A new model of the origin of asteroids suggests that in the beginning they weren’t rubble piles but “churning balls of mud.”
A new model of the origin of asteroids suggests that in the beginning they weren’t rubble piles but “churning balls of mud.”
Tag: asteroids
Four asteroids buzzed the Earth this past week.
Chicken Little Report: Four asteroids buzzed the Earth this past week.
I suspect that the increase in detected asteroids is not because there are more of them but because our ability to detect them continues to improve.
The search to find and understand the Chelyabinsk meteorite.
The search to find and understand the Chelyabinsk meteorite.
A newly discovered asteroid will pass within the Moon’s orbit on Wednesday.
A newly discovered asteroid will pass within the Moon’s orbit on Wednesday.
2013EC, as the asteroid has been named, is estimated to be between 30 to 60 feet in diameter.
“This is the biggest meteorite found in East Antarctica for 25 years.”
The meteorite that landed in Russia on February 15 has now been traced to the Apollo family of near Earth asteroids.
The meteorite that landed in Russia on February 15 has now been traced to the Apollo family of near Earth asteroids.
New data has allowed scientists to lower the chance that the asteroid Apophis will hit the Earth in a future orbit.
New data has allowed scientists to lower the chance that the asteroid Apophis will hit the Earth in a future orbit.
Recent observations from Pan-STARRS PS1 telescope at Haleakala, Hawaii have reduced the current orbital uncertainty by a factor of 5, and radar observations in early 2013 from Goldstone and Arecibo will further improve the knowledge of Apophis’ current position. However, the current knowledge is now precise enough that the uncertainty in predicting the position in 2029 is completely dominated by the so-called Yarkovsky effect, a subtle nongravitational perturbation due to thermal re-radiation of solar energy absorbed by the asteroid. The Yarkovsky effect depends on the asteroid’s size, mass, thermal properties, and critically on the orientation of the asteroid’s spin axis, which is currently unknown. This means that predictions for the 2029 Earth encounter will not improve significantly until these physical and spin characteristics are better determined.
The new report, which does not make use of the 2013 radar measurements, identifies over a dozen keyholes that fall within the range of possible 2029 encounter distances. Notably, the potential impact in 2036 that had previously held the highest probability has been effectively ruled out since its probability has fallen to well below one chance in one million. Indeed only one of the potential impacts has a probability of impact greater than 1-in-a-million; there is a 2-meter wide keyhole that leads to an impact in 2068, with impact odds of about 2.3 in a million.
The second paragraph basically says that the keyholes that might bring Apophis back to Earth are very small, making it unlikely that the asteroid will fly through any one of them in 2029. The first paragraph however notes that it will be impossible to chart the asteroid’s course accurately enough to rule out this possibility until we have more data on the asteroid itself.
Scientists have released some results from their look at asteroid 2012 DA14 during its fly-by last week.
Scientists have released some results, including video, from their look at asteroid 2012 DA14 during its fly-by last week. Key quote:
The asteroid’s path was perturbed by Earth’s gravitational field in such a way that it won’t come as close in the foreseeable future.
The video, which I have embeded below the fold, was produced from radar data. It clearly shows the asteroid’s rotation.
» Read more
Russian scientists have identified the first fragments from Friday’s meteorite in Chelyabinsk.
Russian scientists have identified the first fragments from Friday’s meteorite in Chelyabinsk.
The pieces, found on the ice of a lake, were stony chondrites.
Largest in a century.
More on today’s Russian meteorite: Largest in a century.
My earlier skepticism appears incorrect. This impact actually happened.
Note the article’s sense of outrage and panic that we aren’t looking for these types of rocks:
Although a network of telescopes watches for asteroids that might strike Earth, it is geared towards spotting larger objects — between 100 metres and a kilometre in size. “Objects like that are nearly impossible to see until a day or two before impact,” says Timothy Spahr, Director of the Minor Planet Center in Cambridge, Massachusetts, which tracks asteroids and small bodies. So far as he knows, he says, his centre also failed to spot the approaching rock.
Yet, today’s impact actually illustrates the wisdom of excluding this kind of small asteroid from searches. They aren’t big enough to do serious harm, and trying to find them would hamper searches for larger asteroids that do pose a serious risk.
How to watch asteroid 2012 DA14 zip past the Earth today.
How to watch asteroid 2012 DA14 zip past the Earth today.
An unexpected meteorite shower yesterday across three regions of Russia has reportedly caused more than 400 people to seek medical help.
An unexpected meteorite shower yesterday across three regions of Russia has reportedly caused more than 400 people to seek medical help.
Hundreds suffered cuts from broken glass as the meteorites smashed windows in numerous buildings across the Chelyabinsk Region, officials said. “The condition of at least three [people] is considered grave,” an Interior Ministry spokesman said. At least six cities have been hit in three central regions of Russia. Some areas of neighboring Kazakhstan were also affected, Russian state officials confirmed on Friday.
There is something about this story, reported in many Russian news sources, that smells fishy to me. Something happened, and it likely is related to a shower of meteorites, but the images at the link above as well as here and here just don’t look right.