Interesting. A personal observation not related to the science of this article:
the usage of the term "size does matter" is getting a bit old, isn't it? I hear
it in all kinds of movie/TV stuff, home improvement shows, now even
astronomical press coverage? Ugh.
----- Original Message -----
From: "Mr. Worf" <hellomahog...@gmail.com>
To: scifinoir2@yahoogroups.com
Sent: Tuesday, January 26, 2010 12:54:09 AM GMT -05:00 US/Canada Eastern
Subject: [scifinoir2] Pluto's Little Sister Found?
Pluto's Little Sister Found?
When it comes to objects in the Kuiper Belt, the vast, icy ring that encircles
our solar system, size matters.
By Irene Klotz | Mon Jan 25, 2010 01:49 PM ET
Pluto's Little Sister Found?
The smallest object ever found in the Kuiper Belt, a vast, icy ring that
encircles our solar system, helps to explain how these debris disks are formed.
NASA, ESA, and G. Bacon (STScI)
THE GIST:
• An icy body one-third of a mile wide is the smallest known object ever
found in the Kuiper Belt.
• The Kuiper Belt is a vast, icy ring just beyond Neptune that encircles
the solar system.
• The discovery links solar system formation to planet-forming debris disks
around other stars.
The frozen worlds orbiting beyond Neptune include not only dwarf planets like
Pluto and Ceres, but also a tiny, icy toehold just one-third of a mile wide.
The discovery, made by a team of astronomers scouring Hubble Space Telescope
observations, sets a new record for the smallest Kuiper Belt object found.
Previously, the smallest known Pluto sibling was a 30-mile-wide Kuiper Belt
object.
The Kuiper Belt region, located about 4.6 billion miles away, is filled with
objects believed to be left over from the solar system's formation. It is
similar to the asteroid belt, located between Mars and Jupiter, but much
bigger. Unlike the asteroids that contain rock and metals, Kuiper Belt objects
have icy bodies of methane, ammonia, water and other volatiles.
The Kuiper Belt is particularly interesting to scientists looking for planetary
systems beyond our solar system . Planets are believed to form from collapsing
disks of gas and dust orbiting stars.
"The dusty particles begin to stick together and eventually build up larger
objects. Not all make it into planets. It's the leftover ones are what we're
seeing when we look at Kuiper Belt objects and asteroids," University of
Arizona astronomer John Stansberry told Discovery News.
The finding of a very small Kuiper Belt object links our solar system's debris
disk to those observed around other stars, added University of Toronto's Hilke
Schlichting, who led the team that made the discovery.
"We can observe micron-sized particles (in extrasolar debris disks), which are
thought to be induced by collisions, from grinding down larger objects,"
Schlichting told Discovery News. "By finding this evidence for collision
grinding in the Kuiper Belt, it seems to be the missing link between our Kuiper
Belt and extrasolar debris disks."
When it comes to Kuiper Belt objects, size matters. Scientists can use this
information to determine an object's density and what it is made from. In
larger bodies, gravity plays the dominant role in shaping objects. In smaller
ones, it is the strength of its materials that matters.
astrophysicist asteroid
WATCH VIDEO: Astrophysicist Andy Puckett explores the universe, especially
undiscovered asteroids that could one day smack into our planet.
Related Links:
• Taking the Kuiper Belt Census
• Wide Angle: Asteroids
• HowStuffWorks.com: Kuiper Belt
• Pluto, Sponsored By McDonalds
"The discovery of just one small object is probably not going to lead to great
advances. But if we started to discover statistically significant numbers of
them, then we can compare the number of large and small bodies, and you can
start to get a handle on the material strength of the objects. It also might
tell you about the violence of the collisions," said Stansberry.
"Potentially, it might be a new field if we can make more discoveries like
this," he added.
Schlichting and colleagues combed through 4.5 years of Hubble data to find the
tiny Kuiper Belt Object, discovered as it passed in front of a background star,
momentarily dimming its light.
"These tiny objects are much rarer than you would expect," Schlichting told
Discovery News.
Based on the number of known objects in the Kuiper Belt, scientists would have
expected to find between 30 and 100 tiny bodies in their analysis of 50,000
guide stars observed by Hubble.
So far, the team has only looked at 30 percent of the available Hubble data.
"We only found one," Schlichting said. "It shows that there's kind of a break
in the size of objects in the Kuiper Belt from large objects, meaning bigger
than 50 kilometers (31 miles), and smaller ones."
The dearth of small bodies may be evidence that objects in the Kuiper Belt are
crashing and grinding down, she added.
The research was published last month in Nature .
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