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.

30 January 2008

Hubble will attempt to capture 2007 WD5 as it nears Mars

From the Planetary Society Blog:

...They're going to try to catch [2007] WD5 with the Hubble Space Telescope. An alert reader pointed me to various resources on the Space Telescope Science Institute website where you can read about plans for upcoming observations to be performed by Hubble. On this page, Keith Noll proposes in Hubble proposal 11407 "to observe 2007 WD5 prior to its possible impact with Mars. In the event that an impact does occur, we will also observe the asteroid as it approaches Mars, the impact itself, and the aftermath of the impact. HST has unique capabilities to observe this potentially very unusual event." Note that once any observations are performed, the same page will allow you to query the Hubble data banks for information the actual data. And on this other page, you can learn that of the five observations that Noll originally requested, the first four have been withdrawn; presumably these were the ones that would have been taken to observe the approach and impact. Only one set of observations is now planned, using the Wide Field and Planetary Camera 2 (WFPC2), running from January 30 at 10:45:28 to 11:05:00. Those observations are about an hour before the latest close approach time reported by JPL's Near Earth Object program.

Link: Planetary Society Blog Post

29 January 2008

Update from United Nations Office of Outer Space Affairs (UNOOSA): Draft Agenda Items on NEOs

From the agenda where the UN body will discuss various topics including NEOs...

[Agenda Item] 12. Near-Earth objects

In paragraph 10 (b) of its resolution 62/217, the General Assembly endorsed the recommendation of the Committee that the Subcommittee, at its forty-fifth session, should consider this item in accordance with the new multi-year workplan for the period 2008-2010, adopted by the Subcommittee at its forty-fourth session (A/AC.105/890, annex III, para. 7).

In accordance with the workplan, the Subcommittee, at its forty-fifth session, will take the following actions:

(a) Continue intersessional work;
(b) Consider the reports submitted in response to the annual request for information on near-Earth object activities;
(c) Update the interim report of the Action Team on Near-Earth Objects.

The reports mentioned in subparagraph (b) above are contained in document A/AC.105/896. The interim report of the Action Team on Near-Earth Objects for the period 2007-2008, mentioned in subparagraph (c) above, is contained in document A/AC.105/C.1/L.295.

In paragraph 15 of its resolution 62/217, the General Assembly agreed that the Subcommittee, at its forty-fifth session, should reconvene its Working Group on Near-Earth Objects, in accordance with the workplan under this item.

Link: Provisional Agenda for the United Nations Office of Outer Space Affairs (UNOOSA) Scientific and Technical Subcommittee: 2008

Don Yeomans Video Roundup on Asteroid 2007 TU24

Link: YouTube Video: "Asteroid 2007 TU24 Close Approach"

Link: NASA Downloadable Video of Don Yeomans

28 January 2008

Analysis of Stardust materials reveals similarity to asteroids

Getting into the details: Stardust impact tracks and light gas gun impacts of sulfide in aerogel both display metal beads with sulfide rims indicating that GEMS-like objects in Stardust are generated by impact mixing of comet dust with silica aerogel. (left) Stardust GEMS-like material and (right) light gas gun shot GEM-like material. GEMS in cometary IDPs do not contain sulfide-rimmed metal inclusions. [Image credit: Hope Ishii, LLNL]

Stardust impact tracks created by comet dust entering silica aerogel at 6 km/s. [Image credit: NASA/JPL]

From the article...

Contrary to expectations for a small icy body, much of the comet dust returned by the Stardust mission formed very close to the young sun and was altered from the solar system’s early materials.

When the Stardust mission returned to Earth with samples from the comet Wild 2 in 2006, scientists knew the material would provide new clues about the formation of our solar system, but they didn’t know exactly how.

New research by scientists at Lawrence Livermore National Laboratory and collaborators reveals that, in addition to containing material that formed very close to the young sun, the dust from Wild 2 also is missing ingredients that would be expected in comet dust. Surprisingly, the Wild 2 comet sample better resembles a meteorite from the asteroid belt rather than an ancient, unaltered comet.

