Hubble Captures Interstellar Comet Borisov Whizzing Through Solar System (Photo Credit: spacetelescope.org)
Hubble Space Telescope, which belongs to the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA), has recently captured a comet 2I/Borisov streaking through our solar system on its way back into interstellar space. Borisov, the only second interstellar object known to have passed through the Solar System, is one of the fastest comets ever seen.
In a statement, spacetelescope.org said, “The image is Hubble’s revisit observation of the comet near its closest approach to the Sun. There it was subjected to a greater degree of heating than it had ever experienced, after spending most of its life in the extreme cold of interstellar space.”
“The comet is 298 million kilometres from Earth in this photo, near the inner edge of the asteroid belt. The nucleus, an agglomeration of ices and dust, is still too small to be resolved. The bright central portion is a coma made up of dust leaving the surface. The comet will make its closest approach to Earth in late December, when it will be at a distance of 290 million kilometres,” it added.
It is worth mentioning here that back in October this year, Hubble snapped the comet at a distance of approximately 420 million kilometres from Earth. The image showed the comet in front of a distant background spiral galaxy (2MASX J10500165-0152029). The galaxy’s bright central core is smeared in the image because Hubble was tracking the comet. Borisov was approximately 326 million kilometres from Earth in this exposure. Its tail of ejected dust streaks off to the upper right.
“Hubble gives us the best measure of the size of comet Borisov’s nucleus, which is the really important part of the comet,” said David Jewitt, a professor of planetary science and astronomy at the University of California Los Angeles, whose team has captured the best and sharpest images of this first interstellar 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,” he added.
Crimean amateur astronomer Gennady Borisov discovered the comet on 30 August 2019.