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.

29 March 2007

Interesting YouTube Video of Japanese Hayabusa Mission

Interesting video detailing Japanese Hayabusa mission to Asteroid Itokawa.

"Asteroid Adventure - The Hayabusa Mission"

Link: YouTube Video

Article: "Amateur and Professional Astronomers Cooperate to Map Dancing Asteroid"

Selections from the article:

The motions of an asteroid with two whirling parts are now better known, thanks to a rare collaboration between professional and amateur astronomers.

Called 90 Antiope, the asteroid consists of two egg-shaped rubble piles locked in orbit, like two twirling dancers facing one another with linked arms. Antiope is thought to be the remnants of a larger asteroid, dubbed Themis, which astronomers think was destroyed by an impact with another asteroid some 2.5 million years ago.

The finding is detailed in the April 2007 issue of the scientific journal Icarus.

Using the 10-meter Keck II telescope in Hawaii, astronomers discovered in 2000 that Antiope, once thought to be a typical asteroid floating between the orbits of Mars and Jupiter, actually consists of two gravitationally linked space rocks.

Subsequent observations by Keck II and the Very Large Telescope in Chile determined the orbits of Antiope’s two parts, each of which were found to be about 53 miles (86 km) in diameter and separated by about 106 miles (171 km).

“Amateurs can be used for professional studies, compensating for the small size of their telescopes by the large number of observations and the frequency of observations they can do,” said study team member Franck Marchis, an astronomer at the University of California, Berkeley.

"Amateur and Professional Astronomers Cooperate to Map Dancing Asteroid"
Ker Than
Staff Writer
29 March 2007

Link: Article on

28 March 2007

Article: "That asteroid theory is only partly right"

Selections from the article...

The first bit of the story [asteroid impact 65 million years ago], about the dinosaurs, is still right. But a new 10-year study tracing the family history of almost all the 4500 species of mammals alive today provides a very different picture of what happened before and just after the asteroid hit.

It shows that the ancestors of most modern groups of mammals, including apes, rats and hoofed animals, began to emerge earlier than thought, as long as 80 million to 100 million years ago.

While they existed when the dinosaurs roamed the Earth, and survived the asteroid impact, their numbers and variety were low.

After the demise of the dinosaurs, there was a small group of mammals that immediately benefitted. But those that flourished 65 million years ago, including an aggressive wolf-like cow, were not closely related to today's species and eventually died out.

It wasn't until about 15 million years after the dinosaurs were gone that the ancestors of modern mammals came into their heyday, and exploded into the diverse array of species we now know.

"That asteroid theory is only partly right"
March 29, 2007
Sydney Morning Herald

Link: Sydney Morning Herald Article

Former Clinton Cabinet Secretary Robert Reich on Budget Priorities and NASA NEO Protection

Interesting viewpoints...from the article...

All of which raises at least three pertinent questions...First, if we're spending over a billion dollars a day in Iraq, why can't we bring the troops home a few days earlier and use the savings to track killer asteroids that might end life on Earth?

And since we're talking about the survival of most living things and not just Americans, why shouldn't we expect other nations to kick in some money, too — especially now that the dollar is dropping relative to the euro and the yen?

And third, once NASA knows for sure that a killer asteroid is heading directly for us, how exactly are we supposed to get ourselves out of its way, or it out of our way — and how much should we be budgeting to accomplish this?

"Budget dodges killer asteroids"
Robert Reich
28 March 2007

Link: Marketplace Radio Article

Link: Listen to Commentary

Asteroid 2006 VV2 Near Earth in March/April 2007

From the article:

Asteroid 2006 VV2 will be passing close to the Earth at the end of March and in the early part of April 2007, just a few days away.

Its closest approach is on March 31st where it will be just under nine times the distance between the Moon and the Earth, about 3.4 million kilometers. The Earth and Moon are about 385,000 kilometers (240,000 miles) apart.

Observers should be able to see it through small telescopes as it becomes a 10th magnitude asteroid while racing across the sky through the constellation Leo between March 31st and April 1st. Asteroids are also called minor planets or planetoids--that is, a rock that drifts in space as it orbits around the Sun.

The asteroid is estimated to be about two kilometers (1.2 miles) in diameter. There’s a small chance that it may consist of two asteroids, or a binary system.

Asteroid 2006 VV2 was discovered by the LINEAR program from the Massachusetts Institute of Technology (MIT) on November 11, 2006, at White Sands Missile Range in Socorro, New Mexico. Due to its close approach to the Earth, 2006 VV2 is classified as a “Potentially Hazardous Asteroid” by the Minor Planet Center.

The home Web page of the Minor Planet Center is:

Additional information about Asteroid 2006 VV2 is found at:

NASA Jet Propulsion Laboratory:

Harvard University:

"Asteroid 2006 VV2 is coming for a visit"
William Atkins
29 March 2007

Link: Article on ITWire

27 March 2007

How Stuff Works: Is Earth on a collision path with a major asteroid?

"At the moment, though, the method of choice for saving Earth from Apophis is deflection...There are a few big ideas out there. One has several spacecraft landing on Apophis, drilling through the surface and pumping out what's inside. NASA has actually done something like this successfully with its Deep Impact mission, which crashed an impactor into a comet with the purpose of revealing the comet's composition. With Apophis, the point would be to pump the material out into space with enough force to push Apophis in the opposite direction, throwing it off course. Scientists are also talking about sending a spacecraft into the asteroid's orbit to fly next to it. This "gravity tractor" spaceship would essentially alter the gravity equation that keeps Apophis on its path, pulling on the asteroid until its position no longer threatens Earth...But according to Donald Yeomans of NASA's Near Earth Object Project, the simplest way to deflect Apophis is to send a spacecraft up there to just slam into it, knocking it out of the way."

Link: How Stuff Works - Apophis

NIck Bailey's Poor Experience at the 2007 Planetary Defense Conference

The author of the research mentioned in a recent post here, Nick Bailey, has his own blog and photoblog. Here is an excerpt from his photoblog on the 2007 PD Conference. I do not agree with his observations about America in general but I find his comments on the reaction to newbie researchers in the field of planetary defense to be generally accurate. The small group of "planetary defense" experts at the 2007 Planetary Defense Conference definitely reminded me of high school. If you were not in the right "clique" [informal and restricted social group] then members of the audience had much less hesitation in confronting a presenter. I would encourage scientific debate but perhaps at the conference it was not evenly vigorous for all presenters.

08 March 2007
Last Minute Planetary Defence

So the conference today was a bit of an experience. Preferably one not to repeat again. Quite frankly it near enough put me off continuing in my field of research.

I arrived for breakfast with a pretty bad headache and the organiser asked if I'd be able to expand my poster presentation (2 minutes) up to a full 20 minute + 10 mins of questions job. Like I could refuse. Knowing it's all for the good of my research I agreed and then proceeded to spend the whole morning sessions writing an entirely new presentation. All the talks today were totally related to my work and I could really have done with giving it my full attention. Throughout this my headache didn't abate and rather got worse. In fact I know realise it was a migraine as I threw up in the toilet three times before lunch (one of which I didn't quite make it to the basin). Unlike a standard sickness this didn't make me feel any better so after finishing the slides (not having eaten any lunch) I found a sofa outside the conference room to take a nap in waking up just before I was due onstage.

