It took more than 9 years for NASA’s New Horizons spacecraft to travel more than 3 billion miles to Pluto. That’s nothing compared to a new dwarf planet just discovered by astronomers. V774104 is the most distant object in the solar system and sits three times farther away than Pluto.
Scientists don’t know much about V774104, but they do know it’s between about 300 and 600 miles across. Compare that to Pluto, which is 1,474 miles across, V774104 is tiny. It’s also smaller than another distant planet, Sedna, which has a diameter of about 620 miles.
What could make V774104 so special is its orbit. It’ll take another year or so for scientists to nail it down, but this dwarf planet may join an exclusive club of other objects including Sedna.
Scott Sheppard, an astronomer at the Carnegie Institution for Science, talked to Science about what’s so intriguing with these dwarf planets. “We can’t explain these objects’ orbits from what we know about the solar system,” said Sheppard.
Between the Sun and about 50 astronomical units (AU) away (one AU is the distance between the Sun and Earth), scientists can explain every object’s orbit. This includes all the planets and dwarf planets residing in the Kuiper Belt. But past 50 AU is where scientists have trouble explaining what’s going on. Sedna and 2012 VP113 never come within 50 AU of the sun during their orbits. And they can go as far out as 1,000 AU. Here’s Sedna’s orbit. The purple circle is Pluto’s orbit.
You’re probably asking yourself how a large planet at the edge of our solar system hasn’t been discovered yet? Sedna and 2012 VP113 were only discovered when their orbits reached the closest point to the Sun. When they swing to the most distant points of their orbits, they are too faint to discover.
Another theory suggests a giant planet was tossed out during the formation of our solar system and affected the orbits of these dwarf planets on the way out.
Now, V774101 may have a normal orbit. If its orbit brings it to within 50 AU, it will be classified as a scattered Kuiper Belt Object. If its orbit keeps it past 50 AU, it will be classified as an inner Oort cloud object.
To find V774101, Sheppard and his colleagues used Japan’s 8-meter Subaru Telescope on top of Mauna Kea in Hawaii.