David Tholen's team picked it up from Mauna Kea on March 4th, which was published 13 days later.

On 15 Nov. 2005 it was reported that Tholen's team had recovered 2004 VD17 on the 4th, 11th, and 13th of that month using the University of Hawaii 2.2m telescope on Mauna Kea. This more than tripled the object's observation arc, from 117 to 371 days.

2004 VD17 brightened into view in early Feb. 2006 and was picked up with the Spacewatch 1.8m telescope on 6 Feb. It remains in view until around June 22nd, then comes back again in late July for the rest of the year. NEODyS notes "Very accurate observations necessary in March."

On 6 Feb. 2006, for only the second time in risk monitoring history, 2004 VD17 was raised to a Torino Scale rating of 2 (for "a somewhat close but not highly unusual pass near the Earth ... an actual collision is very unlikely"). JPL raised it to TS-2 after the next observation became available on Feb. 23rd.

Link Wikipedia Entry on 2004 WD17

Link: hohmanntransfer website

Link: 2004 VD17 Earth Impact Risk Summary from JPL

Link: Recently Observed Objects Risk Scale from JPL

26 February 2006

Image of Gravitational Tractor Concept by Dan Durda

Astronomy Picture of the Day: Gravitational Tractor
November 10, 2006

"How would you change the course of an Earth-threatening asteroid? One idea - a massive spacecraft that uses gravity as a towline - is illustrated in this dramatic artist's view of a gravitational tractor in action. In the hypothetical scenario worked out by Edward Lu and Stanley Love at NASA's Johnson Space Center, a 20 ton nuclear-electric spacecraft tows a 200 meter diameter asteroid by simply hovering near the asteroid. The spacecraft's ion drive thrusters are canted away from the surface. The steady thrust would gradually and predictably alter the course of the tug and asteroid, coupled by their mutual gravitational attraction. While it sounds like the stuff of science fiction, ion drives do power existing spacecraft and a gravitational tractor would work regardless of the asteroid's structure or surface properties."

Link: Astronomy Picture of the Day

Christian Science Monitor: Online Poll Results from 2005 on Apophis Mission

Poll results from the last year on a mission to asteroid Apophis.

- Question: "Should NASA launch a mission soon to tag the Apophis asteroid?"

- Result: Yes 78.27%, No 21.73% (out of 925 votes)

Link: Poll results

Link: Original Christian Science Monitor Article

"Pat Robertson Vaporized By Apophis Asteroid" and "Tom DeLay: Tax Cuts, Faith to Prevent Apophis Asteroid Collision"

I had noticed these "spoof" articles from last year using the asteroid Apophis. These fake articles are set in the future. Note: I post this for reference purposes only, making no political claims.

"Pat Robertson Vaporized By Apophis Asteroid"
Ion Zwitter
Avant News Editor
Avant News
November 15, 2005

Link: Article

"Tom DeLay: Tax Cuts, Faith to Prevent Apophis Asteroid Collision"
Ion Zwitter
Avant News Editor
Avant News
November 10, 2005

Link: Article

10 February 2006

ESA Advanced Concepts Meeting Paper on Asteroid Deflection

Dr. Roger Walker, Research Fellow over at European Space Agency (ESA) Advanced Concepts Team (ACT), has a presentation on asteroid deflection at the upcoming Workshop on Innovative Systems Concepts (21 February 2006) at the European Space Research and Technology Centre (ESTEC) in Noordwijk (The Netherlands). The presentation is entitled: "Advanced Solar and Nuclear Electric Propulsion Systems for Asteroid Deflection."

Link: Workshop

Link: Workshop Program

Link: ESA ACT mission analysis page on asteroid deflection

Link: ESA ACT paper on asteroid deflection

06 February 2006

United Nations Office for Outer Space Affairs Meeting (20 Feb. - 03 March) Considers NEO Threat

The forty-third session of the Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space will be held from 20 February - 03 March 2006 at the United Nation Office at Vienna, Vienna International Center, Vienna, Austria. This session will consider multiple issues including the NEO threat. I believe B612 Foundation Representatve Rusty Schweikert will be there.