By now I was feeling more stable and not sick but the head was nicely pounding. With a few prayers sent ahead I got onto the platform and begun, actually feeling quite clear while I was up there. I also felt I spoke reasonable clearly with only a few problems of not knowing what was on the slides (as I'd hardly seen them myself). Having not prepared anything I wasn't clear enough in introducing the actual results, so when I got to them I was immediately interrupted with a question from the floor. Then another. And I think there might have been a third. They pointed out that my results were void as the object I had simulated impacting should never have made it through the atmosphere (according to the research presented earlier in the day). This helped enormously as you can expect. But I think I answered their questions and continued onto the rest of the results and reached the end of the 20 minutes (surprisingly - I was expecting to fall short).

Then the questions started. Quite frankly I can't remember what was said but the first question was valid and all the others simply laid into me tearing my research to pieces. By the time I escaped the podium I was just about in tears and spent the next hour holding them back and hoping nobody would come and talk to me as that would have tipped me over the edge - especially if anyone had offered me any encouragement.

So that was all a bit shit and as I said it's totally destroyed any interest in me continuing in this research. I'd take a years postdoc if offered but only as a filler.

The ironic thing is that the final talk (and some other points made previously) highlighted how damn old the people in this field are and how they need to attract new people. The final presented said something to the effect that it's too insular and very hard for newbies to break through and present their work. I agreed and would quite definitely favour moving to the world of climate change as that is something I care far more deeply about.

So tomorrow I'll have to show my face again (though i might have a shave - I think this was one of my biggest mistakes, I should have shaved before to make myself look younger and less knowledgeable) and see if I can extract the wreckage of my research and dignity from the feasted remains. I'll also try hard not to get angry at one of the old gits who was quite horrid today.

Link: Nick Baileys' Blog

Link: Nick Baileys' PhotoBlog

IAF Focus: Near Earth Objects

The International Astronautical Federation (IAF) has a focused article on Near Earth Objects (NEOs). Also included in the article is an interview with Professor Roger Bonnet, President of COSPAR. From the article:

NEOS were given special attention in 2007. In February 2007, the Association of Space Explorers presented a paper to the Scientific and Technical Subcommittee at 42nd session of the Committee on the Peaceful Uses of Outer Space (COPUOS).

From that paper came an initiative which has set up a series of meetings of experts and other interested people which will explore the subject of NEOs and possible means of diverting these objects from Earth before they would hit.

The experts will draft a Treaty that should be presented to the UN General Assembly in 2009.

The IAF has interviewed Dr Roger Bonnet on his involvement in this initative.

Link: IAF Focus Page on NEOs

Research on Global Asteroid Impact Damage

"Simulations show the asteroid impact locations that would produce the most casualties in red. The Pacific coast of Asia is a particularly deadly place for an asteroid to strike because of tsunamis, while a direct strike on some densely populated inland areas could also cause a heavy toll (Illustration: Nick Bailey et al/University of Southampton)"

Continued...from the article...

Now, researchers have combined impact effects with data on population density and infrastructure location in a computer model to produce the first global ranking of countries based on their vulnerability to impact damage.

Nick Bailey of the University of Southampton, UK, led the development of the new software. The team used the model to simulate thousands of impacts at points all over the Earth, building up statistics on which countries tended to be the worst affected the most often.

They considered a range of impact energies corresponding to asteroids between 100 and 500 metres across, striking with typical solar system speeds of about 20,000 kilometres per second.

The researchers also produced maps showing the worst possible places on Earth for an impact to occur. The Pacific coast of Asia shows up as an especially bad place in terms of producing casualties. Impacts in the north Atlantic Ocean, which can send tsunamis to both Europe and North America, tend to produce particularly high infrastructure losses.

The biggest source of uncertainty for the results is the possibility that a single incoming asteroid might not make it to the ground intact, fragmenting in the atmosphere instead to produce multiple, smaller impacts – a scenario not considered in the model, Bailey says.

Clark Chapman of the Southwest Research Institute in Boulder, Colorado, says more research along these lines is needed to better understand the nature of the asteroid hazard. "We need to understand the potential risks on a country-by-country basis, since individual countries may have different vulnerabilities to this hazard as well as different capabilities to deal with it," he told New Scientist.

"China and US at highest risk of damage from asteroids"
David Shiga
27 March 2007

Link: New Scientist Article

Link: Press Release from School of Engineering Sciences, University of Southampton

Note: Apparently the author of this research, Nick Bailey, has his own blog and photoblog. My next post will have an excerpt from this blog on the 2007 PD Conference.

Link: Nick Baileys' Blog

Link: Nick Bailey's PhotoBlog

26 March 2007

Various Online Asteroid Videos

- Empire Strikes Back Asteroid Field

Link: YouTube

- Earth's Destruction - Asteroid

The History Chanel listed the top 10 reasons the Earth could be destroyed. Counting down from 10, an asteroid was #4.

Link: YouTube

- KT Asteroid Impact

Visualization of asteroid impact that killed dinosaurs 65 million years ago, based on accurate research and scientific fact. Created by Radek Michalik at the Science Institute of Columbia College Chicago

Link: Google Video

- Rusty Schweickart, The Asteroid Threat Over the Next 100,000 Years (The Long Now Foundation)

Link: Google Video

- Rusty Schweickart, "An asteroid will hit earth in 2029"

Link: Google Video

Article on Difficulty of Finding Appropriate Asteroids for Human Missions

"Asteroid missions: be patient, or bring lotsa gas"
Tom Hill
26 March 2007

Link: Article on

Link: Longer Version of Article

25 March 2007

Article on Arecibo and Funding Issues

Selections from the article follow:

The prospect of closing a telescope able to spot a basketball-size object 100 light years away comes at a time when leading scientists searching the heavens have discovered a major asteroid that has a 1 in 45,000 chance of striking Earth in 2036.

Wayne Van Citters, the National Science Foundation's division director for astronomy, said a decision to limit Arecibo's funding to $6 million by 2011 was made on the advice of a review committee. The annual budget is now $12.5 million.

If the observatory can't make ends meet via other avenues of support, then closure is a possibility, he added.

"We undertook this process to determine how we might change the balance [in funding] or close down certain facilities in order to move into the future," Van Citters explained.

Seeking international funding is one idea that has gained traction to lessen National Science Foundation cuts, Arecibo officials said. The idea of selling advertising on the telescope's dish has even been discussed.

The "dish" is 1,000 feet in diameter, 167 feet deep, and covers an area of about 20 acres. The surface is made of almost 40,000 perforated aluminum panels, each measuring about 3 feet by 6 feet, supported by steel cables strung across an underlying sinkhole.

Suspended 450 feet above the reflector is the 900-ton platform that hangs in midair on 18 cables strung from three reinforced concrete towers.

Arecibo is one of two places in the world where radar astronomy is effectively performed, officials said. The other is the 230-foot wide Goldstone antenna in California's Mojave Desert. While the Arecibo radar cannot be steered like Goldstone, Puerto Rico's observatory is said to be 30 times more sensitive in detecting returning signals.

