Spooky Skull Asteroid Flyby

This Halloween, we were in for a treat—from our Universe! The asteroid 2015 TB145 passed by the Earth yesterday around 1pm Eastern Time (EDT) at a range of 480,000 km from the Earth. Scientists suggest that it might have actually been a dead comet, and in the spirit of Halloween, guess what it looked like? That's right, a skull!

Photo credit: NAIC-Arecibo/NSF (space.com)

This image was captured with radar using NASA's Infrared Telescope Facility (IRTF) in Mauna Kea, Hawaii. When it was originally spotted on October 10, 2015, scientists thought it was a large asteroid with a unique and wide orbit. However, based on data gathered on October 30, 2015 by IRTF, scientists predicted the asteroid was actually a dead comet. The data revealed an interesting orbit which is similar to that of a comet instead of an asteroid. The data also suggests that 2015 TB145 shed all of its volatiles after many orbits around the sun, hence why it no longer has its bright tail.

A research scientist at the Planetary Science Institute (Tucson, Arizona) stated: "We found that the object reflects about six percent of the light it received from the sun. That is similar to fresh asphalt, and while here on Earth, we think that is pretty dark, it is brighter than a typical comet which reflects only 3 to 5 percent of the light. That suggests it could be cometary in origin—but as there is no coma evident, the conclusion is that it is a dead comet."

By analyzing new measurements, scientists could see that 2015 TB145 is much darker than they had previously thought. Since comets are usually darker than asteroids, all the evidence yields more towards the conclusion that 2015 TB145 is indeed, a comet (that is dead).

Thanks to the radar images, 2015 TB145 also turned out to be larger than it was previously thought. 2015 TB145 is also 2,000 feet wide (that's the size of 5 and 1/2 football fields) while rotating once every five hours at 126,000 km/h. If it came towards the Earth, it would have created a 6 mile wide crater!

There was so much that was learned by 2015 TB145's flyby. Thanks to the observations, collected data, and analysis's, scientists now have an updated knowledge of asteroids and comets for future study. It turns out the creepy asteroid was kind to us after all. It helped scientists prepare for future threats of celestial bodies coming towards the Earth!

Sources:

1) http://astronomynow.com/2015/10/31/skull-shaped-halloween-close-fly-by-object-is-likely-a-dead-comet/

2) http://www.space.com/30980-halloween-asteroid-flyby-a-science-treat.html

3) http://www.iflscience.com/physics/huge-asteroid-set-fly-past-earth-today-actually-dead-comet-and-it-looks-just-skull