A spacecraft will be sent close to Jupiter to follow the birth step by step: to understand how a comet is born scholars have an ambitious idea
Our Solar System is full of fascinating elements. So are some planets, especially the giant ones that are farther away from us. So is our Sun, which we just “touched”. And then there are elements that often go unnoticed, and that leave us speechless when we realize their size and history.
Among these are the Centaurs, in Italian Centauri, a multitude of pieces of rock and ice as big as a medium-sized city – yes, you read that right. From them are born the famous – and mysterious – comets.
It takes a Centaur to make a comet
These space objects rotate between the orbits of Jupiter and Saturn, in the outermost part of the Solar System. Every so often, Jupiter’s gravitational force “sucks” one of them in, and pushes it into a new orbit toward the inner Solar System.
As it approaches the Sun, the sucked-in Centaur heats up, and releases some gases including water vapor, produced by the ice at the center of the Centaur. The solar wind then pushes these gases away from the object’s body, creating a distinctive tail: and that’s how a comet is born.
There have been dozens of scientific studies looking at comets, but we’ve never observed one at the moment of birth. That, however, is about to change.
An ambitious idea
The idea is from University of Chicago physicist Darryl Seligman, and was published in the scientific journal Planetary Science Journal. In short, scientists would park a spacecraft near Jupiter, ready to follow whatever Centaur is hurled toward the inner Solar System – as if hitchhiking or asking for a ride.
“Such a study would be hugely important not only to really understand how a comet is born,” Seligman explains, “but also to see what water looks like at such a great distance from the Sun, and how it behaves.”
Seligman has even already identified a potential object to follow: it’s Centaur P/2019 LD2 (ATLAS), or LD2 to its friends. It is about 12km in diameter, like Staten Island in the United States, and has a 12-year solar orbit, staying close to Jupiter. According to studies, LD2 will have a close encounter with Jupiter – and thus a potential “boost” – in 2063. So Seligman expects his spacecraft to launch a couple of years earlier, in 2061.