According to NASA, comets are “cosmic snowballs of frozen gases, rock and dust that orbit the sun … When a comet's orbit brings it close to the sun, it heats up and spews dust and gases into a giant glowing head larger than most planets.”
— W. M. Keck Observatory (@keckobservatory) November 26, 2019
The image taken by astronomers show the comet’s tail, which is almost 100,000 miles long - roughly 14 times the size of Earth. The images were captured on November 24 using the W.M. Keck Observatory’s Low-Resolution Imaging Spectrometer in Hawaii.
“It’s humbling to realize how small Earth is next to this visitor from another solar system,” Pieter van Dokkum, one of the astronomers involved in the project, said in a statement.
The release also states that the comet was first seen in the summer and is presently moving toward Earth. It is expected to be about 190 million miles from Earth in early December.
The comet is believed to have formed in a “solar system beyond ours” and then “ejected into interstellar space as a consequence of a near-collision with a planet in its original solar system.”
Astronomer Gregory Laughlin also noted in the release that the comet is emitting “gas and fine dust” as it approaches Earth.
“Astronomers are taking advantage of Borisov’s visit, using telescopes such as Keck to obtain information about the building blocks of planets in systems other than our own,” Laughlin said.
An October study submitted to The Astrophysical Journal Letters suggests that Comet 2I/Borisov is carrying water on it. If that is the case, that would be the first time that water beyond the solar system has been found.
Borisov is only the second known interstellar object to pass through our solar system following the 2017 detection of ‘Oumuamua.