People today think that they know a lot about our solar system but only about the planets and moons. There are a vast number of smaller bodies of rock and ice floating around in space such as comets and asteroids. A planetary scientist from the University of California, David Jewitt, decided to learn more about these little objects and ended up finding a cosmic conundrum when he noticed a strange group of asteroids near Neptune.

The basics of an asteroid

Asteroids tend to range in size from pebbles to large cities and are relics of our solar system’s formation over 4.5 billion years ago. As material that was not swept up into planets, asteroids are scattered throughout our entire solar neighborhood.


One area is the Asteroid belt that orbits the sun between Mars and Jupiter but there are also others known as Trojan asteroids that occupy the same orbits as Jupiter and Neptune. These are usually seen as little groups that exist either 60 degrees behind or ahead of their host planet.

Where did they come from?

There has always been a debate about where these Trojans came from. Although they orbit both Neptune and Jupiter, the Jovian and Neptunian Trojans are believed to come from somewhere else. Many scientists think that these groups of asteroids derived from another primary location known as the Kuiper Belt which orbits the sun far beyond Neptune.


Jewitt believes a different theory. He argues that the Trojans formed near Jupiter and Neptune as the solar system formed and were caught by the gravity of the forming planets but not fast enough to become a part of that planet.

The same yet very different

The asteroids near the two planets are not like the asteroids in the Kuiper belt. These groups of asteroids have distinctly different colors than the ones in the belt according to Jewitt. The Neptunian asteroids also appear to have sunbaked surfaces like the ones near Jupiter even though they are the farthest from the sun.


This observation calls into question the origin of our solar system. Are things constantly moving? Did our planet have a different orbit? Observing and studying these Trojans may bring more questions than answers but can still shed some light on the solar system’s very beginning.