Link: Article

22 March 2007

Alan Boyle Reviews Rusty's Paper and the NASA NEO AoA Report

The entry on Cosmic Log also refers to Astronomer Dave Tholen (at the University of Hawaii's Institute for Astronomy) who has some new data for Apophis. This should update the current impact risk of 1 in 45,000 for ApophiosThis data was mentioned at the recent 2007 Planetary Defense Conference. Quote from Don Yeomans: "He's so good that it's well worth waiting for."

"Dueling Over Asteroids"
Alan Boyle
21 March 2007

Link: Cosmic Log

21 March 2007

Rusty's AAOA (and NEO Size-Frequency Diagram by Alan Harris)

Here is Rusty's Alternative Analysis of Alternatives from the B612 Foundation website. I also show below the size-frequency diagram for near-Earth objects by Alan Harris that is in Rusty's report.

Size-frequency diagram for near-Earth objects, courtesy Alan Harris. The superposed intersecting lines bound the 99% of NEO impacts most likely to be encountered and trigger a call for deflection. These NEOs range from 45 – 400 meters in diameter. The left vertical line reflects the most recent estimate of the impact energy (5 MT) associated with the Tunguska event in 1908.

Link: B612 Foundation Latest News Page

Link: Letter to NASA Administrator Mike Griffin

Link: Rusty's Alternative Analysis of Alternatives

20 March 2007

Leonard David on Rusty's Alternative Analysis of Alternatives (and on getting the full NEO AoA report)

Leonard David (, LiveScience) also talks about Rusty's Alternative Analysis of Alternatives, from Leonard's blog on LiveScience...

"NASA’s Congressionally-requested report on asteroids — and what to do about worrisome, Earth-smacking space rocks — is in the cross-hairs of former Apollo astronaut, Russell Schweickart.

For one, the study spotlighted use of nuclear standoff explosions to divert a potentially hazardous object, suggesting that such a technique is 10-100 times more effective than the non-nuclear alternatives analyzed by NASA study officials.

That conclusion has been flagged by an asteroid expert as one of the greatest stupidities in the report.

Meanwhile, Schweickart has launched his own report deflection campaign, requesting NASA chief, Mike Griffin, to support open discussion and examination of the report’s findings. Schweickart is mounting an effort to bring out basic issues either not considered or ignored in the NASA report to Congress.

“Outsiders” to the NASA study — Near Earth Object Survey and Deflection Analysis of Alternatives — have been denied access to the larger, over 270-page “limited edition” of the final report. That makes it essentially impossible to know, let alone critique, the sources used to prop up the NASA report conclusions, Schweickart says."

Link: LiveScience Blog on Rusty's Analysis

Rusty's Open Letter (and his Alternative Analysis of Alternatives) to NASA Administraor Mike Griffin: JUXTAPOSITION with the NASA Congressional Report

Rusty Schweickart has written an open letter to NASA Administrator Michael Griffin that discusses the recent NASA NEO Analysis of Alternatives (AoA) report.

Beyond the issues addressed by Rusty in his commentary I agree with some of his issues on the release of the full 200+ page NASA NEO AoA report. If the U.S. Congress can see this unclassified report about the government's response to the threat from a potentially large natural disaster but the public cannot, I have some issue with that. I would urge those in the know including Lindley Johnson (NASA NEO program office), Bill Claybaugh (lead person at NASA PA&E involved with the study as far as I can tell), and of course NASA Administrator Mike Griffin to release the full study. I would not want this to turn out like NASA's Exploration Systems Architecture Study (ESAS), where we got a very large report but were missing some very interesting and relevant appendices.

On to some of my initial comments on Rusty's paper.

To me it seems like this retort by Rusty was in the making before the NASA NEO AoA report was released. I need to be convinced of the estimates he make of the gravity tractor. Several people have told me that designing the spacecraft is not the main problem, hand-waving the issue in essence. Yes the design of a gravity tractor spacecraft could potentially be simple, but at this point, with all the talk of the gravity tractor in the media, I think we need a conceptual design with mission analysis, mass breakdown, power budget, operations plans, and life cycle cost assessments. The papers out there talk about the simple gravitational equations that initially describe the problem (though Eugene Fahnestock, a PhD student under Danial Scheeres at the Univ. of Michigan did present an very interesting gravity tractor dynamical analysis at the recent 2007 Planetary Defense Conference).

I believe Rusty's criticisms may be spurred from some of the slides presented at the 2007 Planetary Defense Conference from the NASA NEO AoA study. Some of these slides had results that are not in the report that was publicly released. This data on these slides did show large costs for various mitigation options including the gravity tractor.

He states that he has conducted a "parallel analysis of the various alternatives for diverting a threatening NEO to that which NASA submitted to the Congress. In it I [Rusty] provide the basic logic and resultant conclusions and then juxtapose them with the NASA response commenting on why the apparent difference."

In this letter, Rusty (representing only himself and not the B612 Foundation or Association of Space Explorers) brings up the concept he discussed at the recent 2007 Planetary Defense Conference, namely a gravity tractor combination mitigation approach coupled with either a kinetic impactor or nuclear option. As he states: "The characteristics of the gravity tractor and kinetic impactor are such that they nicely compensate for each others' limitations." He also states: "Consideration should be given in the future to flight testing the kinetic impactor/gravity tractor combination to validate the capability and provide confidence to the world public."

Later on, Rusty states that he has issues with the perceived cost estimates in the report (since we do not have the full report). In commenting on this issue, he discusses the cost of the Gravity Tractor (or GT): "The GT concept, as presented in NASA's NEO Workshop held in Vail, Colorado in June-July 2006, is adaptable to any size spacecraft and was specifically presented and evaluated in White Paper 42 (the only professional paper presented on the gravity tractor) based on NASA's Deep Space 1 spacecraft flown successfully from 1998-2000 and costing (based on the official NASA website, $149.7 million (FY 95-99). Given that the presentations at NASA's Vail Workshop explicitly presented and evaluated the GT concept based on the Deep Space 1 mission technology, and not on the cancelled Prom"etheus, it is mystifying why, in NASA's Report to Congress the GT was presented as technically immature and extremely costly. Without access to the Final Report it cannot be stated with certainty but it appears that NASA inappropriately used the low technological readiness level and extreme cost of the cancelled Prometheus spacecraft as a proxy for the GT. In this analysis I use the GT as it was presented to the NASA study team in the NASA NEO workshop in Vail, Colorado."

Another issue he addresses is resonant returns or keyholes, and the potential failure of the NASA NEO AoA report to examine this aspect of mitigation missions.

Independent Analysis of Alternatives To Divert a NEO on a Likely Collision Course With Earth
19 March 2007
Source: Russell L. Schweickart

Link: Rusty Schweickart's Letter and Limited Analysis (Source: SpaceRef)

19 March 2007

SpaceDaily Article on NASA NEO AoA Report

This article is a basic survey of the NASA Near Earth Object (NEO) Analysis of Alternatives (AoA) report.

"Near-Earth Object Survey And Definition Analysis Of Alternatives Report To Congress"
Staff Writers
Washington D.C.
19 March 2007

Link: Article

Update on Wiki Entry for "Planetary Defense"

I have updated the Wikipedia entry for the term "Planetary Defense." Look for more updates on Wikipedia entries.

