Redness of Neptunian asteroids sheds light on early Solar System

[Kid Berwyn]

1. Fascinating...early solar system history.

From OP’s press release:

The redness of the asteroids implies that they contain a higher proportion of more volatile ices such as ammonia and methanol. These are extremely sensitive to heat, and can rapidly transform into gas if the temperature rises, so are more stable at large distances from the Sun.

The location of the asteroids at the same orbital distance as Neptune also implies that they are stable on timescales comparable to the age of the Solar System. They effectively act as a time-capsule, recording the initial conditions of the Solar System.

The presence of redder asteroids among the Neptunian Trojans suggests the existence of a transition zone between more neutral coloured and redder objects. The redder Neptunian asteroids may have formed beyond this transition boundary before being captured into the orbit of Neptune. The Neptunian Trojans would have been captured into the same orbit as the planet Neptune as the ice giant planet migrated from the inner solar system to where it is now, some 4.5 billion kilometres from the Sun.