A Comet From Another Star Hints That Our Solar System Isn't One-Of-A-Kind
"A comet from another star will swing by our sun Dec. 8."
"Known as 2I/Borisov, it is the first comet to ever be seen coming from interstellar space. But despite its alien origins, astronomers say it actually looks pretty familiar."
"'Borisov is a comet very like what we have in our own solar system,' says Michele Bannister, a planetary astronomer at Queen's University Belfast told NPR's Short Wave. Whatever planetary system it formed in, 'it's a lot like our own.'"
"Borisov was first spotted by an amateur astronomer named Gennady Borisov back in August. Professionals quickly followed up and established that the comet was not from our neighborhood. Many of the solar system's comets reside in the so-called Oort Cloud, a region many thousands of times farther out from the sun than Earth's orbit. Borisov, by contrast, is coming in from deep space."
"Ye Quanzhi of the University of Maryland is one of many astronomers trying to figure out where the heck it came from. He and his colleagues have been looking at photos of the comet, trying to trace its trajectory, and thus work out the last star it visited."
"'The Universe is big, so we can only speculate,' Ye says."