Newfound comet likely an ‘interstellar visitor,’ scientists say

Comet C/2019 Q4 is imaged by the Canada-France-Hawaii Telescope on Hawaii's Big Island September 10, 2019. NASA/JPL/Canada-France-Hawaii Telescope/Handout via REUTERS

By Joey Roulette

(Reuters) – A newly discovered comet hurtling toward the orbit of Mars has scientists scurrying to confirm whether it came from outside the solar system, a likely prospect that would make it the second such interstellar object observed in our planetary neighborhood.

The trajectory of the comet, first detected by Crimean astronomer Gennady Borisov, follows a highly curved path barreling in the sun’s direction at unusually high speeds, evidence that it originated beyond the solar system.

“On our team we’ve been scrambling here at the University of Hawaii to get observations to make position measurements,” said Karen Meech, an astronomer at the university whose team concluded that the object’s size and tail of gas classify it as a comet.

“Every time a new comet is discovered, everybody starts to try and get data so that you can get the orbit,” Meech told Reuters, adding that her researchers “all are 100 percent convinced that this really, truly is interstellar.”

The comet, an apparent amalgam of ice and dust, is expected to make its closest approach to the sun on Dec. 8, putting it 190 million miles (300 million km) from Earth, on a route believed unique to such objects of interstellar origin.

Once confirmed interstellar, the comet – dubbed C/2019 Q4 by astronomers – would become only the second such body ever observed by scientists.

The first was a cigar-shaped comet dubbed ‘Oumuamua – a name of Hawaiian origin meaning a messenger from afar arriving first – that sailed into our planetary neighborhood in 2017, prompting initial speculation that it may have been an alien spacecraft. Astronomers soon reached a consensus that it was not.

Unlike ‘Oumuamua, which visited the solar system for only a week, the newfound comet will linger near Mars’ orbit for almost a year, giving scientists ample time to characterize its chemical signatures and seek further clues about its origin.

“The high velocity indicates not only that the object likely originated from outside our solar system, but also that it will leave and head back to interstellar space,” said Davide Farnocchia, an astronomer at NASA’s Jet Propulsion Laboratory in California.

(Reporting by Joey Roulette in Washington; Editing by Steve Gorman and Leslie Adler)

Cigar-shaped interstellar visitor ‘Oumuamua classified as comet

This artist’s impression shows the first interstellar asteroid, `Oumuamua as it passes through the solar system after its discovery in October 2017. European Southern Obervatory/M. Kornmesser/Handout via REUTERS

By Will Dunham

WASHINGTON (Reuters) – The reddish cigar-shaped object called ‘Oumuamua spotted last year tumbling through space is a comet, scientists said on Wednesday, solving the mystery over how to classify the first interstellar object found passing through our solar system.

Astronomers said they closely examined the trajectory of ‘Oumuamua, which measures about a half-mile (800 meters) long, as it speeds through our cosmic neighborhood after being evicted somehow from a distant star system.

They found that it is deviating slightly from a path that would be explained purely by the Sun’s gravitational pull because of what apparently is a very small emission of gas from its surface, indicative of a comet.

‘Oumuamua (pronounced oh-MOO-uh-MOO-uh) initially was pegged as a comet, but it lacks the tail of gas and dust characteristic of many comets, and some scientists argued that it was perhaps a dry asteroid.

“It does not display any tail in any observation we obtained,” said astronomer Marco Micheli of the European Space Agency’s SSA-NEO Coordination Centre in Italy, who led the study, published in the journal Nature.

“However, our analysis shows that the amount of emitted gas that is needed to generate this extra force we see would have been so small as to be invisible in our observations,” he said in an email.

This “extra force” acting on the object’s trajectory amounts to only about 0.1 percent of the Sun’s gravitational attraction.

‘Oumuamua was first detected last October by the University of Hawaii’s Pan-STARRS1 telescope. Its name refers in the native Hawaiian language to a messenger arriving from a great distance.

It previously slingshot past the Sun traveling at roughly 196,000 miles per hour (315,000 km per hour) and is heading out of the solar system in the direction of the constellation Pegasus. ‘Oumuamua as of last month was roughly the same distance from the Sun as Jupiter.

Astronomers suspect that more visitors from other star systems will be discovered passing through our solar system.

“The discovery of ‘Oumuamua is an absolute first in the field, and it provided our first opportunity to study an object coming from another star and planetary system,” Micheli said. “The existence of these objects was expected, but seeing one for the first time, and being able to study it in detail, is a unique chance to know more on these distant systems, and how they formed.”

(Reporting by Will Dunham; Editing by Steve Orlofsky)