Link: Planetary Defense (from Wikipedia)

Jeff Foust (Space Review) Article on Planetary Defense

"Detection, Deflection, Decision-making"

"The three D’s of planetary defense"
Jeff Foust
19 March 2007

Link: Article

16 March 2007

NASA's Current Discovery Class of Spacecraft and More on the OSIRIS Mission (Sample Return from a NEO)

The Discovery class of missions are smaller spacecraft programs (under ~US$500M total cost) at NASA. There are competitive selections. The current round has several interesting NEO missions (a down-select will occur sometime in 2007).

Selections from NASA press releases [and more about the OSIRIS mission concept]...

NASA may select one or more investigations to continue into a development effort after detailed review of the concept studies. Decisions about which mission concepts will proceed to development are expected next year...New missions will receive $1.2 million to conduct concept studies. If selected for continuation beyond the concept phase, each project must complete its mission, including archiving and analyzing data, for less than $425 million....Missions of opportunities will receive $250,000 to conduct concept studies. If selected for continuation, each mission of opportunity must complete its project, including data archive and analysis, for less than $35 million.

Three missions were selected for concept studies:

-- The Origins Spectral Interpretation, Resource Identification and Security (OSIRIS) mission would survey an asteroid and provide the first return of asteroid surface material samples to Earth. Michael Drake of the University of Arizona, Tucson, is OSIRIS's principal investigator. NASA's Goddard Space Flight Center, Greenbelt, Md., would manage the project.

-- The Vesper mission is a Venus chemistry and dynamics orbiter that would advance our knowledge of the planet's atmospheric composition and dynamics. Gordon Chin of Goddard is Vesper's principal investigator. Goddard would manage the project.

-- The Gravity Recovery and Interior Laboratory (GRAIL) mission would use high-quality gravity field mapping of the moon to determine the moon's interior structure. Maria Zuber of the Massachusetts Institute of Technology, Cambridge, Mass., is GRAIL's principal investigator. NASA's Jet Propulsion Laboratory, Pasadena, Calif., would manage the project.

The three missions of opportunity selected for concept studies are:

-- The Deep Impact eXtended Investigation of Comets (DIXI) mission would use the existing Deep Impact spacecraft for an extended flyby mission to a second comet to take pictures of its nucleus to increase our understanding of the diversity of comets. Michael A'Hearn of the University of Maryland, College Park, Md., is DIXI's principal investigator.

-- The Extrasolar Planet Observations and Characterization (EPOCh) mission would use the high-resolution camera on the Deep Impact spacecraft to search for the first Earth-sized planets detected around other stars. L. Drake Deming of Goddard is EPOCh's principal investigator.

-- The Stardust NExT mission would use the existing Stardust spacecraft to flyby comet Tempel 1 and observe changes since the Deep Impact mission visited it in 2005. In 2005, Tempel 1 has made its closest approach to the sun, possibly changing the surface of the comet. Joseph Veverka of Cornell University, Ithaca, N.Y., is NExT's principal investigator.

"NASA Announces Discovery Program Selections"
30 October 2006

Link: NASA Press Release on Discovery Missions Proposals


A menacing lump of rock and dust in space called 101955 (1999 RQ36) would barely be noticed except for two crucial facts: First, "It's a treasure trove of organic material, so it holds clues to how Earth formed and life got started," said Joseph Nuth of NASA's Goddard Space Flight Center, Greenbelt, Md. Second, it regularly crosses Earth's orbit, so it might impact us someday.

Nuth is Project Scientist for the proposed OSIRIS mission, which will "return a pristine sample of the scientifically priceless asteroid RQ36 to Earth for in-depth study," said University of Arizona Lunar and Planetary Laboratory (LPL) Director Michael Drake, Principal Investigator for the proposed mission. The mission will be the first to return a sample of an asteroid to Earth. NASA Goddard is managing the project. Lockheed Martin is building the flight system, the sampling mechanism, and the sample return capsule. Lockheed Martin is also performing spacecraft operations.

The OSIRIS team recently won a $1.2 million award from NASA to develop a more detailed engineering study of how the mission will accomplish its scientific objectives. OSIRIS will launch in 2011, acquire a sample of RQ36 in 2013, and return it to Earth in 2017.

"Proposed Mission Will Return Sample from Near-Earth Object"
09 March 2007

Link: NASA Article

The Planetary Society NEO Observations Grants (and Executive Director Friedman Reviews the 2007 PD Conference)

These awards were announced at the same time as the 2007 Planetary Defense Conference was being held. Louis D. Friedman, executive director of The Planetary Society, was at the conference. He has his own review of the conference here.

"The Planetary Society again advanced the search for comets and asteroids that might someday strike our planet by awarding Gene Shoemaker Near Earth Object Grants (NEO) to seven researchers from five countries. Last night the winners were announced at the Planetary Defense Conference, a gathering of professional NEO researchers from around the world, being held in Washington, D.C. The 2007 recipients are Robert E. Holmes, Jr, Donald P. Pray, and Brian D. Warner of the USA; Jean-Claude Pelle of French Polynesia; Quanzhi Ye of China; Eric J. Allen of Canada; and Giovanni Sostero of Italy. The Society received 23 proposals from 11 countries."

Link: Planetary Society Press Release (07 March 2007)

Link: Review by Louis Friedman of the 2007 Planetary Defense Conference

Roundup of recent flurry of articles on Planetary Defense

Since the 2007 Planetary Defense Conference in early March 2007 there is a flurry of online media articles on this issue. Instead of separate posts for each article I have listed below many of them in this one post (with relevant passages from said sources). The article it seemed most often referenced in domestic U.S. newspaper websites was an early [right as the 2007 Planetary Defense Conference was starting] Associated Press article entitled: "NASA Can't Pay for Killer Asteroid Hunt".

"NASA Can't Pay for Killer Asteroid Hunt"
Seth Borenstein
Associated Press (AP)
05 March 2007

Selections from the article...

NASA officials say the space agency is capable of finding nearly all the asteroids that might pose a devastating hit to Earth, but there isn't enough money to pay for the task so it won't get done. The cost to find at least 90 percent of the 20,000 potentially hazardous asteroids and comets by 2020 would be about $1 billion, according to a report NASA will release later this week. The report was previewed Monday at a Planetary Defense Conference in Washington.

"We know what to do, we just don't have the money," said Simon "Pete" Worden, director of NASA's Ames Research Center.

Link: Article (, 05 March 2007)

Link: Posting of Article on Slashdot and Reactions of Their Readers


"When the Sky Falls, Where Will NASA Be?"
Scientific American (SCIAM) Blog, Editors of Scientific American
13 March 2007

Selections from the article...

Everybody duck and cover. Last week NASA shrugged and told Congress that it neither has the funding nor the resources to meet its goal of identifying 90 percent of near-Earth asteroids (NEAs) 150 yards or more in diameter by 2020.

