[meteorite-list] Huge Mini-World Found in Outer Solar System (2004 DW)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:24 2004
Message-ID: <200402192022.MAA01985_at_zagami.jpl.nasa.gov>

http://www.space.com/scienceastronomy/new_object_040219.html

Huge Mini-World Found in Outer Solar System
By Robert Roy Britt
space.com
19 February 2004

A newfound hunk of ice and rock beyond Neptune is larger than
most and might contend for the title of the biggest object in
the solar system besides the Sun, planets and moons.

The object is in a region of frozen, comet-like bodies called
the Kuiper Belt. The discovery was announced today by the Minor
Planet Center in Cambridge, Mass.

Preliminary observations suggest the icy rock, labeled 2004-DW,
is 520-1,170 miles wide (840 to 1,880 kilometers). Physics
dictates that objects this large be generally round, like
mini-worlds.

The largest known Kuiper Belt Object, or KBO, is called Quaoar
(KWAH-o-ar) and was discovered in 2002. Quaoar is roughly
780 miles (1,250 kilometers) wide, about half as big as Pluto.
It orbits the Sun every 288 years, mostly beyond Pluto's orbit.

More observations will be needed to pin down the size of the
newfound KBO. It may turn out to be much smaller than Quaoar,
or it could be bigger.

Researchers estimate the size of these objects by noting
their brightness and making assumptions about how much light
they reflect. Those assumptions assume a certain level of
reflectivity for the surface material.

The discovery was made Tuesday by NASA's Near-Earth Asteroid
Tracking Program at Mt. Palomar in southern California. The
finding was confirmed with observations from the Starkenburg
Observatory in Spain and the Jet Propulsion Laboratory's
Table Mountain Observatory in southern California.

"It wasn't moving much, so I knew it was way out there,"
Table Mountain's Jim Young told SPACE.com. Researchers
measure an object's movement against the fairly stable
background stars to gauge its distance. "I went home and
told my wife, '"That things gotta be big.'"

2004-DW is nearly 47 times as far from the Sun as Earth is.

Scientists expect more large objects to be found in the
Kuiper Belt now that search techniques and technology have
been refined. Some astronomers say it's possible that an
object larger than Pluto might still lurk there unfound.
Received on Thu 19 Feb 2004 03:22:04 PM PST