Comets are expected to contain large amounts of the most primitive material in the solar system, a treasure trove of stardust from other stars and other ancient materials. But in the case of Wild 2, that simply is not the case.

By comparing the Stardust samples to cometary interplanetary dust particles (CP IDPs), the team found that two silicate materials normally found in cometary IDPs, together with other primitive materials including presolar stardust grains from other stars, have not been found in the abundances that might be expected in a Kuiper Belt comet like Wild 2. The high-speed capture of the Stardust particles may be partly responsible; but extra refractory components that formed in the inner solar nebula within a few astronomical units of the sun, indicate that the Stardust material resembles chondritic meteorites from the asteroid belt.

Link: LLNL Press Release

Link: New Scientist Article

Roundup of Articles on 2007 TU24

These low-resolution radar images of asteroid 2007 TU24 were taken over a few hours by the Goldstone Solar System Radar Telescope in California's Mojave Desert. Image resolution is approximately 20-meters per pixel. Next week, the plan is to have a combination of several telescopes provide higher resolution images. Image credit: NASA/JPL-Caltech

From the article...

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800 feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000 kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time).

Link: NASA Article on Goldstone observations

Link: Washington Post Article

Link: NASA JPL Information

First Image of Approaching Asteroid"
Jeanna Bryner
28 January 2008

Link: article

23 January 2008

New modeling of Chicxulub asteroid impact reveals larger environmental impact than previously thought

Selections from the article...

The most detailed three-dimensional seismic images yet of the Chicxulub crater, a mostly submerged and buried impact crater on the Mexico coast, may modify a theory explaining the extinction of 70 percent of life on Earth 65 million years ago.

The Chicxulub crater was formed when an asteroid struck on the coast of the Yucatan Peninsula. Most scientists agree the impact played a major role in the "KT Extinction Event" that caused the extinction of most life on Earth, including the dinosaurs.

According to Sean Gulick, a research scientist at the Institute for Geophysics at The University of Texas at Austin's Jackson School of Geosciences and principal investigator for the project, the new images reveal the asteroid landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere.

The impact site also contained sulfur-rich sediments called evaporites, which would have reacted with water vapor to produce sulfate aerosols. According to Gulick, an increase in the atmospheric concentration of the compounds could have made the impact deadlier in two ways: by altering climate (sulfate aerosols in the upper atmosphere can have a cooling effect) and by generating acid rain (water vapor can help to flush the lower atmosphere of sulfate aerosols, causing acid rain). Earlier studies had suggested both effects might result from the impact, but to a lesser degree.

"The greater amount of water vapor and consequent potential increase in sulfate aerosols needs to be taken into account for models of extinction mechanisms," says Gulick.

"Seismic Images Show Dinosaur-Killing Meteor Made Bigger Splash"
January 23, 2008
Press Release
University of Texas at Austin

Link: Press Release


"Importance of pre-impact crustal structure for the asymmetry of the Chicxulub impact crater"
Nature Geoscience
Published online: 13 January 2008
Sean P. S. Gulick, el al.

Impact craters are observed on the surfaces of all rocky planets and satellites in our Solar System1; some impacts on Earth, such as the Cretaceous/Tertiary one that formed the Chicxulub impact crater have been implicated in mass extinctions. The direction and angle of the impact—or its trajectory—is an important determinant of the severity of the consequent environmental damage, both in the downrange direction (direction bolide travels) and in the amount of material that enters the plume of material vaporized on impact. The trajectory of the Chicxulub impact has previously been inferred largely from asymmetries in the gravity anomalies over the crater. Here, we use seismic data to image the Chicxulub crater in three dimensions and demonstrate that the strong asymmetry of its subsurface correlates with significant pre-existing undulations on the end-Cretaceous continental shelf that was the site of this impact. These results suggest that for rocky planets, geological and geomorphological heterogeneities at the target site may play an important role in determining impact crater structure, in addition to impact trajectories. In those cases where heterogeneous targets are inferred, deciphering impact trajectories from final crater geometries alone may be difficult and require further data such as the distribution of ejecta.

