The view of Vesta in Dawn’s rear view mirror.
The view of Vesta in Dawn’s rear view mirror.
Tag: asteroids
Engineers have now confirmed that Dawn has left the gravitational sphere of Vesta and is officially on its way to Ceres.
Engineers have now confirmed that Dawn has left the gravitational sphere of Vesta and is officially on its way to Ceres.
Do you want to name an asteroid that might hit the Earth? NASA has a contest for students to do just that.
Do you want to name an asteroid that might hit the Earth? NASA has started a contest for students to do just that.
Dawn’s farewell tour of the giant asteroid Vesta
An evening pause: As Dawn begins its journey away from Vesta, the science team has put together this stunning video tour of the giant asteroid.
The mysterious dark streaks on Vesta
In a preprint paper published today at the Los Alamos astro-ph website, scientists have taken a detailed look at the mysterious dark streaks seen by Dawn on the surface of the asteroid Vesta and have concluded that the material comes from impacts, not from volcanic activity.
The scientists also concluded that
the majority of the spectra of [dark material] are similar to carbonaceous chondrite meteorites mixed with materials indigenous to Vesta.
Carbonaceous chondrite meteorites are considered to be the most primeval material in the solar system. This means that Vesta has the potential to give scientists a convenient laboratory for studying that primeval material and the early formation of the solar system. Ideally, the best way to do this would of course be to go there.
The scientists also theorize that much of this material was brought to Vesta by a single large impact.
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An update on Dawn’s reaction wheel failure.
An update on Dawn’s reaction wheel failure.
Essentially, this will delay the journey to Ceres for about nine days. The spacecraft is left with two working reaction wheels, with which it can complete all its science work. However, if they cannot get the failed wheel working again, Dawn will be left with no backup should another wheel fail.
One of Dawn’s reaction wheels, used to orient the spacecraft, shut down last week.
Uh-oh: One of Dawn’s reaction wheels, used to orient the spacecraft, shut down last week.
During a planned communications pass on Aug. 9, the team learned that the reaction wheel had been powered off. Telemetry data from the spacecraft suggest the wheel developed excessive friction, similar to the experience with another Dawn reaction wheel in June 2010. The Dawn team demonstrated during the cruise to Vesta in 2011 that, if necessary, they could complete the cruise to Ceres without the use of reaction wheels.
That the spacecraft can get to Ceres without reaction wheels is good. However, can it be oriented precisely to do science without these wheels? The JPL press release does not say.
Dawn has begun its slow departure from Vesta in anticipation of its journey to the solar system’s largest asteroid, Ceres.
Dawn has begun its slow departure from Vesta in anticipation of its journey to the solar system’s largest asteroid, Ceres.
The departure was actually announced two weeks ago, but since this is a very slow process it isn’t like we have missed anything. Dawn’s ion engines are very efficient, but they work at a very leisurely pace. It will take a month for the engine’s thrusters to push Dawn out of its orbit around Vesta.
New computer models suggest that the Moon was created when a Mars-sized asteroid hit the Earth in a head-on collision at high speed, not a glancing blow at relatively slow speeds, as previously thought.
New computer models suggest that the Moon was created when a Mars-sized asteroid hit the Earth in a head-on collision at high speed, not a glancing blow at relatively slow speeds, as previously thought.
Watching a big asteroid zip past the earth, live
Watching a big asteroid zip past the earth, live.
The only program surveying the southern sky for dangerous asteroids has lost its funding and will end this month.
The only program surveying the southern sky for dangerous asteroids has lost its NASA funding and will end this month.
Scientists have identified the oldest known impact crater on Earth, three billion years old.
Scientists have identified the oldest known impact crater on Earth, three billion years old.
A private organization focused on preventing asteroids from impacting the Earth today announced its plans to build and launch an infrared space telescope by 2017.
A private organization focused on preventing asteroids from impacting the Earth today announced its plans to build and launch an infrared space telescope by 2017.
Scientists have found a previously unknown mineral embedded in a meteorite that crashed to Earth in 1969.
Scientists have found a previously unknown mineral embedded in a meteorite that crashed to Earth in 1969.
Dubbed panguite, the new titanium oxide is named after Pan Gu, the giant from ancient Chinese mythology who established the world by separating yin from yang to create the earth and the sky. … “Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science,” says Chi Ma, a senior scientist and director of the Geological and Planetary Sciences division’s Analytical Facility at Caltech and corresponding author on the paper.
An asteroid that was discovered only four days before it flew by the Earth on June 14 has turned out to be much bigger than first thought.
An asteroid that was discovered only four days before it flew by the Earth on June 14 has turned out to be much bigger than first thought.
This particular asteroid may not have been a danger, but much of the concern was rooted in the late warning of its detection — 2012 LZ1 was spotted only four days before closest approach. One of the reasons for its late discovery is because it was detected in Southern Hemisphere skies, part of the world were we have few asteroid-watching programs. If it had been on a collision course with Earth, a few days notice is no time at all.
So, in the aftermath of the flyby, astronomers at the famous Arecibo Observatory in Puerto Rico used radar to image the interplanetary interloper (pictured top). What they uncovered was a surprise: Asteroid 2012 LZ1 is actually bigger than thought… in fact, it is quite a lot bigger. 2012 LZ1 is one kilometer wide (0.62 miles), double the initial estimate.
Astronomers have videotaped the fly-by of a 23-foot-wide asteroid as it zipped past the Earth on May 29 at a distance of only about 12,000 miles.
Astronomers have videotaped the fly-by of a 23-foot-wide asteroid as it zipped past the Earth on May 29 at a distance of only about 12,000 miles. The video is below the fold.
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Scientists have concluded that a 460 foot diameter asteroid only has a 1 percent chance of hitting the Earth in 2040.
O goody: Scientists have concluded that a 460 foot diameter asteroid only has a 1 percent chance of hitting the Earth in 2040.
Observations to date indicate there is a slight chance that AG5 could impact Earth in 2040. Attendees expressed confidence that in the next four years, analysis of space and ground-based observations will show the likelihood of 2011 AG5 missing Earth to be greater than 99 percent.
It appears that they won’t really be able to pin down the impact odds for 2040 until 2023, when the asteroid passes the Earth at a distance of 1.1 million miles.
Watch an asteroid a third of a mile across zip past the Earth tonight.
Watch an asteroid a third of a mile across zip past the Earth tonight.
A global view of Vesta
The accumulating data from Dawn has now allowed scientists to compile a global picture of the varied surface makeup of the asteroid Vesta.
The colors were chosen to highlight differences in surface composition that are too subtle for the human eye to see. Scientists are still analyzing what some of the colors mean for the composition of the surface. But it is clear that the orange material thrown out from some impact craters is different from the surrounding surface material. Green shows the relative abundance of iron. Parts of the huge impact basin known as Rheasilvia in Vesta’s southern hemisphere, for instance, have areas with less iron than nearby areas.
It also makes for a very nice image of the giant asteroid.
The scientists building a space probe to go to asteroid 1999 RQ36 have better pinpointed its orbit.
The scientists building a space probe to go to asteroid 1999 RQ36 have better pinpointed its orbit.
Knowing this asteroid’s orbit is not only important for planning the mission. 1999 RQ36 has a 1in a 1000 chance of hitting the Earth in 2182.