LOS ANGELES (AP)
— Peering into the far reaches of the solar system, astronomers have spied
a pink frozen world 7½ billion miles from the sun.
It's the second
such object to be discovered in a region of space beyond Pluto long
considered a celestial wasteland. Until now, the lone known resident in
this part of the solar system was an oddball dwarf planet spotted in 2003
named Sedna after the mythological Inuit goddess who created the sea
creatures of the Arctic.
discovery shows "Sedna is not a freak. We can have confidence that there
is a new population to explore," Yale University senior research scientist
David Rabinowitz said in an email. He was one of Sedna's discoverers, but
had no role in the new find detailed in Thursday's issue of the journal
astronomers hunted in vain for other Sednas in the little-studied fringes
of the solar system.
The new object,
2012 VP113, was tracked using a new camera on a ground telescope in Chile
by Scott Sheppard of the Carnegie Institution for Science in Washington,
D.C., and Chad Trujillo of the Gemini Observatory in Hawaii. Trujillo was
part of the team that found Sedna.
Like Sedna, VP is
also a dwarf planet. It's jokingly nicknamed "Biden" after Vice President
Joe Biden because of the object's initials. It measures about 280 miles
across, or half the diameter of Sedna. It's bone-chilling cold with a
temperature of around minus 430 degrees Fahrenheit.
Unlike red and
shiny Sedna, the newfound object is more pink and much fainter, which made
it hard to detect.
Earth is about 7,900 miles across and located 93 million miles from the
Sedna and VP
reside in what's known as the inner Oort cloud in the outer edge of the
solar system where some comets such as the sun-diving Comet ISON are
thought to originate. ISON broke apart last year after brushing too close
to the sun.
"Finding Sedna so
far away seemed odd and potentially a fluke. But this one is beginning to
make it look like that might be a typical place for objects to be. Not at
all what I would have guessed," Mike Brown, an astronomer at the
California Institute of Technology, said in an email.
self-proclaimed "Pluto killer," led the Sedna team, but was not part of
the new discovery.
Far from being
deserted, Sheppard and Trujillo estimate there are probably thousands of
similar objects in the inner Oort cloud.
are not unique. There's a huge number out there," Sheppard said.
Not all of them
will be visible to telescopes because they're so far away and it takes a
long time for them to swing by the sun. Sedna and VP were spotted at their
closest approach to the sun, which allowed light from the sun to hit the
objects and bounce back to observatories on Earth.
VP is currently
the third farthest object in the solar system after dwarf planet Eris and
Sedna, but it has an eccentric, elongated orbit that can take it out to 42
billion miles from the sun. Sedna can loop out as far as 84 billion miles
from the sun at its farthest point.
Now that Sedna
has company — and likely lots of them — scientists are searching for more
objects in an effort to learn how they and the solar system formed and
In a separate
discovery published in Nature, a team led by Felipe Braga-Ribas of the
National Observatory in Brazil found a pair of rings around an
asteroid-like interloper in the outer system named Chariklo.
While not as
dazzling as Saturn's rings, it's the first time rings have been discovered
outside of the four gas giants — Jupiter, Saturn, Uranus and Neptune. How
little Chariklo got its rings remains a mystery, but scientists think they
may have formed from debris from a violent collision.