Link: Abstract from Nature Geoscience

Link: Full PDF of Paper

22 January 2008

Asteroid 2007 TU24 Potentially Visible from Earth on 28 Jan 2008

The illustration below is courtesy of amateur astronomer Dr. Dale Ireland from Silverdale, WA. The illustration shows the asteroid's [2007 TU24] track on the sky for 3 days near the time of the close Earth approach as seen from the city of Philadelphia.

From Don Yeomans at JPL NEO:

Asteroid 2007 TU24, discovered by the Catalina Sky Survey on October 11, 2007 will closely approach the Earth to within 1.4 lunar distances (334,000 miles) on 2008 Jan. 29 08:33 UT. This object, between 150 and 600 meters in diameter, will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves further from Earth. For a brief time the asteroid will be observable in dark and clear skies with amateur telescopes of 3 inch apertures or larger.

Link: Article

19 January 2008

Scott Hubbard and Others to Discuss Alternative NASA Vision

This Aviation Week article discusses something I have thought about recently. As the next presidential election occurs, there will be opportunities for a revaluation of the Vision for Space Exploration (VSE), which is so closely tied to the current President Bush. It seems Scott Hubbard is bringing people together to discuss an alternative approach of using Orion and Ares I/V hardware for asteroid and observatory missions in preparation for future Mars missions. We will see where this goes. I have issues with the article since the recent NASA humans to NEO study was very poor in identifying near term opportunities for human missions (something the study seemed to gloss over in my opinion).

I also have some comments on the quotation given my Mike Griffin in the article on non-Moon human exploration destinations for the near term. Here is his quote and my quick comments:

"A large portion of the scientific community in the U.S. also prefers Mars over the Moon," he [NASA Administrator Mike Griffin] acknowledged. But "interest in the Moon is driven by goals in addition to and beyond the requirements of the science community. It is driven by the imperatives that ensue from a commitment to become a spacefaring society, not primarily by scientific objectives, though such objectives do indeed constitute a part of the overall rationale."

I would argue that the ultimate goals for a spacefaring civilization are colonization, resource extraction, and protection. In my opinion, asteroid missions and Mars missions meet our spacefaring objectives more comprehensively versus lunar missions. Update on 22 Jan 2008: I believe the previous statement because I fear a lunar outpost in the late 2020s will become like the ISS of today: a facility that once constructed will be abandoned. This is what the ISS will become once it is "relatively" complete by space shuttle retirement in 2010. By then it most likley will only have a few years of "operational" life left. I believe any lunar base attempt, given current mindsets, will be abandoned once we say that we have accomplished our decadal human exploration of the moon and are ready for Mars. What happens to any moonbase we have developed and the $100-$150B it took to make it? Should we not just go ahead to the ultimate destination. Previously, I was a "moon" person and thought we should go back to the moon before Mars. But as I see how NASA as a government entity is actually attempting to do it, I an becoming more skeptical that it will accomplished in the manner laid out in terms of capability, cost, or schedule.

Other selections from the article...

Top U.S. planetary scientists, several astronauts and former NASA division directors will meet privately at Stanford University on Feb. 12-13 to define these sweeping changes to the NASA/Bush administration Vision for Space Exploration (VSE).

Abandoning the Bush lunar base concept in favor of manned asteroid landings could also lead to much earlier manned flights to Mars orbit, where astronauts could land on the moons Phobos or Deimos.

Their goals for a new array of missions also include sending astronauts to Lagrangian points, 1 million mi. from Earth, where the Earth's and Sun's gravity cancel each other out and spacecraft such as replacements for the Hubble Space Telescope could be parked and serviced much like Hubble.

Numerous planetary managers told Aviation Week & Space Technology they now fear a manned Moon base and even shorter sorties to the Moon will bog down the space program for decades and inhibit, rather than facilitate, manned Mars operations--the ultimate goal of both the Bush and alternative visions. The first lunar sortie would be flown by about 2020 under the Bush plan.

