As we reported recently, a strange comet with no tail has returned after perhaps billions of years — and there’s a big reason why this is exciting to scientists.

This comet is the first of its kind — a tailless comet that may have been in the general vicinity when Earth was formed before getting blasted far away by the giant planets in our solar system. And now that it’s back, scientists think it could help us understand more about how our solar system formed and subsequently developed.

Why is that the case? It’s because the comet was believed to have been here when the solar system was early in its development. As a result, its orbit could hold tremendous clues — it was buffeted billions of years ago by the intense gravity of our solar system’s largest planets, and scientists can study that orbit for clues on what exactly happened all those years ago.

Scientists just don’t know much about how the giant planets behaved in the early solar system. Did Jupiter and Saturn live a relatively quiet early existence as they gradually settled into their current orbits, or was there a violent interaction between the planets that resulted in total chaos before the planets assumed their present position? This Manx comet, as it is called, could help scientists figure that out.

“A number of theoretical models are able to reproduce much of the structure we see in the Solar System,” ESO said in the statement. “An important difference between these models is what they predict about the objects that make up the Oort Cloud. Different models predict significantly different ratios of icy to rocky objects. This first discovery of a rocky object from the Oort Cloud is therefore an important test of the different predictions of the models. The authors estimate that observations of 50-100 of these Manx comets are needed to distinguish between the current models, opening up another rich vein in the study of the origins of the Solar System.”