It seems that NASA has passed the buck it claims it doesn't have to other space agencies, institutions and facilities, saying NEA tracking is not a question of feasibility but funding. This includes not having available dedicated telescopes, including the Arecibo telescope in Puerto Rico, which will probably close or have its operations severely downgraded by 2011. (See this and this.) It is bad enough that we may lose Arecibo, which is one of the best-suited for the job of planetary watchdog, but NASA says it will have to rely on the kindness of others to do even the preliminary work to meet the goals called for by Congress in NASA's 2005 authorization bill.

And, though a killer-asteroid is not currently on track to vaporize Pretoria or Peoria or anywhere, at least as far as we know, it did not say who exactly would be funding research on NEA diversion and destruction technology should this situation ever visit itself upon the only planet we have. NASA's balk, according to a March 9 story in the Washington Post did not sit too well with Rep. Bart Gordon (D-Tenn.), the chairman of the House Committee on Science and Technology, who said: "We are still reviewing the report, but it's clear that NASA's recommended approach isn't a credible plan to achieve the goal specified in the NASA Authorization Act." The Committee will continue to pursue this issue in the coming year with the goal of obtaining a more responsive approach," he declared.

It is a sad day when our premier agency of exploration shows less imagination and foresight than an elected government official.

Link: Scientific American (SCIAM) Blog

Leonard David States Longer Version of NASA 2007 NEO Report Out There

Leonard David [] has more on the full release of the NASA Analysis of Alternatives Report, from his blog on

A months-in-the-making NASA report to Congress on asteroids has reached the desks of lawmakers. The congressionally-mandated appraisal — Near-Earth Object Survey and Deflection Analysis of Alternatives — is a 27-page chunk from a longer, over 270-page “limited edition” report...One early responder to the report is not too pleased. “We are still reviewing the report, but it’s clear that NASA’s recommended approach isn’t a credible plan to achieve the goal specified in the NASA Authorization Act. The Committee will continue to pursue this issue in the coming year with the goal of obtaining a more responsive approach,” said House Committee on Science and Technology Chairman Bart Gordon (D-TN)...I’ve been told than an electronic version of the larger report is being held up as it’s not yet suitable for the visually impaired.

Link: LiveScience Blog [10 March 2007]

Rusty has an Op-Ed in the New York Times

Selections from the op-ed follow:

Last week two events in Washington — a conference on “planetary defense” held by the American Institute of Aeronautics and Astronautics, and the release by NASA of a report titled “Near-Earth Object Survey and Deflection Analysis of Alternatives” — gave us good news and bad on this front. On the promising side, scientists have a good grasp of the risks of a cosmic fender-bender, and have several ideas that could potentially stave off disaster. Unfortunately, the government doesn’t seem to have any clear plan to put this expertise into action.

But instead of coming up with a plan and budget to get the job done, the report bluntly stated that “due to current budget constraints, NASA cannot initiate a new program at this time.” Representative Bart Gordon, Democrat of Tennessee, was right to say that “NASA’s recommended approach isn’t a credible plan” and that Congress expected “a more responsive approach” within the year.

Why did the space agency drop the ball? Like all government departments, it fears the dreaded “unfunded mandate”; Congress has the habit of directing agencies to do something and then declining to give them the money to do so. This is understandable. But in this case, Congress not only directed NASA to provide it with a recommended program but also asked for the estimated budget to support it. It was a left-handed way for the Congress to say to NASA that this is our priority ... like it or not. But for some reason NASA seems to have opted for a federal form of civil disobedience.

In the end, of course, this is not just America’s problem, as an asteroid strike would be felt around the globe. The best course is international coordination on deflection technology, along with global agreements on what should be done if a collision looks likely. Along these lines, the Association of Space Explorers, a group of more than 300 people from 30 nations who have flown in space (of which I am a member), is beginning a series of meetings in cooperation with the United Nations to work out the outlines of such an agreement.

Still, as with many global issues, little will be accomplished unless the United States takes the lead. With the entire planet in the cross hairs, NASA can’t be allowed to dither. If Congress’s mandates and budget requests aren’t energizing the agency, perhaps public hearings would shame it into action.

New York Times
Op-Ed Contributor
"The Sky Is Falling. Really"
16 March 2007

Link: Article

15 March 2007

Day 1: 2007 Plantetary Defense Conference - UPDATED

Introduction and Welcome
Dr. Bill Ailor
The Aerospace Coporation

Conference chairman Dr. Bill Ailor, from The Aerospace Corporation, provided introductory remarks. He stated that there were more sponsors this year than in previous years. The objectives for this conference were stated as follows:

Objectives of conference:
1. Threat posed by asteroid and comets
2. Mitigation approaches
3. Consequences of impacts
4. Human and disaster response dimensions
5. Political, policy, and legal issues
6. Develop a white paper with findings and recommendations

There will be various sessions including: Discovery and Characterization, Deflection Techniques, Deflection Missions and Technology, Impacts and Effects, Preparing the Public, Political and Policy issues, and finally a Panel Discussion. One of the outcomes of this conference is supposed is the creation of a white paper. This white paper will be discussed at the conference and most likely worked on for several months afterwards. There will be a reception at 5pm on 05 March 2007. In addition, there will be a Planetary Society special event at 7pm on 06 March 2007 (also at the Marvin Center).

Dr. Simon P. “Pete” Worden
Director, NASA Ames Research Center

Dr. Worden used to work with United States Senator Brownback (R-Kansas) on space issues. Apparently, the talk he gave at the last planetary defense conference in 2004 was one of his last within the military. There was an issue with his PowerPoint charts (as there seemed to be with many of the presentations, issues with the A/V setup). Worden said that he being “29 years in the Air Force [he] cannot talk without these charts.” Worden talked about the progress since 2004 in terms of the both space exploration and the NEOs. He placed emphasis on the Vision for Space Exploration (VSE), the major event since the last conference. He stated that we are well along on detecting large NEOs. He particularly mentioned Rusty Schweiert and other people’s work in getting public interested in Apophis,. He credited his colleagues with naming Apophis,, apparently his wife watches the television show Stargate in which there is a character with the same name. A big issue to him was where are we [they] are going to find money to do these things,. He stated that they do not yet have money to do much in this area and stated that everything we [they] do in this area needs to be colored [I assume by the implications of the VSE].

In terms of his point of the Vision for Space Exploration (VSE), he stated that the VSE involved a bipartisan support (see NASA Authorization Bill of 2005) that includes all the right words but does not make explicit statements on programs. The VSE includes statements that one of the key roles is to extend human presence through robotic exploration and international and commercial participation. He stated that the community needs to have the ability to take hardware for exploration and format some NEO studies from them.

Worden stated that in Congressional legislation for VSE, there are explicit instructions for NASA to conduct a survey program, with the appropriations bill specifically directing NASA to look at how to survey hazardous objects (I believe these were the 140m to 1km sized objects). Congress has asked NASA for a study to be delivered (the Analysis of Alternatives study, which was close to being delivered to Congress this week and mentioned repeatedly at the conference).

Warden said another major accomplishment since the last conference was that in 2004 Sen. Brownback had a hearing on NEOs. However, when Brownback went to his home district in Kansas and told the folks at the local barbershop about NEOs (and the Tunguska event), they laughed. This story was referred to several times during the conference as evidence of the “giggle” factor when it concerns NEOs. After this experience, Brownback stated that he was not going to talk about NEOs anymore.

