The 3200 Phaethon asteroid annually pops up in the news around December — and there’s a good reason for that. The end of the year treats stargazers to one of the best meteor showers they can hope to enjoy — the Geminids — which incidentally is created by this peculiar asteroid.
An Asteroid Oddball
According to CNET, 3200 Phaethon is one of the few asteroids known to bring on a meteor shower. In fact, until its discovery in 1983, astronomers were convinced that only comets can produce this type of dazzling space debris — which lights up in our atmosphere and streaks across the sky as shooting stars.
But this is not the only thing that makes 3200 Phaethon so unusual. Aside from the fact that it rains meteors down at Earth, this small space rock — which measures just 3.1 miles across — looks and behaves more like a comet than an asteroid.
On top of that, it sports a bizarre blue color that makes it one of the rarest asteroids in the solar system.
Its puzzling features, which seem to blur the line between comets and asteroids, have earned it the nickname of “rock comet.” Only one other object like it exists in our solar system — a small blue asteroid that goes by the name of 2005 UD — and scientists are wondering whether the two space rocks could be related.
New research suggests the "rock comet" is weirder than previously thought.https://t.co/cZqFP2srLO
— CNET News (@CNETNews) October 23, 2018
The strange case of 3200 Phaethon has fascinated astronomers for a long time. And, while a lot of interesting facts on the blue space rock have surfaced over the past three decades, a new investigation into its characteristics unveiled new puzzling things about the oddball asteroid.
The research — led by Teddy Kareta of the Lunar and Planetary Laboratory at the University of Arizona — revealed that 3200 Phaethon is “even more enigmatic” than we previously imagined, reports Phys.org.
Almost A Comet
After looking at data from two different telescopes — NASA’s Infrared Telescope Facility on Mauna Kea in Hawaii and the Tillinghast telescope at the Smithsonian Astrophysical Observatory in Arizona — the scientists uncovered that the asteroid’s orbit brings it unusually close to the sun.
During these close encounters, the surface of the space rock heats to a whopping 1.500 degrees Fahrenheit (800 degrees Celsius) — hot enough to melt aluminum.
“It’s a weird blue asteroid that created the Geminids and gets so hot that metals on the surface turn to goo,” said Kareta.
Speaking yesterday at the 50th annual meeting of the American Astronomical Society Division for Planetary Sciences in Knoxville, Tennessee, Kareta pointed out that — whenever it gets close to the sun — 3200 Phaethon appears to exhibit a comet-like tail.
This is because the extreme temperatures near the sun make the asteroid crack — “similar to a dry riverbed cracking in the afternoon heat.” As a result, 3200 Phaethon releases a tiny dust tail that looks suspiciously like the coma of a comet.
As a matter of fact, when it was first discovered, 3200 Phaethon was initially mistaken for a comet.
“At the time, the assumption was that Phaethon probably was a dead, burnt-out comet,” said Kareta, “but comets are typically red in color, and not blue. So, even though Phaeton’s highly eccentric orbit should scream ‘dead comet,’ it’s hard to say whether Phaethon is more like an asteroid or more like a dead comet.”
Blue asteroids are rare, and blue comets are almost unheard of. An international team investigated (3200) Phaethon, a bizarre asteroid that sometimes behaves like a comet, and found it even more enigmatic than previously thought https://t.co/vPOoMnB0bQ pic.twitter.com/K4gbEloDhZ
— Massimo (@Rainmaker1973) October 24, 2018
The only other asteroid known to behave in the same way is 2005 UD. Kareta’s team is currently studying the tiny space rock, which is often referred to as a “mini-Phaeton,” to see whether these blue asteroids share other properties as well.
Astronomers speculate that both 3200 Phaethon and 2005 UD might have splintered from the same “parent” space rock — a giant blue asteroid known as 2 Pallas. This enormous object lies in the Asteroid Belt between the orbits of Mars and Jupiter and is one of the biggest space rocks in our solar system — after Ceres and 4 Vesta.
The ‘Bluest’ Asteroid
Only a fraction of known asteroids exhibits the blue color seen in 3200 Phaethon, 2005 UD, and 2 Pallas. But 3200 Phaethon really stands out among them as the “bluest” asteroid in this small crowd, Kareta discovered.
Similar to other blue asteroids and comets, 3200 Phaethon reflects more light in the blue part of the spectrum, the Inquisitr previously reported. But the space rock seems to don a deeper shade of blue — and is actually quite dark, with a surprisingly uniform surface.
“Interestingly, we found Phaethon to be even darker than had been previously observed, about half as reflective as Pallas,” explained Kareta. “This makes it more difficult to say how Phaethon and Pallas are related.”
The astronomer hopes to get more answers in the future, once the Japanese DESTINY+ mission takes off to study the mystifying asteroid. Scheduled to launch in 2022, the mission will chase 3200 Phaethon for about three years, finally arriving in its orbit sometime in 2025.