Ryugu is an unusual space object. It resembles a typical asteroid, shaped like a top toy. But there is one detail that distinguishes it from other asteroids – a high concentration of organic matter inside.
A study by Japanese scientists from Nagoya University suggests that Ryugu may be the remnant of a special type of comet – Comet Asteroid Transition (CAT; “asteroid comet”). ScienceAlert writes about it.
Comets form in the far, cold corners of the solar system. Unlike asteroids, which are made entirely of rock, comets are also made of ice and frozen volatiles. The latter are water ice, frozen carbon dioxide, ammonia, methane and carbon monoxide.
As it approaches the Sun, the heat melts parts of comets, leaving a rocky base. According to scientists, Ryugu is one such object. Some facts point to this. For example, Ryugu spins fast. “The sublimation of ice causes the comet’s nucleus to lose mass and contract, which increases its rotation rate. As a result of this rotation, the comet’s nucleus can acquire the rotational speed necessary to form a top shape, ”the study says.