The following is from the agenda (related to the NEO threat):

In paragraph 10 (b) of its resolution 60/99, the General Assembly endorsed the recommendation of the Committee that the Subcommittee, at its forty-third session, consider this item in accordance with the workplan adopted by the Subcommittee at its forty-first session (A/AC.105/823, annex II, para. 18) and amended at its forty-second session (A/AC.105/848, annex I, para. 20).

According to the workplan, the Subcommittee, at its forty-third session, would:

(a) Consider reports from Member States and international organizations on their near-Earth object activities, including missions, search and follow-up, as well as plans for future activity;
(b) Consider the need for a working group in 2007;
(c) Update the work programme for the third year as necessary and consider the need for intersessional work.

The reports mentioned in subparagraph (a) above will be contained in document A/AC.105/C.1/L.284.

Additionally, the Action Team on Near-Earth Objects will consider the way forward and, specifically, the possible need for further activity to be carried out nationally, regionally or through international cooperation. Such cooperation should be considered together with the prospects for harmonization and avenues for broader collaboration.

Link: Provisional agenda for the Forty-third Session of the Scientific and Technical Subcommittee 2006 (20 February-3 March 2005)

Link: United Nations Office for Outer Space Affairs

Article on Current Apophis Situation

"Can NASA learn enough about an approaching asteroid to rule out a collision in 2036?"
Bruce Lieberman
San Diego Union-Tribune
February 1, 2006

Link: Article

Planetary Society Funds for Asteroid Research

The Planetary Society is asking for funds related to two project: the Gene Shoemaker NEO Grant Fund anda new joint project to analyze asteroid threats with the B612 Foundation.

The Shoemaker Fund grants are to support asteroid tracking worldwide. The project with the B612 Foundation is to create a system of computerized "automated" maps that "will visually depict the specific narrow corridor across the face of the planet within which any given asteroid would strike."

Link: Release from the Planetary Society

Link: To support NEO research

30 January 2006

Asteroid Impact Mapping System from the Planetary Society

"The specific B612 project that we're hoping to support is aimed at filling part of the gap by creating a system of computerized "automated" maps that will visually depict the specific narrow corridor across the face of the planet within which any given asteroid would strike."


26 January 2006

Christian Science Monitor: Online Poll Results from 2005 on Apophis Mission

Poll results from the last year on a mission to asteroid Apophis.

- Question: "Should NASA launch a mission soon to tag the Apophis asteroid?"

- Result: Yes 78.27%, No 21.73% (out of 925 votes)

Link: Poll results

Link: Original Christian Science Monitor Article

12 January 2006

Rusty Schweickart Responds To Newspaper on NEO Article

“More data on asteroid”
Rutland Herald, Rutland, Vermont
January 11, 2006

With reference to Kendall Wild's Jan. 4 story "Doom from the Sky," I thought it important to correct a couple of understandable but significant errors.

Kendall stated correctly that the NEO "community" of astronomers and others saw a possibility of an asteroid (then 2004MN4, recently named Apophis) hitting Earth in 2029, but then goes on to say that after "some more fine-tuning of their computer data," they decided it wouldn't hit in 2029. This is a common misconception that needs to be corrected and better understood by the public. What changed the astronomers' minds was not fine-tuning existing data (implying that they didn't do a good job the first time) but rather additional (i.e., new) telescopic data. As you get more data the uncertainty in the orbit determination gets smaller and smaller. They didn't make errors. They continued (and still continue) to get more data.

He subsequently states that "in 2029 the asteroid will be closer to the earth than the moon is." True, but far more accurate and impressive is the fact that it will pass less than one-tenth the distance to the Moon — in fact closer to Earth than our communication satellites in geostationary orbit.

Overall, however, it is an excellent article on a subject of far greater importance than most people realize. Unreported (since it was not part of the conference on which Kendall reported) we can prevent impacts by near-Earth asteroids (see the Gravity Tractor, Nature, Nov. 7, 2005), and this capability should be demonstrated before we need to use it. The real question is, will we?

Rusty Schweickart
(Chairman, B612 Foundation)
Tiburon, Calif.


