More Details Emerge About 'Oumuamua, Earth's First-Recorded Interstellar Visitor

 NASA/JPL-Caltech
NASA/JPL-Caltech

In October, scientists using the University of Hawaii's Pan-STARRS 1 telescope sighted something extraordinary: Earth's first confirmed interstellar visitor. Originally called A/2017 U1, the once-mysterious object has a new name—'Oumuamua, according to Scientific American—and researchers continue to learn more about its physical properties. Now, a team from the University of Hawaii's Institute of Astronomy has published a detailed report of what they know so far in Nature.

Fittingly, "'Oumuamua" is Hawaiian for "a messenger from afar arriving first." 'Oumuamua's astronomical designation is 1I/2017 U1. The "I" in 1I/2017 stands for "interstellar." Until now, objects similar to 'Oumuamua were always given "C" and "A" names, which stand for either comet or asteroid. New observations have researchers concluding that 'Oumuamua is unusual for more than its far-flung origins.

It's a cigar-shaped object 10 times longer than it is wide, stretching to a half-mile long. It's also reddish in color, and is similar in some ways to some asteroids in our solar system, the BBC reports. But it's much faster, zipping through our system, and has a totally different orbit from any of those objects.

After initial indecision about whether the object was a comet or an asteroid, the researchers now believe it's an asteroid. Long ago, it might have hurtled from an unknown star system into our own.

'Oumuamua may provide astronomers with new insights into how stars and planets form. The 750,000 asteroids we know of are leftovers from the formation of our solar system, trapped by the Sun's gravity. But what if, billions of years ago, other objects escaped? 'Oumuamua shows us that it's possible; perhaps there are bits and pieces from the early years of our solar system currently visiting other stars.

The researchers say it's surprising that 'Oumuamua is an asteroid instead of a comet, given that in the Oort Cloud—an icy bubble of debris thought to surround our solar system—comets are predicted to outnumber asteroids 200 to 1 and perhaps even as high as 10,000 to 1. If our own solar system is any indication, it's more likely that a comet would take off before an asteroid would.

So where did 'Oumuamua come from? That's still unknown. It's possible it could've been bumped into our realm by a close encounter with a planet—either a smaller, nearby one, or a larger, farther one. If that's the case, the planet remains to be discovered. They believe it's more likely that 'Oumuamua was ejected from a young stellar system, location unknown. And yet, they write, "the possibility that 'Oumuamua has been orbiting the galaxy for billions of years cannot be ruled out."

As for where it's headed, The Atlantic's Marina Koren notes, "It will pass the orbit of Jupiter next May, then Neptune in 2022, and Pluto in 2024. By 2025, it will coast beyond the outer edge of the Kuiper Belt, a field of icy and rocky objects."

Last month, University of Wisconsin–Madison astronomer Ralf Kotulla and scientists from UCLA and the National Optical Astronomy Observatory (NOAO) used the WIYN Telescope on Kitt Peak, Arizona, to take some of the first pictures of 'Oumuamua. You can check them out below.

Images of an interloper from beyond the solar system — an asteroid or a comet — were captured on Oct. 27 by the 3.5-meter WIYN Telescope on Kitt Peak, Ariz.
Images of 'Oumuamua—an asteroid or a comet—were captured on October 27.
WIYN OBSERVATORY/RALF KOTULLA

U1 spotted whizzing through the Solar System in images taken with the WIYN telescope. The faint streaks are background stars. The green circles highlight the position of U1 in each image. In these images U1 is about 10 million times fainter than the faint
The green circles highlight the position of U1 in each image against faint streaks of background stars. In these images, U1 is about 10 million times fainter than the faintest visible stars.
R. Kotulla (University of Wisconsin) & WIYN/NOAO/AURA/NSF

Color image of U1, compiled from observations taken through filters centered at 4750A, 6250A, and 7500A.
Color image of U1.
R. Kotulla (University of Wisconsin) & WIYN/NOAO/AURA/NSF

Editor's note: This story has been updated.

True or False: Was This Object Left on the Moon?

Antibiotic-Resistant Bacteria Discovered on International Space Station Toilet

Antibiotic resistance isn’t just a problem on Earth. It’s happening in space, too. LiveScience reports that NASA scientists have found drug-resistant bacteria in samples from one of the space toilets on the International Space Station.

As part of a study published in the journal BMC Microbiology, scientists from NASA’s Jet Propulsion Laboratory looked at waste samples taken from the ISS in 2015. They isolated five strains of Enterobacter bugandensis bacteria, sequencing their genomes and analyzing their susceptibility to antibiotics. They compared these space strains to strains found on Earth, including some that have been linked to patients in hospital settings.

Normally, because of the lack of interplanetary sewers, astronaut waste is simply flushed into space, where it will incinerate on its way back through Earth’s atmosphere. But for the sake of NASA’s ongoing catalog of microbes found on the ISS, some lucky astronaut got to swab the station’s toilet for samples. They also swabbed the station’s Advanced Resistive Exercise Device, one of the exercise machines astronauts use on the ISS to keep up muscle mass during long periods living in microgravity.

A toilet on the ISS
The space toilet where astronauts collected microbial swabs
Jack Fischer, NASA

Based on their similarity to bacteria strains taken from patients on Earth, the analysis found that the strains isolated from the ISS swabs have a 79 percent probability that they could cause disease in humans. They contained genes associated with antibiotic resistance and toxic compounds.

"Given the multi-drug resistance results for these ISS E. bugandensis genomes and the increased chance of pathogenicity we have identified, these species potentially pose important health considerations for future missions,” the study's lead author, Dr. Nitin Singh, said in a statement. “However, it is important to understand that the strains found on the ISS were not virulent, which means they are not an active threat to human health, but something to be monitored." That means that while astronauts don't need to worry about these bacteria just yet, antibiotic resistance is an issue that NASA will need to prepare for in the future.

[h/t LiveScience]

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