If alternative-vision planners have their way, the mission could instead be flown to an asteroid in about 2025.

Some basic asteroid mission design work--part of it volunteer--using the CEV hardware is already underway at the Johnson Space Center (AW&ST Sept. 25, 2006, p. 21). Other, more in-depth and long-standing manned asteroid analysis is underway under International Astronautical Assn. and Smithsonian National Air and Space Museum sponsorship.

Scott Hubbard, consulting professor in the Stanford Aeronautics and Astronautics Dept., conceived the reassessment meeting. Hubbard was previously the director of NASA Ames Research Center and, before that, NASA Mars program director. "We have planned this invitation-only workshop to elicit frank and open discussion about the future of the 'vision' as the administration changes," he says.

"Space Leaders Work To Replace Lunar Base With Manned Asteroid Missions"
18 January 2008
Craig Covault

Link: Article

11 January 2008

NEO News (01/11/08) Mars safe & funds for LSST

From Dave Morrison:

NEO News (01/11/08) Mars safe & funds for LSST


PASADENA, Calif. (AP) - The possibility of a collision between Mars and an approaching asteroid has been effectively ruled out, according to scientists watching the space rock as it nears the Red Planet.

Tracking measurements of asteroid 2007 WD5 from four observatories have so greatly reduced uncertainties about its Jan. 30 close approach to Mars that the odds of an impact have dropped to 1 in 10,000, the Near-Earth Object Program at NASA's Jet Propulsion Laboratory said in a posting on its Web site Thursday. Scientists said the best estimate was for the asteroid to pass at a distance of more than 16,000 miles from the surface of Mars, or at worst, no closer than 2,480 miles.

The asteroid was discovered in November. Initial observations of its orbit raised the odds of an impact to as high as 1 in 25 before further refinements came in. The asteroid is big enough to have blasted a half-mile-wide crater in the cold and dusty Martian surface, an event that astronomers would have liked to observe.

The NEO program normally looks for asteroids and comets that could pose a hazard to Earth.


6 January 2008

Billionaire Bill Gates and former Microsoft colleague Charles Simonyi donate $30 million for telescope that can provide early warning of asteroid collision with Earth.

In the daytime the view from Cerro Pachon, a rocky, desolate peak high above Chile, offers a breathtaking vista of the Andes. Mountains of rock topped with snow and glaciers seem to touch the heavens. Come nightfall, the Andes disappear into gloom and then the real show begins. As if someone had flicked a switch, the gleam of millions of planets and stars studs the inky blackness overhead. The sky seems too immense to absorb, even for giant telescopes. They focus on one tiny portion at a time, pinpricks in the cosmos, because traditionally astronomers like to dwell on detail.

Not any more. Cerro Pachon is to host the Large Synoptic Survey Telescope (LSST), a near $400 million (£203 million) project that will survey the entire sky several times a week - something never done before. Every 15 seconds it will take an image seven times the diameter of the moon, adding up, every three days, to a full panorama of the heavens. Boasting 3,200 megapixels, it will be the world's biggest digital camera.

"Most telescopes look at a tiny part of the sky, to look deep and in detail. We want to look broadly, to cover everything," Victor Krabbendam, the deputy project manager, said Friday.

This week the telescope took a step closer to reality after donations from two geeky philanthropic billionaires who are entranced by the technology and its possibilities.

Bill Gates gave $10 million from his private fortune and a former Microsoft colleague, Charles Simonyi, gave $20 million through his Fund for Arts and Sciences. Gates, one of the world's richest men, said the telescope would turn astronomy into a software issue by writing code and database queries to mine the night sky and recover its secrets.

"LSST is truly an internet telescope which will put terabytes of data each night into the hands of anyone that wants to explore it. [It is] a shared resource for all humanity - the ultimate network peripheral device to explore the universe," he said.

The donations will keep on track the construction of three large mirrors and three refractive lenses which are the most important and expensive part of the machine.

