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NASA’s Spitzer Space telescope Witnesses Asteroid Smashup

asteroid collision

Image credit: Artist’s conception of asteroid collision in dust disc around the star NGC 2547-ID8. Credit: NASA/JPL-Caltech

With help of NASA’s Spitzer Space Telescope, scientists have possibly identified a collision between two asteroids which are orbiting along a young star. As a result, the dust and rocks caused by such impact could finally accumulate and create a rocky planet.

From previous observations, extremely dusty conditions from similar events have been watched by scientists; however this is the first time that they have obtained the images before and after the events. The study of present observations has been released in the journal of Science.

The possible impact took place near the star NGC 2547-ID8, 1,200 light-years away in the constellation Vela. With the history of 35 million years, the star was observed to take possible planetary formation as dust was being accumulated.

In order to know better about the primary stages of planetary formation, astronomers were intended to use Spitzer for regular observations of the star, which was started early in May 2012.

Unluckily, in August of that year, Earth was in the position behind the Sun, therefore it was impossible to make the observations. In January 2013, as scientists could look back at NGC 2547-ID8, they found the accumulation of dust, which gave the clue that the collisions between asteroids had occurred.

Talking of their study, Huan Meng, the lead author said that they thought two big asteroids smashed with each other, producing a very large cloud of grains which were sized like the very fine sand that were crashing themselves into smithereens and gradually getting away from the star.

Some rocky planets like Earth take shape as discs of dust turn around a young star quickly. When bits of dust smash into each other, they would come together and become bigger in a progressive way. Exactly like snowflakes crashing together to generate the dense, tightly-packed snowballs, planets could be produced from dust being forced together. As bigger objects such as asteroids or proto-planets crash, a very large amount of dust and debris would be created. Actually, most people think Moon was formed out of the debris caused by the collision between the proto-Earth and a planetary body, which was similar to the size of Mars.

According to Kate Su, the co-author of the paper, in addition to the fact that they witnessed what seemed to be the wreckage of a huge smashup, his group also was capable of identifying how it was changing, because the signal was fading when the cloud destroyed itself through grinding its grains down so as to escape from the star. To the eyes of Kate Su, Spitzer was thought to be the best telescope to monitor stars regularly and precisely to look at the small changes in infrared light over months and even years.

It was unfortunate that the scientists’ observations were within limitation due to vantage point of the Earth. Even if the Sun was not in the way, the orientation of the dusty, prolonged cloud which encircled the star could interfere with data collection.

When the short end of the cloud was being observed, the amount of infrared light that Spitzer was able to pick up was limited and unclear. However more infrared light could be seen when the longer sides were facing Earth. By studying data from these infrared fluctuations, astronomers would be able to better understand about these types of collisions as well as  rocky planetary formation.

As George Rieke, another co-author said, they were closely watching rocky planet formation which occurred right before them. It should be rare opportunity to study this process in near real-time.

Source: NASA Jet Propulsion Laboratory

Journal reference: Meng, Huan YA, et al. “Large impacts around a solar-analog star in the era of terrestrial planet formation.” Science 345.6200 (2014): 1032-1035.