Nav: Home

First known interstellar visitor is an 'oddball'

November 20, 2017

In October astronomers were surprised by a visitor that came racing into our Solar System from interstellar space. Now, researchers using the Gemini Observatory have determined that the first known object to graze our Solar System from beyond is similar to, but definitely not, your average asteroid or comet. "This thing is an oddball," said Karen Meech of the University of Hawaii's Institute for Astronomy who leads an international team studying this interstellar interloper.

Originally denoted A2017 U1, the body now goes by the Hawaiian name 'Oumuamua, in part because of its discovery by Meech's team using the Pan-STARRS1 survey telescope on Haleakala in Hawai'i. When discovered in mid-October 'Oumuamua was only about 85 times the Earth-Moon distance away and its discovery was announced in early November.

Since its discovery 'Oumuamua has faded from view. The object's rapidly increasing distance from the Earth and Sun now makes it too faint to be studied by even the largest telescopes.

"Needless to say, we dropped everything so we could quickly point the Gemini telescopes at this object immediately after its discovery," said Gemini Director Laura Ferrarese who coordinated the Gemini South observations for Meech's group.

"What we found was a rapidly rotating object, at least the size of a football field, that changed in brightness quite dramatically," according to Meech. "This change in brightness hints that 'Oumuamua could be more than 10 times longer than it is wide - something which has never been seen in our own Solar System," according to Meech.

'Oumuamua shares similarities with small objects in the outer Solar System, especially the distant worlds of the Kuiper Belt - a region of rocky, frigid worlds far beyond Neptune. "While study of 'Oumuamua's colors shows that this body shares characteristics with both Kuiper Belt objects and organic-rich comets and trojan asteroids," says Meech, "its orbital path says it comes from far beyond."

The research led by Meech is published in the November 20th online issue of the journal Nature.

'Oumuamua was visible from Chile and Hawai'i so both Gemini North and South telescopes were on high alert and ready to track the visitor from outer space. "We observed from both sites for three nights, before it sped away and faded from view," said Ferrarese. Two additional teams obtained data from Gemini North and their results are currently pending publication.

According to our current understanding of planetary system formation, our Solar System ejected comets and asteroids due to interactions with the larger outer planets. It is presumed that other planetary systems do the same and that these visitors might be more common than previously thought. "We estimate that there is always one of these objects of similar size as 'Oumuamua between the Earth and the Sun at any given time, so up to about 10 per year," says Robert Jedicke also on Meech's team.

"These observations allow us to reach into another planetary system to learn about one of its rocky bodies, and compare this object with the asteroids we know throughout our own Solar System", says Faith Vilas, the solar and planetary research program director at the National Science Foundation who helped support this research.

Surveys like Pan-STARRS and the future Large Synoptic Survey Telescope (LSST, currently under construction near the Gemini South telescope in Chile) will undoubtedly increase the detections of these interstellar wanderers.

"The discoveries of rare surprises like 'Oumuamua from outside our Solar System will be greatly accelerated by the power and grasp of the LSST," said Richard Green of the US National Science Foundation (NSF). "LSST is going to produce a torrent of data and revolutionize this sort of time domain astronomy when it begins operations early in the next decade," adds Green. LSST is funded by a partnership with the NSF, the Department of Energy, and the LSST Corporation.

'Oumuamua loosely means "a messenger that reaches out from the distant past," fitting the nature of the object's interstellar origin. In Hawaiian 'ou means "to reach out for," while mua means "first" and is repeated for emphasis.

Science Contacts:

Karen Meech
University of Hawaii Institute for Astronomy
E-mail: meech@ifa.hawaii.edu
Cell: 720-231-7048 CST

Richard Wainscoat
University of Hawaii Institute for Astronomy
E-mail: rjw@ifa.hawaii.edu
Cell: 808-741-4805 HST

Media Contacts:

Peter Michaud
Gemini Observatory
E-mail: pmichaud@gemini.edu
Desk: 808-974-2510
Cell: 808-936-6643

Roy Gal
University of Hawaii Institute for Astronomy
E-mail: roygal@hawaii.edu
Cell: 301-728-8637

ABOUT THE GEMINI OBSERVATORY

The Gemini Observatory is a facility of the National Science Foundation (NSF-United States), the National Research Council (NRC-Canada), the Ministério da Ciência, Tecnologia e Inovação (MCTI - Brazil), the Ministerio de Ciencia, Technología e Innovación Productiva (MCTIP - Argentina), and the Comisión Nacional de Investigación Científica y Technológica (CONICYT - Chile), operated under cooperative agreement by the Association of Universities for Research in Astronomy, Inc. (AURA).

The international Gemini collaboration provides access to two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai'i (Gemini North) and the Gemini South telescope is on Cerro Pachón in central Chile; together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space. The Observatory provides the astronomical communities in each of the five participating countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country's contribution. In addition to financial support, each country also contributes significant scientific and technical resources.
-end-


Association of Universities for Research in Astronomy (AURA)

Related Solar System Articles:

Second alignment plane of solar system discovered
A study of comet motions indicates that the Solar System has a second alignment plane.
Pressure runs high at edge of solar system
Out at the boundary of our solar system, pressure runs high.
What a dying star's ashes tell us about the birth of our solar system
A UA-led team of researchers discovered a dust grain forged in a stellar explosion before our solar system was born.
What scientists found after sifting through dust in the solar system
Two recent studies report discoveries of dust rings in the inner solar system: a dust ring at Mercury's orbit, and a group of never-before-detected asteroids co-orbiting with Venus, supplying the dust in Venus' orbit.
Discovered: The most-distant solar system object ever observed
A team of astronomers has discovered the most-distant body ever observed in our solar system.
Discovery of the first body in the Solar System with an extrasolar origin
Asteroid 2015 BZ509 is the very first object in the Solar System shown to have an extrasolar origin.
First interstellar immigrant discovered in the solar system
A new study has discovered the first known permanent immigrant to our solar system.
A star disturbed the comets of the solar system in prehistory
About 70,000 years ago, when the human species was already on Earth, a small reddish star approached our solar system and gravitationally disturbed comets and asteroids.
Scientists detect comets outside our solar system
Scientists from MIT and other institutions, working closely with amateur astronomers, have spotted the dusty tails of six exocomets -- comets outside our solar system -- orbiting a faint star 800 light years from Earth.
Does the organic material of comets predate our solar system?
The Rosetta space probe discovered a large amount of organic material in the nucleus of comet 'Chury.' In an article published by MNRAS on Aug.
More Solar System News and Solar System Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.