When NASA's Spitzer Space Telescope spotted a huge eruption of dust surrounding a distant star, scientists knew they were watching history in the making.
Scientists had been regularly tracking the star by the name NGC 2547-ID8 since the explosion of dust between August 2012 and January 2013. The result of that eruption? An asteroid collision, scientists say.
"We think two big asteroids crashed into each other, creating a huge cloud of grains the size of very fine sand, which are now smashing themselves into smithereens and slowly leaking away from the star," Huan Meng, lead author of a study on the collision and a graduate student of the University of Arizona, Tucson, said.
The chance to observe and collect data from the asteroid smash-up may also provide important insights into how asteroid collisions contribute to the formation of rocky planets like our own.
All rocky planets begin life as dust circling a star. Over time the dust clumps together to form various asteroids, asteroids that eventually collide and continue to reform. These over time become proto-planets. After 100 million years the rocky not quite planets mature into full-grown planets, with our Moon believed to have formed from an impact between an early Earth and a traveling Mars-size object.
A thick cloud of dust now orbits the star in the zone where rocky planets typically form. Spitzer uses infrared eyes to see far into space and observe NGC 2547-ID8, which is about 1,200 light-years away. Scientists use the infrared signals from the dust cloud, but what the signal varies depending what is visible from Earth. When the elongated dust cloud faces the Earth, the telescope captures more of the infrared signals, but when the head or tail of the cloud is in line with Earth less is observed. By studying this scientists can learn more about how planets similar to Earth form.
"We are watching rocky planet formation happen right in front of us," said George Rieke, a University of Arizona co-author of the new study. "This is a unique chance to study this process in near real-time."
Spitzer uses infrared eyes to see far into space and observe NGC 2547-ID8, which is about 1,200 light-years away. NASA turns the telescope to the star daily after observing dust variations around the start, which hints at ongoing asteroid collisions. For a terrestrial planet like our own to form, a much larger impact must eventually occur -- something that astronomers are hoping Spitzer will capture.
