UCLA astronomer gets best look at first comet from outside our solar system

The comet 2I/Borisov, as seen on Oct. 12 with NASA’s Hubble Space Telescope. Scientists believe the comet is from another solar system. Photo credit: NASA, ESA and David Jewitt/UCLA

David Jewitt, a UCLA professor of planetary science and astronomy, has captured the best and sharpest look at a comet from outside of our solar system that recently barged into our own. It is the first interstellar comet astronomers have observed.

Comet 2I/Borisov (the “I” stands for interstellar) is following a path around the sun at a blazing speed of approximately 110,000 miles per hour, or about as fast as Earth travels around the sun. Jewitt studied it on Oct. 12 using NASA’s Hubble Space Telescope, which captured images of the object when it was about 260 million miles away. He observed a central concentration of dust around the comet’s solid icy nucleus — the nucleus itself is too small to be seen by Hubble — with a 100,000-mile-long dust tail streaming behind.

Jewitt said it’s very different from another interstellar object, dubbed ‘Oumuamua, that a University of Hawaii astronomer observed in 2017 before it raced out of our solar system.

“‘Oumuamua looked like a bare rock, but Borisov is really active — more like a normal comet,” said Jewitt, who leads the Hubble team. “It’s a puzzle why these two are so different. There is so much dust on this thing we’ll have to work hard to dig out the nucleus.”

That work will involve sophisticated image processing to separate the light scattered from the nucleus from light scattered by dust.

► View a 2-second time lapse video of the comet

2I/Borisov and ‘Oumuamua are the first two objects that have traveled from outside of our solar system into ours that astronomers have observed, but that’s because scientists’ knowledge and equipment are much better now than they ever have been, and because they know how to find them. One study indicates there are thousands of such comets in our solar system at any given time, although most are too faint to be detected with current telescopes.

Until 2I/Borisov, every comet that astronomers have observed originated from one of two places. One is the Kuiper belt, a region at the periphery of our solar system, beyond Neptune, that Jewitt co-discovered in 1992. The other is the Oort Cloud, a very large spherical region approximately a light-year from the sun, which astronomers think contains hundreds of billions of comets.

2I/Borisov was initially detected on Aug. 30 by Gennady Borisov at the Crimean Astrophysical Observatory, when it was 300 million miles from the sun. Jewitt said its unusually fast speed — too fast for the sun’s gravity to keep it bound in an orbit — indicates that it came from another solar system and that it is on a long path en route back to its home solar system.

Because the comet was presumably forged in a distant solar system, the comet provides valuable clues about the chemical composition and structure of the system where it originated.

2I/Borisov will be visible in the southern sky for several months. It will make its closest approach to the sun on Dec. 7, when it will be twice as far from the sun as Earth is. By the middle of 2020, it will pass Jupiter on its way back into interstellar space, where it will drift for billions of years, Jewitt said.

Comets are icy bodies thought to be fragments left behind when planets form in the outer parts of planetary systems.

20 new moons for Saturn

In separate research that has not yet been published, Jewitt is part of a team that has identified 20 previously undiscovered moons of Saturn, for a new total of 82 moons. The revised figure gives Saturn more moons than Jupiter, which has 79.

The new objects are all small, typically a few miles in diameter, and were discovered using the Subaru telescope on Maunakea in Hawaii. They can be seen only using the world’s largest telescopes, Jewitt said.

The moons might have formed in the Kuiper belt, said Jewitt, a member of the National Academy of Sciences and a fellow of the American Association for the Advancement of Science and of the American Academy of Arts and Sciences.

The research team was headed by Scott Sheppard, a staff scientist at the Carnegie Institution for Science, and includes Jan Kleyna, a postdoctoral scholar at the University of Hawaii.

This article originally appeared in the UCLA Newsroom.

Minds Matter: Raising the Curtain on Depression and Anxiety

Photo of Cleveland Cavaliers basketball player Kevin Love and UCLA College’s Clinical Psychology expert Michelle Craske.

Cleveland Cavaliers basketball player Kevin Love and UCLA College’s Clinical Psychology expert Michelle Craske.

UCLA students, community members and supporters joined Cleveland Cavaliers basketball player Kevin Love and UCLA College’s Clinical Psychology expert Michelle Craske for a standing-room only hybrid class and public lecture on Monday, August 19, for “Minds Matter: Raising the Curtain on Depression and Anxiety,” a free hour-long discussion on the causes of depression and anxiety, public stigma, and potential advances for the future. The series was the first in an ongoing exploration of brain health that will continue with additional events focusing on bullying, aging well, and other topics.

Love, an NBA Champion and five-time NBA All-Star for the Cleveland Cavaliers, has publicly discussed his struggle with panic attacks and anxiety and his decision to seek therapy, and has become a leading voice in mental health advocacy and founded the Kevin Love Fund in 2018 with the mission of inspiring people to live their healthiest lives while providing the tools to achieve physical and emotional well-being.

“Mental health isn’t just an athlete thing, it’s an issue that affects everyone in some way. The more we can normalize the conversation around mental health, the more we can do to help those that are struggling,” said Love. “My goal in sharing my personal experience is to connect with others who are going through something and keep this dialogue top of mind.”

Michelle G. Craske is a UCLA Professor of Psychology, Psychiatry and Biobehavioral Sciences, Director of the Anxiety and Depression Research Center, and Associate Director of the Staglin Family Music Center for Behavioral and Brain Health. Craske has published extensively in the area of fear, anxiety and depression.

“We need to work together to bring anxiety and depression out of the dark. People who suffer will only seek help when they can do so without fear of shame. Event series such as ‘Minds Matter’ aim to shed a light on these critical issues, and to help make a positive breakthrough,” said Craske.

Craske also is Director of the Innovative Treatment Network within the UCLA Depression Grand Challenge, a campus-wide effort to cut the global burden of depression in half. The innovative treatment component, which Craske leads, seeks to develop novel and more effective treatments for depression and anxiety and increase the scalability and accessibility of existing evidence-based treatments.

The “Minds Matter” series leverages the strengths of UCLA College’s Psychology faculty as well as high-profile guests who provide specialized insight about the discussion topic. Upcoming sessions will include discussions on addiction, adolescent brain development and behavior, bullying, healthy aging, and thriving under stress. The “Minds Matter” series is made possible through the longstanding UCLA College and Geffen Playhouse partnership and the generous support of donors.

Check back for information on future “Minds Matter” events at  https://www.college.ucla.edu/minds-matter/.