Oct 17 2019
The image of an interstellar visitor, comet 2I/Borisov is the latest offering from NASA's Hubble Space Telescope to astronomers. The speed and trajectory of comet 2I/Borisov show it has come from outside the solar system. The image taken on October 12th, 2019 is the sharpest view of the comet ever to be captured.
Hubble photographed comet 2I/Borisov at a distance of 260 million miles from Earth. This Hubble image, taken on October 12th, 2019, is the sharpest view to date of the comet. Hubble reveals a central concentration of dust around the nucleus (which is too small to be seen by Hubble). The comet is falling toward the Sun and will make its closest approach on December 7th, 2019, when it will be twice as far from the Sun as Earth. The comet is following a hyperbolic path around the Sun and will exit back into interstellar space. (Image credit: NASA, ESA and D. Jewitt (UCLA))
Hubble makes known a core concentration of dust around the nucleus (which is extremely small to be witnessed by Hubble).
Comet 2I/Borisov is only the second such interstellar object known to have traveled via the solar system. In 2017, the first identified interstellar visitor, an object formally referred to as 'Oumuamua, passed within 24 million miles of the Sun before speeding out of the solar system.
Whereas 'Oumuamua appeared to be a rock, Borisov is really active, more like a normal comet. It's a puzzle why these two are so different.
David Jewitt, Hubble Team Lead, University of California, Los Angeles
Jewitt was one of the people who witnessed the comet.
Comet 2I/Borisov offers valuable clues to the structure, chemical composition, and dust characteristics of planetary building blocks seemingly forged in an extraterrestrial star system a long time ago and great distances away.
Though another star system could be quite different from our own, the fact that the comet's properties appear to be very similar to those of the solar system's building blocks is very remarkable.
Amaya Moro-Martin, Space Telescope Science Institute, Baltimore
The comet was photographed by Hubble at a distance of 260 million miles from Earth. The comet is falling past the Sun and will reach closest to the Sun on December 7th, 2019, when it will be twice as remote from the Sun as Earth.
The comet is moving along a hyperbolic path around the Sun, and presently is blazing along at an astonishing speed of 110,000 miles per hour.
It's traveling so fast it almost doesn't care that the Sun is there.
David Jewitt, Hubble Team Lead, University of California, Los Angeles
By mid-2020, the comet will flash past Jupiter's distance of 500 million miles on its way back into interstellar space where it will float for indefinable millions of years before edging close to another star system.
The comet was discovered on August 30th, 2019 by Crimean amateur astronomer Gennady Borisov. After seven days of observations by amateur and professional astronomers across the globe, the International Astronomical Union's Minor Planet Center and the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory in Pasadena, California, computed a trajectory for the comet, which verifies that it originated from interstellar space.
Thus far, all categorized comets have originated from either a ring of icy fragments at the periphery of the solar system, known as the Kuiper belt, or the hypothetical Oort cloud, a shell of comets about a light-year from the Sun, establishing the dynamical edge of the solar system.
Borisov and 'Oumuamua are just the beginning of the discoveries of interstellar objects skirting past the solar system, say scientists. According to one research, there are thousands of such interlopers here at any specific time, though most are extremely faint to be detected with present-day telescopes.
Observations by Hubble and other telescopes have revealed that shells and rings of icy fragments encompass young stars where planet formation is ongoing. A gravitational "pinball game" between planets orbiting other stars or comet-like bodies can plunge them deep into space where they get lost among the stars.
2I/Borisov will be observed by Hubble through January 2020, with more being recommended.
"New comets are always unpredictable," said Max Mutchler, another member of the observing team. "They sometimes brighten suddenly or even begin to fragment as they are exposed to the intense heat of the Sun for the first time. Hubble is poised to monitor whatever happens next with its superior sensitivity and resolution."
The Hubble Space Telescope is a project of global cooperation between NASA and the European Space Agency (ESA). The telescope is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. The Space Telescope Science Institute (STScI) in Baltimore carries out Hubble science operations. STScI is worked for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.
Hubble's New Image of Interstellar Object
(Video credit: NASA's Goddard Space Flight Center)