05 January 2006

Radio Show: "Asteroid Apophis due to pass close in 2029"

"Asteroid Apophis due to pass close in 2029"
Program #4,758 of the Earth & Sky Radio Series
Hosts Deborah Byrd and Joel Block
January 13, 2006

"If that object passes through a 600-meter-sized keyhole in 2029, that is, a location in space that is only 600 meters wide, it will indeed hit the Earth in 2036. But the chances of its actually passing through this 600-meter-sized keyhole in space in 2029 are extremely low."

Link (including mp3 link)

Interview with Don Yeomans on NEOs, Mitigation, and Apophis

"...that object [Apophis] is of concern. Not in 2029, when it makes its close approach, but -- once you do have a close approach like that, it makes computing the subsequent orbital position of that object more difficult. So, if that object passes through a 600 meter sized keyhole, in 2029, that is, a location in space that is only 600 meters wide, if it passes through that, it will indeed hit the Earth in 2036. Now the chances of it actually passing through this 600 meter sized keyhole in 2029 is extremely low, and we'll know whether it will or won't probably next year when we get additional radar data in May of 2006. And if we can't rule it our then, there's an additional radar opportunity in 2013 that will almost certainly rule out this possibility. In the unlikely possibility that we don't rule it out in 2013, there's still time to mount a mission to deal with it. This object illustrates the point rather well. It was discovered early, so we have lots of options. The first is to wait until 2013, when this whole thing will almost certainly go away."


Radio Show: "How likely is a killer asteroid?"

Program #4,750 of the Earth & Sky Radio Series
Hosts Deborah Byrd and Joel Block
January 5, 2006

"Although it is classified as potentially hazardous and about 300 meters in size, Apophis doesn't appear to be any threat on its passage in 2029. It's just a great photo opportunity for astronomers."

Link (including mp3 link)

Table of Potentially Hazardous Asteroids (PHAs)

"The following table lists the predicted encounters by Potentially Hazardous Asteroids (PHAs) to within 0.05 AU of the earth from the start of this year through 2178."


Reference to Laser Ablation Mitigation of NEOs

The Journal of the Astronautical Sciences by the American Astronautical Society (AAS).

Park, S.-Y.; and Mazanek, D.D.; "Deflection of Earth-Crossing Asteroids/Comets Using Rendezvous Spacecraft and Laser Ablation," Journal of the Astronautical Sciences, pp. 21-37, Vol. 53, No. 1, Jan-Mar 2005.

The Psychological Reaction to NEOs

"Reacting to Disaster"
By Doug Vakoch
Director of Interstellar Message Composition, SETI Institute

"But if natural human reactions to threats interfere, the ending could be far from uplifting. If fear and denial postpone an adequate response, dust and debris could make the daytime sky look like night, the Earth’s surface could be razed by a global firestorm, and tsunamis could obliterate coastal cities."

"...we need to be aware of our tendency to latch quickly onto one answer, even when subsequent information calls it into question. To guard against such uncritical acceptance of one position, some key decision makers may be selected to play the role of devil’s advocate. By sanctioning the role of dissident, unpopular but potentially vital alternatives can be explored, providing one safeguard against monolithic 'groupthink.'"


03 January 2006

30 December 2005: News Updates from NASA Ames (David Morrison)

"A variety of recent news releases on the impact hazard (covering Apophis, the Gravity Tractor, Itokawa, Pan-STARRS, and the House Authorization of advanced surveys)"


Relevant Paper on Apophis and Upcoming Detection Opportunities

Paper: "Potential Impact Detection for Near-Earth Asteroids: The Case of 99942 Apophis (2004 MN)" by Steven R. Chesley of the Jet Propulsion Laboratory (JPL)

Link: PDF of paper (From B612 Foundation site)

Impact Explosion on the Moon

"NASA scientists have witnessed a rare explosion on the Moon, caused by a 'meteoroid' slamming into it."

Link: BBC News article
Note: Any opinions expressed on the blog are solely those of the author. The site is not sponsored by, nor does it represent the opinions of, any organization, corporation, or other entity.