The NASA/ESA Hubble Space Telescope has captured an amazing new photo of 2I/Borisov, the first known interstellar comet ever identified.
On October 12, 2019, Hubble observed the interstellar comet 2I/Borisov at a distance of approximately 261 million miles from Earth. Image credit: NASA / ESA / Hubble / D. Jewitt, University of California, Los Angeles.
2I/Borisov, also known as C/2019 Q4, was discovered by Ukrainian amateur astronomer Gennady Borisov on August 30, 2019.
The comet is following a hyperbolic path around the Sun and is currently blazing along at the extraordinary velocity of over 93,200 mph (150,000 kmh).
It will pass through the ecliptic plane — the plane in which Earth and the other planets orbit the Sun — on October 26.
It is expected to make its closest approach to the Sun on December 7, coming within about 182 million miles (293 million km) of our star.
By the middle of 2020, the comet will be on its way back into interstellar space where it will drift for millions of years before maybe one day approaching another star system.
2I/Borisov is only the second such interstellar object known to have passed through our Solar System.
In 2017, the first identified interstellar visitor, an object dubbed ‘Oumuamua, swung within 23.6 million miles (38 million km) of the Sun before racing out of the Solar System.
“Whereas ‘Oumuamua looked like a bare rock, 2I/Borisov is really active, more like a normal comet,” said University of California, Los Angeles astronomer Dr. David Jewitt, leader of the Hubble team who observed the comet.
“It’s a puzzle why these two are so different.”
This illustration shows the path of the interstellar comet 2I/Borisov through our Solar System. Image credit: NASA / ESA / J. Olmsted & F. Summers, STScI.
As the second interstellar object found to enter our Solar System, 2I/Borisov provides various invaluable insights.
For example, it offers clues to the chemical composition, structure, and dust characteristics of a planetary building block presumably forged in an alien star system a long time ago and far away.
“Because another star system could be quite different from our own, the comet could have experienced significant changes during its long interstellar journey,” said Dr. Amaya Moro-Martin, a researcher at the Space Telescope Science Institute.
“Yet its properties are very similar to those of the Solar System’s building blocks, and this is very remarkable.”
Dr. Jewitt, Dr. Moro-Martin and colleagues used Hubble to capture the detailed image of 2I/Borisov.
At the time of observations, the comet was approximately 261 million miles (420 million km) from Earth.
The new Hubble image revealed a central concentration of dust around 2I/Borisov’s nucleus.
“Borisov and ‘Oumuamua are only the beginning of the discoveries of interstellar objects paying a brief visit to our Solar System,” the astronomers said.
“According to a recent study, there are thousands of such interlopers here at any given time, though most are too faint to be detected with current-day telescopes.”
