Looking at the night sky, the casual observer would consider a “shooting star” to be a lucky sighting. But recently, NASA scientists have seen something even more incredible: an asteroid with six tails. Initially, the lights streaming from the asteroid confused researchers. But on September 23, NASA’s Hubble telescope photographed the asteroid again, and that’s when lead investigator and University of California Los Angeles professor David Jewitt was blown away.
“We were literally dumbfounded when we saw it.” Jewitt said. “Even more amazing, its tail structures change dramatically in just 13 days as it belches out dust.”
This asteroid, known as P/2013 P5 has been described as “weird and freakish” and with good reason. P/2013 P5 has six tails, while the average asteroid has only one. And scientists weren’t entirely sure what the tails are made of.
“One idea was that we were seeing ice on the asteroid outgassing, but the object is too hot, around 170 Kelvin, for ice.” said Jewitt. However, there now seems to be a consensus that the asteroid is spewing dust.
In a study published in The Astrophysical Journal Letters, Jewitt, Agarwal, et. al, believe the asteroid is “losing mass through a rotational instability.” This may be a result of thousands of years of pressure from the Sun’s light, pressure that may eventually cause the asteroid’s weak gravity to fail. If that happens, the asteroid may shatter.
However, the asteroid is currently about 480 meters in diameter and it has already lost 100 to 1000 tons of dust in its orbit. But even if it does collapse, astronomy fans have nothing to fear.
“In astronomy, where you find one, you eventually find a whole bunch more,” Jewitt said. “This is just an amazing object to us, and almost certainly the first of many more to come.”