Worden said that NASA 2006 Analysis of Alternatives (AoA) study was good and actually showed some charts from the study. Worden stated that if space-based NEO observation is pursued then his center will put forward proposals for such space-based assets. Worden stated that the NASA Administrator has told Congress recently that NASA will not reprogram any money into this area unless given explicit instructions and that this area [NEOs] “does not represent a new funding request or a commitment on the part of NASA.”

Recently, there have press articles about a NASA study that has looked at how to use exploration architecture elements such as the Crew Launch Vehicle (CLV) and Cargo Launch Vehicle (CaLV) for human missions to asteroid. Worden shed more light on this study by saying that many folks within NASA “conspired” to create and execute this study. Thus my interpretation is that this is a side study (one of many NASA normally does) by a small group with NASA and does not represent any mainline NASA Constellation Program office decision.

In regards to this idea of human asteroid missions, Worden stated that vision of the Orion Crew Exploration vehicle (CEV) hanging off asteroid like Itokawa (target of the Japanese Hayabusa mission) is an exciting one. Worden showed charts from this human asteroid mission study (apparently being worked upon by Ed Lu and others, the idea was initially brought to Worden by Lu). Particular charts Worden showed included various Earth-to-orbit (ETO) launch manifests for NEO mission launch concepts (including Ares I, IV, and V). Worden talked about charts that indicated that it would be quite feasible to send a human mission to an asteroid. He stated simple modifications would be needed for the CEV. This would result in minimal weight increases, potentially adding 587 lbs. From quickly scanning the charts it appeared that the mission would include a human crew of two for a 60-90 day mission. They have apparently examined several varieties of potential targets, but still do not today have a good set of targets using the Ares IV and Ares V launch vehicles. One body of interest discussed in the study was 2000 SG344. However, this object will not be available until 2069 for such a human asteroid mission. Thus there appears to be a need to find potential targets. Overall, Worden stated that human missions to asteroid are feasible and will raise general public/international interest, adding impetus to find the objects themselves.

Another piece of the NEO issue addressed by Worden was characterization. However, he addressed it in an unexpected manner (slightly unexpected by me and some in the audience). He stated that NASA Ames is trying to build nano-satellites Earth-to-Orbit (ETO) launch vehicles. Worden stated that satellites weighing 5-10 kg can be built that provide useful capabilities. He stated that such spacecraft could potentially have 1 kg of payload. They could be useful for a wide variety of NEO applications including a variety of in-situ studies for a few millions of dollars. This seemed to be a non-subtle advertisement for NASA Ames and its capabilities.

Worden also stated the obvious about this field, that the key limitation is money. He stated that NEOs are a key potential direction for the VSE. He stated that they are implicit in everything NASA is doing, could be more explicit as time goes on. He stated that the possibilities of affordable nano-satellites are very interesting. Worden concluded his main remarks by stating that there is still some “giggle factor” on this issue but the large number of sponsors of the 2007 conference (as compared to the 2004 conference) shows that this problem is lessening, though it is still somewhat of an issue. Worden stated that people should “hit other NASA people for money, not me.”

In the question and answer (Q&A) session there was discussion of using nano-satellites for Low Earth Orbit (LEO) access. There may be more done with secondary payloads (see the ESPA secondary payload adapter recently launched on the Atlas V orbital express mission). Worden stated that interesting things can be done with smallsats. As an example, he has asked people if they could figure out what they can do for 1 kg of payload in different locations in the solar system (paraphrase: “If I gave you a kilogram in the right location, what can you do?”). There was talk that nanotechnology could also be an enabler.

Worden stated that on that particular day he was going to talk out the Department of Defense. He stated that he loves to spend their money. He told the audience about talking to a colonel about this issue, specifically talking about the K-T impactor 6 5million years ago. The response was that if there was not going to a large probability of an event this year, and that it could be a few million years, they the DoD thinks they can defer this issue until next year. The moral of this story is that the budget horizons of these agencies is very short and that the most likely funding will not be for missions but technology development. He stated the obtaining DoD funding [edited from original post] of the Clementine mission to the moon was an “artful conspiracy.”

Session 1A: Discovery & Characterization
Chair: David Morrison, NASA Ames Research Center

Note: David Morrison currently describes himself as an astrobiologist.

Poster Papers: Several of the poster paper presenters did not show up. Presenters for the Gritsevich, Ivashkin, and Bagrov poster papers did not show up. A paper from Messrs. Cleve and Arentz from Ball Aerospace was the only paper presented during the interactive poster session at the beginning of this session. Like other conferences, this conference has been experimenting with giving traditional poster papers (papers normally not given a speaking slot) 2-3 minutes to present an overview of their work. The upcoming International Astronautical Conference (IAC) will also be having these “interactive” poster sessions. Cleve presented in place of Bob Arentz on “The Impact of Deep Impact.” The short presentation went over the Deep Impact mission (an approximately 400 kg impactor spacecraft). Cleve suggested that kinetic energy deflection is attractive if warning times are less than 30 years.

Current NASA Discovery/Characterization Efforts: The Recommendations of the 2003 SDT report and the Dec. 2005 Congressional request
Donald Yeomans
NASA Jet Propulsion Laboratory

There are 350,000 minor planets. Yeomans went through a history of recent NEO workshops and government reports. This included the 1992 Near-Earth Object Interception Workshop that took place in Washington, D.C. that favored nuclear intercept and recommended a 2.5 m optical telescope for NEOs. In 1995 the “Eugene Shoemaker report” (the 1995 Near Earth Objects Survey Workgroup Report) related that 90% of objects over 1km in diameter should be found, which became the NASA headquarters goal to the House Science Committee. He then related the goals of the current Spacegaurd survey (find 90% of all NEAs larger than 1 km in diameter by the end of 2008). Yeomans said the new NASA report, the Analysis of Alternatives report to Congress, will get a limited release (later on in the conference, he stated that only about 100 copies has been printed for distribution and though that only a summary version of the report would be presented). At this point in the conference, he was not sure if the report was delivered to Congress.

Yeomans stated that Apophis is the poster child for near earth objects. Every 600 years it passes close to the Earth and is expected to hit the Earth every 23,000 years. He stated that Apophis is a 270 m sized [diameter] object discovered in June 2004 and that on April 13, 2029 it will pass 5.06 radaii above Earth’s surface, having a 1/45,000 chance of Earth impact in 2036. He stated Apophis will be a “naked eye” object for people living in western Europe/northern Africa (Apophis will have a magnitude of 3.5, note: the star Sirius shines at magnitude –1.5, Venus is as –4.4, and the full Moon is about –12.5). Apophis will be traveling through the constellation Cancer at 42 degrees per hour.

Questions on Recent NASA NEO AoA Study (Is there more to the report?)

Here are some questions I have sent to Lindley Johnson, head of the NASA NEO office, in regards information in the recent NASA Near Earth Object (NEO) Analysis of Alternatives (AoA) report that was delivered to Congress last week. I am waiting for a response.