The first stages of production for the two largest mirrors are under way at the Mirror Laboratory at the University of Arizona. Launched in 2000, the project is a partnership based in Tucson, Arizona, and split among 23 universities, laboratories and private entities. Once the mirrors are ready they will be hauled up the 2,690-meter peak and installed in a dome due for construction in 2011. "First light", as astronomers call their scoping, should begin four years later.

The camera is expected to take more than 200,000 pictures. Processing that information is expected to be the most technically difficult part of the project.

The camera's 15 second exposure should be long enough to record images of even very faint objects such as asteroids and so-called near-Earth objects. By monitoring them night after night, it should be possible to infer their orbit around the sun and hence how likely they are to slam into Earth.

That is how the project's director sold the LSST to congressmen in November. "The ability to detect virtually every potentially hazardous near-Earth object and determine its orbit with precision transforms that statistical threat into a deterministic prediction," said Anthony Tyson, at the University of California, Davis.

It will also be useful for basic science. Its time-lapse images can be used to create 3D maps of the mass distribution in the universe. That should not only help to trace billions of galaxies, but also tell cosmologists more about the mysterious and recently discovered "dark energy" that is driving the expansion of the universe.

Every night the telescope will pull in 30 terabytes of image data (about 190 times more than a top of the range iPod) which will be made available free on the internet. "People can find out what's going on everywhere in the sky, and no one has ever done that before - not even come close," said Donald Sweeney, the project manager. "There are lots of things that happen every night in the sky, and no one has been able to track them and detect them."

Cerro Pachon, located in northern Chile near the city of Vicuña, is a foothill of the Andes but high enough to escape haze and light pollution. It was chosen over a site in Mexico because it hosts two other large telescopes known as Gemini South and SOAR, delivering a ready-made astronomy infrastructure.

"It's very beautiful up there, very rocky and quiet. You can see glaciers in the distance," said Krabbendam.

This week's donations would keep the project on schedule by enabling the early fabrication of large optics and other long-lead components of the telescope system, said Sweeney.

When working together at Microsoft, Gates and Simonyi became fascinated with stretching software and the internet's possibilities. Simonyi, estimated to be worth $1 billion, is also obsessed by space. Last year be became the fifth space tourist and the second Hungarian in space.

"There is a similarity between the telescope and these two guys," said Suzanne Jacoby, a project spokesperson. "It's very innovative and the technology is very cool. It appeals to technologically minded people."


NEO News (now in its fifteenth year of distribution) is an informal compilation of news and opinion dealing with Near Earth Objects (NEOs) and their impacts. These opinions are the responsibility of the individual authors and do not represent the positions of NASA, Ames Research Center, the International Astronomical Union, or any other organization. To subscribe (or unsubscribe) contact For additional information, please see the website If anyone wishes to copy or redistribute original material from these notes, fully or in part, please include this disclaimer.

10 January 2008

Update: Chance of 2007 WD5 Impacting Mars now at 1 in 10,000

Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid.

Update from JPL NEO...

Since our last update, we have received numerous tracking measurements of asteroid 2007 WD5 from four different observatories. These new data have led to a significant reduction in the position uncertainties during the asteroid's close approach to Mars on Jan. 30, 2008. As a result, the impact probability has dropped dramatically, to approximately 0.01% or 1 in 10,000 odds, effectively ruling out the possible collision with Mars.

Our best estimate now is that 2007 WD5 will pass about 26,000 km from the planet's center (about 7 Mars radii from the surface) at around 12:00 UTC (4:00 am PST) on Jan. 30th. With 99.7% confidence, the pass should be no closer than 4000 km from the surface.

Link: JPL NEO Article

09 January 2008

Chance of 2007 WD5 Hitting Mars Reduced

Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid.

From the NASA JPL NEO site...

We have updated the orbit of 2007 WD5 using new observations from the 3.5-meter telescope at the Calar Alto Observatory in Spain. This update also incorporates refinements to the Sloan precovery observations mentioned previously. While the best estimate of close approach distance remains steady at about 30,000 km, the uncertainty in position at the close approach has decreased by a factor of three. As a result, the impact probability estimate has fallen to 2.5%, or 1-in-40 odds. If the estimated miss distance remains stable in future updates, the impact probability will continue to fall as continuing observations further constrain the uncertainties.

