Interstellar and Solar System Comets Share a Surprising Ingredient: Nickel
Cold comets — both natives and the interstellar Comet Borisov — have nickel and iron vapor in their atmospheres, and scientists want to know why.
Interstellar Comet Was Pristine Sample of Planet Formation
New analysis shows that Comet 2I/Borisov, which zipped nearest the Sun in late 2019, was unlike any comet we’ve seen before.
Can We Expect Seven Interstellar Visitors Per Year?
A new study estimates the number of interstellar objects that fly through the inner solar system every year, and it could be quite a lot.
The Origins of Interstellar Objects
The first two interstellar visitors to the solar system are finally shedding light on their places of origin.
Is the Interstellar Comet 2I/Borisov Breaking Up?
New observations of the interstellar comet — which traveled unaltered for eons before arriving in the solar system — have revealed it's fragmenting
Hubble Images Comet Borisov at Perihelion
The Hubble Space Telescope imaged the interstellar comet 2I/Borisov when it came closest to the Sun before heading back out of the solar system.
Interstellar Comet Borisov "Indistinguishable" from Solar System Comets
The solar system's newest interstellar visitor, Comet 2I/Borisov, bears a striking resemblance to the icy population of the outer solar system.
Will Amateurs Be Able to See the New Interstellar Comet?
Only the second object thus far to visit the solar system from interstellar space, Comet Borisov is expected to reach perihelion in December. What can we see now?