1. The public report that was released seemed like an executive summary. At the 2007 PD conference last week, Don [Yeomans] has foretold that the publicly released study would be an executive summary. Last week's presentations revealed data/charts that were not in the publicly released report. Is this the complete report? If not, when will the information shown last week and potentially done for the study be released. I believe in the spirit of openness within this community it would helpful to have as a complete a picture of this study as possible. Also it would be helpful if along with the study any briefing charts could also be publicly released.

2. Does the reference (Shared PS4 and LSST) case cost (p. 19 of the study) of $469M to 2026 include the current $4.1M NEO program cost? Did the study assume that this money would not be reprogrammed to the PS4/LSST reference capability but continue (thus current "NEO" optical observatories would continue)?

3. Do the costs given for these options include the data management cost? How much of the $469M is data management and which option was chosen for the reference (Shared PS4 and LSST) case? What are the costs for the different data management options?

4. Is it possible to get a year by year breakout of the costs, specifically the $469M? It would be helpful in planning for the white paper if one could see what funding would be needed in the immediate 2-5 years if the reference case were to be implemented.

5. The performance of the different mitigation options was shown, but not the costs. Is it possible to provide this information?

6. Was there any more thought as to radar? Were there any costs assumed for keeping current radar capabilities going or for the new bistatic 100m radar shown in table 5 of the report?

Audio Story on 2007 Planetary Defense Conference

"The U.S. space agency, NASA, says it doesn't have the money to track the asteroids and comets that could potentially hit the Earth, even though it has the technical ability to do it. The announcement followed a recent symposium at the annual meeting of the American Association for the Advancement of Science where experts described how a killer asteroid could be deflected … if it's found in time."

"Astronomers Seek Ways to Divert 'Killer Asteroids' that Could Threaten Earth"
Art Chimes
San Francisco
Voice of America
14 March 2007

Link: Article

Link: Chimes report (MP3) - Download 1.37 MB audio clip
Link: Listen to Chimes report (MP3) audio clip
Link: Chimes report (Real) - Download 907 k audio clip
Link: Listen to Chimes report (Real) audio clip

13 March 2007

National Public Radio (NPR) Stories on 2007 Conference and NASA AoA Report

There are several National Public Radio (NPR) reports on the recently concluded 2007 Planetary Defense Conference and the release of the NASA NEO Analysis of Alternatives (AoA) report.

"NASA Report on Asteroids Suggests Nuclear Option"
Nell Boyce
National Public Radio (NPR) Morning Edition

Morning Edition, March 13, 2007. Scientists have sent Congress a report on ways to prevent an asteroid from hitting Earth. Among the proposals: use nuclear weapons to nudge a big space rock off a collision course. Some scientists don't think much of that idea.

Link: Story

"Scientists Gather at Conference to Stop Asteroids"
Alex Chadwick
National Public Radio (NPR) Day to Day

Day to Day, March 5, 2007. A Planetary Defense Conference that starts Monday will look into possible methods of preventing asteroids from hitting Earth. William Ailor, a director with The Aerospace Corporation, talks about the threat of a direct hit.

Link: Story

"A Call for an Asteroid Response Team"
National Public Radio (NPR) Talk of the Nation

Talk of the Nation, February 23, 2007. Researchers call for an international effort, potentially coordinated by the United Nations, to act as a planetary response team for potential space threats. Though sky watchers have not located any definite threats so far, one worry is that by the time a threat is spotted, it will be too late for any one country to be able to take useful action on its own. Guest: David Morrison, senior scientist, NASA Astrobiology Institute, NASA Ames Research Center

Link: Story

NASA Report on NEOs Finally Available to the Public

The Near-Earth Object Survey and Definition Analysis of Alternatives report is finally available. This was a Report to Congress delivered in March 2007 and discussed all last week at the 2007 Planetary Defense Conference

Link: Report Site
Link: Report (.PDF)

From the Report Site...

Section 321 of the NASA Authorization Act of 2005 (Public Law No. 109-155), also known as the George E. Brown, Jr. Near-Earth Object Survey Act, directs the NASA Administrator to transmit an initial report to Congress not later than one year after the date of enactment that provides: (1) an analysis of possible alternatives that NASA may employ to carry out the survey program of near-Earth Objects (NEO), including ground- based and space-based alternatives with technical descriptions; (2) a recommended option and proposed budget to carry out the survey program pursuant to the recommended option; and (3) an analysis of possible alternatives that NASA could employ to divert an object on a likely collision course with Earth.

The objectives of the George E. Brown, Jr. NEO Survey Program are to detect, track, catalogue, and characterize the physical characteristics of NEOs equal to or larger than 140 meters in diameter with a perihelion distance of less than 1.3 AU (Astronomical Units) from the Sun, achieving 90 percent completion of the survey within 15 years after enactment of the NASA Authorization Act of 2005. The Act was signed into law by President Bush on December 30, 2005.

A study team, led by NASA's Office of Program Analysis and Evaluation (PA&E), conducted the analysis of alternatives with inputs from several other U.S. government agencies, international organizations, and representatives of private organizations. The team developed a range of possible options from public and private sources and then analyzed their capabilities and levels of performance including development schedules and technical risks.

Key Findings for Diverting a Potentially Hazardous Object (PHO):
The study team assessed a series of approaches that could be used to divert a NEO potentially on a collision course with Earth. Nuclear explosives, as well as non-nuclear options, were assessed.

  • Nuclear standoff explosions are assessed to be 10-100 times more effective than the non-nuclear alternatives analyzed in this study. Other techniques involving the surface or subsurface use of nuclear explosives may be more efficient, but they run an increased risk of fracturing the target NEO. They also carry higher development and operations risks.

  • Non-nuclear kinetic impactors are the most mature approach and could be used in some deflection/mitigation scenarios, especially for NEOs that consist of a single small, solid body.

  • "Slow push" mitigation techniques are the most expensive, have the lowest level of technical readiness, and their ability to both travel to and divert a threatening NEO would be limited unless mission durations of many years to decades are possible.

  • 30-80 percent of potentially hazardous NEOs are in orbits that are beyond the capability of current or planned launch systems. Therefore, planetary gravity assist swingby trajectories or on-orbit assembly of modular propulsion systems may be needed to augment launch vehicle performance, if these objects need to be deflected.
Recommended Survey Program
Currently, NASA carries out the "Spaceguard Survey" to find NEOs greater than 1 kilometer in diameter, and this program is currently budgeted at $4.1 million per year for FY 2006 through FY 2012. We also have benefited from knowledge gained in our Discovery space mission series, such as the Near Earth Asteroid Rendezvous (NEAR), Deep Impact, and Stardust missions that have expanded our knowledge of near-Earth asteroids and comets. Participation by NASA in international collaborations such as Japan's Hayabusa mission to the NEO "Itokawa" also greatly benefited our understanding of these objects. NASA's Dawn mission, expected to launch in June 2007, will increase our understanding of the two largest known main belt asteroids, Ceres and Vesta, between the planets Mars and Jupiter. NASA conducts survey programs on many celestial objects - the existing Spaceguard program for NEOs, surveys for Kuiper Belt Objects, the search for extra-solar planets, and other objects of interest such as black holes to understand the origins of our universe. Our Discovery mission series in planetary science may offer additional opportunities in the future beyond our current survey efforts.

