The Blue Space Rock is much Weirder than Previously Thought
Whether 3200 Phaethon an asteroid or a comet?
Blue Space Rock is a strange rock which was discovered in 1983 by John K. Davies and Simon F. Green. They used data from the Infrared Astronomical Satellite (IRAS) for locating this celestial object, which made 1983 TB (commonly known as 3200 Phaethon) the first asteroid to be discovered through the images captured by a spacecraft. It has a rare blue color and an extremely eccentric orbit. The name ‘3200 Phaethon’ comes from the driver of Helios’ chariot because it gets closer to the sun than any other object. The fact that it got discovered due to a spacecraft was just the beginning of its special nature as researchers found it is even weirder than they had imagined.
This mysterious rock from space made a close flyby of Earth last year, which allowed the researchers to have a closer look at it. The biggest mystery that the scientists need to solve about this rock is: whether it is a comet or an asteroid? Originally, it was believed that it is an asteroid as it looked like one but later research made things seriously complicated. 3200 Phaethon stays like a tiny speck floating through space even when it gets incredibly close to the sun. This makes it a suitable candidate for an asteroid. Having said that, the eccentric orbit of the blue space rock allows it to go closest to the sun while it out past the orbit of Mars on the other side. This kind of orbit is more typical for comets than asteroids.
Researchers got an opportunity to get some detailed knowledge about this mysterious rock on 16th December 2017, when it made its closest approach to the Earth since 1974. It came within 10.3 million kilometers of our planet and a graduate student at the University of Arizona, Teddy Kareta, made full use of that.
He led an international team of researchers who analyzed the blue space rock during that flyby. They used Tillinghast Telescope and Infrared Telescope Facility of NASA for their observations. Kareta presented the findings of his team at the 50th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences on 23rd October. His explanation may overturn a long-lasting theory according to which Phaethon is a fragment of the ‘Pallas’, a much larger asteroid. Talking about that, he said,
“However, Pallas’ albedo [or reflectivity] is about twice what we found for Phaethon’s albedo. With an albedo of about 8 percent, Phaethon is slightly brighter than charcoal and only about half as bright as Pallas.”
The Geminid Meteor Shower is another massive event which questions the idea of it being an asteroid. All meteor showers other than the Geminid occur when comets get close to the sun. Comets are icy bodies that are made up of a mixture of rock, dust, ice, and frozen gas. When they reach too close to the sun, some of their frozen material vaporizes. It leaves behind a trail of comet crumbs which are observed on Earth as meteor showers whenever our planet goes through such a trail of debris. On the other hand, asteroids behave differently to the comets and that’s the reason why scientists are not sure about the mechanism that creates Geminid every year. Kareta acknowledged that and proposed a possible explanation by saying,
“Exactly how Phaethon created that trail of debris remains a mystery. While it is possible that material swept off the asteroid’s surface could contribute to the debris, the amount of dust that gets swept off is nowhere near enough to sustain the Geminids. One possibility is that Phaethon collided with another object in space and the Geminids are the debris from that catastrophic breakup. So, in that case, you’re essentially seeing dust, which is kind of like blood splatter, to be gruesome, from this really violent event.”
Kareta also agreed to the fact that this blue space rock displays reasonable qualities of a comet. For instance, it does release a tiny tail when it gets closest to the sun. The other researchers from the University of Arizona mentioned that this creates enough doubt to blur the line between comets and asteroids. They elaborated that in the following words:
“This kind of activity has only been seen on two objects in the entire solar system — Phaeton and one other, similar object that appears to blur the line traditionally thought to set comets and asteroids apart.”
Despite this confusion, scientists are hopeful that the DESTINY+ mission of JAXA will resolve this mystery once it launches in 2022.
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