Previously this year, a comet that reached into our Solar System from a distant star, seemed to have found its end when it began to break apart.
But astronomers have good news. A new analysis of interstellar Borisov has discovered that its main body will survive. Here are the latest details.
Interstellar Comet Borisov Re-examined
2I/Borisov blasted onto the scene in August 2019, when it was officially discovered for the first time. The comet was zipping through the Solar System at a trajectory that showed an interstellar origin – making it the second found interstellar visitor and the first interstellar comet.
Then, Borisov reached perihelion, the closest level to our host star, in December 2019 and continued its path bending slightly because of the Sun’s gravity. This year, however, it began acting up. Astronomers observed an increase in brightness, due to some outbursts of ice and dust that were “strongly indicative of an ongoing nucleus fragmentation.” It wasn’t until late March when the Hubble Space Telescope confirmed that the Borisov comet was in two pieces.
“Our observations reveal that the outburst and splitting of the nucleus are minor events involving a negligible fraction of the total mass,” explained the researchers in a new paper.
It’s not unusual for comets from the outer Solar System to deteriorate after perihelion. It’s believed that ices in the comet sublimate, which increases the comet’s spin. Also, there is the added torque that speeds up the centripetal instability, which triggers the comet to die.
Astronomers have been keeping track of the interstellar comet Borisov; so far, no other outbursts have been noticed, showing that our visitor remained calm, and survived the pressures of perihelion. Borisov has many chances to survive its passage through the planetary region, mainly unscathed. We’re going to find out more in the following weeks when another paper will be published.