NASA has just unveiled pictures of 2I/Borisov , the second known object to have ever entered our solar system coming from another part of space.
The first spotting of such an object was the Oumuamua comet, back in 2017.
The Hubble Space Telescope pictures show the comet in front of a spiral galaxy.
Crimean amateur astronomer Gennady Borisov first spotted the object in August, and named it after himself. NASA then closely tracked the comet course, as it moved closer to our planet.
The first images by the spatial telescope came in October, followed by new photographs released the two following months.
David Jewitt, a professor of planetary science and astronomy at the University of California, Los Angeles, whose team revealed the pictures, told the Independent : "Hubble gives us the best measure of the size of comet Borisov's nucleus, which is the really important part of the comet.
"Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be.
“The radius is smaller than half a kilometre. This is important because knowing the size helps us to determine the total number, and mass, of such objects in the solar system, and in the Milky Way.
“Borisov is the first known interstellar comet, and we would like to know how many others there are."
This key discovery is the first step in studying and comparing other interstellar objects, as further Hubble observations are to be led by NASA in January 2020.