Link: NASA JPL NEO Site Story

From the article...

The space rock, an asteroid called 2007 WD5, is now expected to miss Mars by about 18,641 miles (30,000 km), according a Tuesday report by NASA's Near Earth-Object (NEO) program office.

Scientists now estimate the space rock's odds of walloping Mars on Jan. 30 at 2.5 percent, about a 1-in-40 chance, after a series of observations taken by astronomers using Spain's 11.5-foot (3.5-meter) Calar Alto Observatory. The new analysis lowered the asteroid's odds of a martian impact from a 3.6 percent chance released last week.

"Asteroid's Chances of Smacking Mars Dip"
08 January 2008
Tariq Malik
08 January 2008

Link: article

04 January 2008

2007 WD5 Spoof Article: "NASA plans to blow up Mars if asteroid misses"

From the article:

NASA officials announced today that if the asteroid currently heading towards Mars fails to strike, they plan on blowing the planet up with nuclear weapons themselves.

"We are all psyched up for a big explosion", said NASA administrator Michael Griffin. "If the asteroid doesn't hit then the American people will be disappointed. Therefore, we will send a small part of our nuclear arsenal to the red planet so we can see the big Kaboom!"

Astronomers says that the chance of an asteroid hitting Mars on January 30th have been increased from 1-in-75 to 1-in-25. This has excited everyone from scientists to backyard astronomers to the average joe."

"If we see an asteroid crash into Mars it will increase our understanding of what would happen when one crashes into the Earth. And that will definitely happen someday!" said Princeton astronomer James Binney. "Personally I would like to see a big hole blown into the planet. I think that would be cool".

"I would love to see Mars blow up", said Martin Frisby, a homeless Los Angeles transient. "I just don't want to be standing next to it when it happens".

US President George W. Bush said he has three high-speed nuclear weapons pointed at the red planet. He also warned that the missiles may misfire and hit Iran. In that case, he claimed, "it's not our fault".

"NASA plans to blow up Mars if asteroid misses"
31 December 2007

Link: Spoof Article

03 January 2008

2007 WD5 Impact Probability Updated (About 1 in 28)


Additional position observations for asteroid 2007 WD5 taken on December 29 through January 2 have been used to improve the accuracy of the asteroid's orbit. As a result, the range of possible paths past Mars has narrowed by a factor of 3 and the most likely path has moved a little farther away from the planet, causing the Mars impact probability to decrease slightly to 3.6% (about one chance in 28).

"New Observations Slightly Decrease Mars Impact Probability"
Don Yeomans, Paul Chodas and Steve Chesley
NASA/JPL Near-Earth Object Program Office
02 January 2008

Link: JPL NEO News Item from 02 January 2008

02 January 2008

2007 WD5 (potential Mars impactor): Updates


The impact probability for a collision of asteroid 2007 WD5 with Mars on January 30 has increased from 1.3% to 3.9%.

Pre-discovery observations of asteroid 2007 WD5, taken on November 8, 2007 have allowed its orbit to be refined and the uncertainties for the late January Mars encounter have been improved. The impact probability resulting from the recent orbit refinement has increased to a surprising 3.9% (about 1 in 25 odds). The uncertainty region during the Mars encounter now extends over 400,000 km along a very narrow ellipsoid that is only 600 km wide. Since the uncertainty region intersects Mars itself, a Mars impact is still possible. However, the most likely scenario is that additional observations of the asteroid will allow the uncertainty region to shrink so that a Mars impact is ruled out. In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes.

"Mars Impact Probability Increases to 4 Percent"
Don Yeomans, Paul Chodas and Steve Chesley
NASA/JPL Near-Earth Object Program Office
December 28, 2007

Link: JPL NEO Site story on 2007 WD5

Link: Wikipedia entry for 2007 WD5
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.