Astronomers will be getting an unexpected treat this Halloween, as a newly discovered asteroid will zoom by Earth on Oct. 31. Some scientists are calling the football-field sized asteroid 2015 TB145 "Spooky" in honor of All Hallows' Eve — or possibly because of the spine-tingling notion that the potentially dangerous near-Earth object was discovered only few weeks ago on Oct. 10. Instead of giving the space rock an eerie-sounding moniker, NASA has taken the "Peanuts" approach, referring to the asteroid as "The Great Pumpkin."
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2015 TB145 won't be visible to the naked eye on Halloween, but if you're seeking science over candy bars, you can watch live feeds hosted by the Virtual Telescope Project and Slooh. What makes 2015 TB145 an extra spooky treat for the Halloween season is its potential for disaster. According to Slooh, "2015 TB145 is possibly 32 times the size of the asteroid that injured a thousand people in Chelyabinsk, Siberia in 2013. If it were to impact us, the energy released would be measured not in kilotons like the atomic bombs that ended World War Two, but in H-Bomb type megatons." So, the asteroid is smaller than the one that killed the dinosaurs, but big enough to pretty much ruin Halloween forever.
Fortunately, the space rock won't hit us. It will fly by at a distance of 300,000 miles, which is greater than the distance from Earth to the moon (238,000 miles).
The asteroid was first detected by the University of Hawaii's Panoramic Survey Telescope and Rapid Response System (Pan-STARRS-1), which is affiliated with NASA JPL's Near Earth Observation Program (NEOO). The NEOO program states that the next space rock to travel as near to Earth as "Spooky" will be asteroid 1999 AN10 in 2027, which will actually come closer than 2015 TB145. 1999 AN10 will squeak by at roughly a single lunar distance. So, we don't have to worry about another near-Earth object (NEO) crashing our holiday parties for another 12 years at least — unless researchers find another previously unknown asteroid.
This is a graphic depicting the orbit of asteroid 2015 TB145 in the light blue line. The asteroid will safely fly past Earth slightly farther out than the moon's orbit on Oct. 31 at 1:05 p.m. EDT. (Photo: NASA/JPL-Caltech)
While it's spooky to think of "Spooky" making impact, scientists are enjoying the unexpected Halloween surprise and what data it might contribute to their research. Scientists at several observatories will be keeping an eye on the asteroid, tracking it and observing its features.
However, some scientists posit that perhaps the Halloween asteroid is not an asteroid at all but rather a comet. Because 2015 TB145 will be traveling close by Earth, scientists will have the opportunity to analyze the object by bouncing radio waves off of it, and they will hopefully be able to discover more about its nature. JPL's Lance Benner notes that "The Great Pumpkin" is already known to have a strange orbit. "The asteroid's orbit is very oblong with a high inclination to below the plane of the solar system…Such a unique orbit, along with its high encounter velocity — about 35 kilometers or 22 miles per second — raises the question of whether it may be some type of comet. If so, then this would be the first time that the Goldstone radar has imaged a comet from such a close distance."
So, this asteroid won't go bump in the night — but it will come relatively close, and in doing so offer scientists insight into NEOs. Additionally, if astronomy-loving Halloween enthusiasts have anything to say about it, perhaps we will see a bunch of "Spooky asteroid" costumes parading the streets on Oct. 31.