Astronomers Spot Most Distant Object So Far In The Solar System

Nov 11, 2015
Originally published on November 16, 2015 6:11 pm

Astronomers have spotted what they believe to be the most distant object ever seen in our solar system.

The dwarf planet, known for now simply as V774104, is more than 100 times farther from the sun than we are. Astronomers aren't sure what it's doing out there, but they're hoping follow-up studies of its orbit will teach them more.

V774104 was first noticed in mid-October. Astronomer Scott Sheppard and his colleagues were using the Subaru telescope in Hawaii to hunt for faint, distant objects orbiting the sun. Basically they were just pointing the building-sized telescope at random patches of sky to try to catch anything moving out there.

"Generally we're just randomly shooting for the most part, because we don't know where these objects might be," he says.

They recorded loads of pictures. A computer sifted through the images, looking for anything that seemed to be moving. Then the program flagged the interesting photos for follow-up. Sheppard put the data on his laptop and headed home to Washington.

That's when he made the discovery.

"I remember I was flying back on the plane, looking through the data, and I remember when this popped up on the screen, my eyes opened up," he says.

It was just a little pinprick of light, but it was moving slowly across the sky. Doing the math, Sheppard realized this could very well be the most distant thing ever seen in our solar system.

V774104 is "three times farther than Pluto is from the sun," he says.

Sheppard announced the discovery Monday at the American Astronomical Society's Division of Planetary Sciences meeting in National Harbor, Maryland.

The new world is tiny, much smaller than our own moon. Sheppard thinks it's probably made of ice. But the real question is how did it get all the way out there?

One theory is a rogue planet was thrown out of the early solar system and dragged this poor little guy along.

"If a large planet formed in our solar system and got tossed out, it could pull objects out with it as it was leaving our solar system and kind of drop objects along the way like Hansel and Gretel," he says.

It's also possible this world came from another star system and ended up around the sun.

Sheppard is trying to find out more by making further observations of the new dwarf planet's orbit. Those observations might also show that it's not quite as far away as initially thought. But even if it doesn't break a record, Sheppard isn't worried.

"This object is basically going to be interesting no matter what we find its orbit to be," he says.

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STEVE INSKEEP, HOST:

Astronomers spotted what they think is the most distant object ever seen in the solar system - a dwarf planet 100 times farther from the sun than we are. NPR's Geoff Brumfiel has more on this tiny world.

GEOFF BRUMFIEL, BYLINE: Last month, astronomer Scott Sheppard was in Hawaii, but he wasn't on the beach tanning. He was on top of a 13,000-foot volcano called Mauna Kea. He was using a telescope there, and it was the middle of the night.

SCOTT SHEPPARD: We stay up all night with the telescopes, getting the data.

BRUMFIEL: Shepperd is an astronomer at the Carnegie Institution for Science. He and his colleagues were looking for faint, distant objects orbiting the sun. Basically, they were just pointing the building-sized telescope at patches of sky to try and catch anything moving out there.

SHEPPARD: Generally, we're just randomly shooting for the most part because we don't know where these objects would be.

BRUMFIEL: So this was literally, like, a shot in the dark.

SHEPPARD: A shot in the dark, needle in the haystack - whatever you want to call it.

BRUMFIEL: They recorded loads of pictures. A computer sifted through the images, looking for anything moving from one image to the next. It flagged the interesting ones for follow-up. Shepperd put the data on his laptop and headed home to Washington, D.C., and that's when he made the discovery.

SHEPPARD: Yeah, I remember I was actually flying on the plane back, looking through the data. And I remember when this popped up on my screen, I immediately - my eyes opened up.

BRUMFIEL: It was just a little pinprick of light, but it was moving slowly across the sky. Doing the math, Shepperd realized this could very well be the most distant thing ever seen in our solar system.

SHEPPARD: Three times further than Pluto is from the sun.

BRUMFIEL: Shepperd announced the discovery Monday at an astronomy meeting in Maryland. The new world is tiny - much smaller than our own moon. Shepperd thinks it's probably made of ice. The real mystery - how did it get all the way out there? One theory is a rogue planet was thrown out of the early solar system and dragged this poor little guy along.

SHEPPARD: If large planet formed in our solar system got tossed out, it could pull objects out with it as it was leaving our solar system and kind of drop objects along the way like Hansel and Gretel.

BRUMFIEL: Or maybe this world came from another star system and ended up around the sun. Shepperd's trying to find out more. Now, there is also a chance that this object isn't as far as way as he first thought, but if the record stands, will he get a prize?

SHEPPARD: The prize is I get to keep my job, I guess. This object is basically going to be interesting no matter what we find its orbit to be, and that's the joy of science. It's just looking at the unknown and figuring out what the unknown is.

BRUMFIEL: Shepperd and his team will get to name the frosty world. He's leaning towards deities from Hawaiian mythology - may be a god of ice or snow. Geoff Brumfiel, NPR News. Transcript provided by NPR, Copyright NPR.