Scientists Think They've Solved The Mystery of Asteroid Ryugu's Origin

The Hayabusa 2 was launched by the Japanese Space Agency. It studied the asteroid for over a year after it arrived. Hayabusa 2 sent four rovers to the asteroid.

In December 2020, it flew past Earth and dropped off a sample.

The scientific results from that mission might be the most interesting one, as they might not be an asteroid. It could be a remnant of a comet.

The Hayabusa 2 mission showed that an asteroid is a rubble pile. It is a conglomeration of smaller rocks instead of being one large chunk of rock.

It is shaped like a spinning top. This shape was forged by the asteroid's rapid rotation.

The authors say that a catastrophic collision between larger asteroids and the subsequent slow accretion of collisional debris is a widely accepted formation scenario.

Astronomers assumed that Ryugu was an asteroid since it was discovered in 1999, and a lot of the evidence supported that idea.

One thing that stood out was the fact that the asteroid definition did not include a high concentration of organic matter.

If there is a rubble pile asteroid created from the collision of two smaller asteroids, why does it have so much concentrated organic matter?

That question is at the center of a new study published in The Astronomical Journal Letters.

According to the authors, rubble-pile asteroids could be former comets, as well as the remnant of a comet. Astronomers call these objects comets.

There are comets in the far reaches of the Solar System. Unlike asteroids, which are all rock, comets are icy and contain rock and volatiles. The volatiles are mostly water ice, but comets also contain frozen carbon dioxide, ammonia, methane, and carbon monoxide. Astronomers call them dirty snowballs.

The atmosphere of comets is unbound. They sublimate into space when they approach the Sun because of the warmth. Dust and volatile gases can be found in the atmosphere.

Some comets have lost their volatiles to space after passing close to the Sun. What is left is rock. They are sometimes called extinct comets.

Is it possible that a former comet can account for the characteristics of a person?

Lead author Miura said in a press release that the comet's nucleus loses mass and shrinks, which increases its speed of rotation.

The high organic matter content can be explained by the extinct comet hypothesis. CO, CO 2, methanol, carbonyl sulfide, formaldehyde, formic acid, methane, and cyanate are some of the organic molecules detected.

The icy components of comets are thought to contain organic matter. The organic materials would be deposited on the rocky debris.

The paper states that comets have the same organics as carbonaceous chondrite asteroids, but they are concentrated on the surface.

The hypothesis was tested with simulations. They calculated how long it would take for Ryugu to become a rocky remnant. The increase in speed needed to shape the asteroid into what it is today was calculated.

The study says that the scenario is consistent with the evolution of modern.

The study focuses on asteroids with three characteristics: spinning top-shaped, rubble-pile composition and high concentration of organics. The results show that the asteroids are comet-asteroid transition objects.

The small objects that were once active comets have become extinct and are indistinguishable from asteroids.

Hayabusa 2 returned its samples to Earth, and another mission will soon do the same. The OSIRIS-REx will return its samples to Earth in three years. The samples should be analyzed to see if they are asteroids or CATs.

The article was published by Universe Today. The original article is worth a read.