NASA recommends that the program continue as currently planned, and we will also take advantage of opportunities using potential dual-use telescopes and spacecraft - and partner with other agencies as feasible - to attempt to achieve the legislated goal within 15 years. However, due to current budget constraints, NASA cannot initiate a new program at this time.

12 March 2007

Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is causing the spin of asteroid 2000 PH5 to speed up at the rate of about one millisecond per year

"Astronomers have found that the weak but constant force of sunlight is causing the spin of a small asteroid to accelerate. In a paper published online by Science last week, a group of astronomers said than the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is causing the spin of asteroid 2000 PH5 to speed up at the rate of about one millisecond per year. The YORP effect is created when an asteroid or other body absorbs sunlight and reradiates it as heat. While normally a feeble force, the YORP effect can cause measurable changes in small, irregularly-shaped bodies like this asteroid. Researchers ruled out all other known potential causes for the change in the asteroid's spin, including tidal forces created when the asteroid passes the vicinity of the Earth. The YORP effect may explain why very small asteroids spin either very quickly or very slowly."

From Science Express (08 March 2007):

Published Online March 8, 2007
Science DOI: 10.1126/science.1139040
Science Express Index
Submitted on December 19, 2006
Accepted on February 23, 2007

Direct Detection of the Asteroidal YORP Effect
Stephen C. Lowry 1*, Alan Fitzsimmons 1, Petr Pravec 2, David Vokrouhlicky 3, Hermann Boehnhardt 4, Patrick A. Taylor 5, Adrian Galád 6, Mike Irwin 7, Jonathan Irwin 7, Peter Kusnirák 2
1 School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK.
2 Astronomical Institute, Academy of Sciences of the Czech Republic, Fricova 1, CZ-25165 Ondrejov, Czech Republic.
3 nstitute of Astronomy, Charles University, V Holesovickách 2, 18000 Prague 8, Czech Republic.
4 Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau, Germany.
5 Department of Astronomy, Cornell University, Ithaca, NY 14853, USA.
6 Department of Astronomy, Physics of the Earth, and Meteorology, Faculty of Mathematics, Physics and Informatics, Comenius University, 842 48 Bratislava, Slovakia.
7 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK.
* To whom correspondence should be addressed. Stephen C. Lowry , E-mail:

The Yarkovsky-O'Keefe-Radzievskii-Paddack effect is believed to alter the spin states of small bodies in the solar system. However, evidence for the effect has so far been indirect. Here we report precise optical photometric observations acquired over four years of a small near-Earth asteroid (54509) 2000 PH5. We find the asteroid has been continuously increasing its rotation rate {omega} over this period by d{omega}/dt = 2.0 (±0.2) x 10-4 degrees/day2. We simulated the close Earth approaches from 2001-2005, showing that gravitational torques cannot explain the observed spin-rate increase. Dynamical simulations also suggest that 2000 PH5 may reach a rotation period of ~20 seconds towards the end of its expected lifetime.

Link: Science Express Abstract (08 March 2007)
Link: PDF of Supporting Material for Paper

Link: New York Times article
Link: article
Link: Reuters article
Link: New Scientist article
Link: ESO press release
Link: Cornell Univ. press release

10 March 2007

Finally, my notes from the 2007 Planetary Defense Conference

Since there was no wifi access for guests at the Marvin Center (where the 2007 Planetary Defense Conference was being held), I was not able to blog live. However, I took extensive notes and am currently cleaning them up for eventual posting. Thus over the next one to two days please anticipate seeing notes from each day. After I am done posting my daily notes, I shall endeavor to post my overall perspective on the conference.

02 March 2007

Live/Near-Live Blogging from the 2007 Planetary Defense Conference

I am off for the 2007 Planetary Defense Conference in Washington, D.C. It takes places next week from March 5-8, 2007. Hopefully I will be able to blog live there, if not I will upload notes from each day.

Link: 2007 Planetary Defense Conference

01 March 2007

Podcaset from Radio New Zealand (Morning Report show) on Asteroid Threat

Dr. John Olds, CEO of SpaceWorks Engineering, Inc. (SEI), was on the Radio New Zealand show Morning Report talking about the asteroid threat and the SEI MADMEN (Modular Asteroid Deflection Mission Ejector Node) multiple mass driver concept.

Radio New Zealand - Morning Report
Asteroid Threat
Scientists are warning an asteroid could come 'uncomfortably' close to Earth in 2036.
File Size:1.9MB
Date: (Fri, 02 Mar 2007 08:54:00 +1300)

Link: Radio New Zealand Morning Report podcast page

Link: Direct link to .mp3 of interview

The Current Interesting Case of Object 2004 BX159

From Asteroid/Comet connection (

2004 BX159 was posted as an impact risk by JPL on 14 Feb. 2007, which presented a bit of a mystery since apparently no astrometry has been made public for this kilometer-size object. The Minor Planet Ephemeris Service (MPES) shows that 2004 BX159 was discovered by unidentified astronomers at the European Southern Observatory on Cerro Paranal in Chile on 20 Jan. 2004, with two positions taken each night from the 20th to 23rd. An orbit was published in the DOU MPEC of 20 Aug. 2004, but, as far as A/CC can find, the observational data isn't available to the public, not via MPEC nor via NEODyS or AstDyS.

This may be embargoed data, which the Minor Planet Center (MPC) accepts from professional astronomers who use large telescopes to observe distant minor objects and who operate differently from those engaged in the discovery and tracking of potentially hazardous objects where openness and quick response are paramount. Or it may just be the kind of astrometric data that doesn't get published in MPECs, such as observations of Main Belt asteroids, and which may take awhile to appear in the AstDyS database.

The MPC's own risk analysis has an orbit calculation for 2004 BX159 that is far from hazardous, but JPL since Feb. 14th has been showing that it cannot rule out orbit solutions that intersect with Earth in August 2009 and in later years. This risk assessment is based on very little data and will, of course, change with more observations, when more observations can be made. Based on the MPC's nominal, non-hazardous orbit calculation, MPES indicates that this object had a slim recovery opportunity in mid-January, a month before it came to the attention of NEO observers, and that there is some possibility it can still be caught if a concerted effort is made now using larger telescopes through maybe June and then returning in November. The next best opportunity is indicated beginning next January and continuing through early December, brightening to perhaps magnitude V=19.4 in mid-April, which may be good enough for accidental, if not planned, recovery. Otherwise, MPES indicates that 2004 BX159 won't be next visible even for larger telescopes until around the time of JPL's first impact solution in 2009. Again, this viewability prediction comes from the MPC's nominal orbit calculation, which has 2004 BX159's Earth MOID (minimum orbit intersection distance) at 0.49034 AU, or more than 190 lunar distances (LD). JPL's own nominal orbit calculation classifies this object as not being a near-Earth object. Ephemerides for 2004 BX159 based on JPL's Earth-intersecting orbit calculations do not appear to be readily available.

Link: Consolidated Risk Tables: Asteroid/Comet Connection

Late Late Show with Craig Ferguson Talks About Apophis

From the Late Late Show with Craig Ferguson..."A giant asteroid is on it's way and we're all going to die."

Link: YouTube Video
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