Featured Research

from universities, journals, and other organizations

Astronomers Discover Apparent "Outer Edge" To The Solar System

Date:
October 30, 2000
Source:
University Of Arizona
Summary:
Our solar system may have an outer "edge" just outside the orbit of Pluto, astronomers announced recently. Their results suggest that early in the history of the solar system, some event stripped away most of the planet-building material beyond 50 times Earth's distrance from the sun.

Our solar system may have an outer "edge" just outside the orbit of Pluto, astronomers announced recently. Their results suggest that early in the history of the solar system, some event stripped away most of the planet-building material beyond 50 times Earth's distrance from the sun.

Related Articles


Lynne Allen and Gary Bernstein, of the University of Michigan, and Renu Malhotra of the University of Arizona Lunar and Planetary Laboratory presented the evidence October 24, 2000 at the Division of Planetary Sciences meeting in Pasadena.

It has long been thought that some comets must originate from a collection of small icy bodies orbiting beyond Neptune. These so-called "Kuiper Belt Objects" would be left over from the formation of the large planets 5 billion years ago. The Kuiper Belt Objects were purely hypothetical until 1992, when David Jewitt and Jane Luu of the University of Hawaii discovered the first one. Since that time, over 300 Kuiper Belt Objects have been discovered -but none of them are more than about 55 times as far from the sun as Earth, or 55 AU.

Astronomers talk about solar system distances in terms of "astronomical units." An astronomical unit, or one AU, is the distance from Earth to the sun. By comparison, Neptune is 30 AU from the sun, and Pluto ranges from between 30 to 50 AU.

Does the solar system really end beyond Pluto's orbit? Or are the more distant objects just too faint to have been found so far? To address this question, Allen, Bernstein, and Malhotra searched 6 patches of sky, each about the size of the full moon, using a state-of-the-art electronic camera at the Cerro Tololo Inter-American Observatory in the Chilean Andes.

Astronomers have discovered more than 300 Kuiper Belt Objects, but none of them are more than 55 times as far from the sun as Earth. Does the solar system really end beyond Pluto's orbit?

These observations, in 1998 and 1999, were sensitive enough to see a 160-kilometer (100-mile) Kuiper Belt Object to at least 65 AU. They discovered 24 new Kuiper Belt Objects, 9 of which are 160 kilometers or bigger, but again the most distant is near the outer limit of Pluto's orbit. This is the strongest evidence yet that more distant objects are missing.

Some of the known Kuiper Belt Objects as well as many comets are on trajectories that will carry them well beyond the orbit of Pluto. But these are all believed to have formed inside Pluto's orbit and then been pushed outward by an encounter with Neptune or another planet. There are still no known objects which appear to have been created outside Pluto's orbit.

So astronomers are left to wonder what explains this apparent edge: was the primordial solar system originally "small"? Or were there once more distant objects that were pulled away by the gravity of a passing star? Astronomers at telescopes around the world are currently conducting further surveys in an effort to learn more about the history of our solar system.

This Kuiper Belt survey was funded by grants from NASA and the National Science Foundation.

Images and text available at http://www.astro.lsa.umich/users/garyb/WWWKBO.


Story Source:

The above story is based on materials provided by University Of Arizona. Note: Materials may be edited for content and length.


Cite This Page:

University Of Arizona. "Astronomers Discover Apparent "Outer Edge" To The Solar System." ScienceDaily. ScienceDaily, 30 October 2000. <www.sciencedaily.com/releases/2000/10/001030082725.htm>.
University Of Arizona. (2000, October 30). Astronomers Discover Apparent "Outer Edge" To The Solar System. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2000/10/001030082725.htm
University Of Arizona. "Astronomers Discover Apparent "Outer Edge" To The Solar System." ScienceDaily. www.sciencedaily.com/releases/2000/10/001030082725.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Space & Time News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What's Up March 2015

What's Up March 2015

NASA (Mar. 4, 2015) — A total solar eclipse in the North Atlantic and tips to prepare for the next U.S. eclipse. Video provided by NASA
Powered by NewsLook.com
Raw: SpaceX Launches Rocket, Satellites on Board

Raw: SpaceX Launches Rocket, Satellites on Board

AP (Mar. 2, 2015) — SpaceX launched it&apos;s 16th Falcon 9 rocket from Cape Canaveral, Florida on Sunday night. The rocket was carrying two commercial communications satellites. (March 2) Video provided by AP
Powered by NewsLook.com
NASA EDGE: SMAP Launch

NASA EDGE: SMAP Launch

NASA (Mar. 2, 2015) — Join NASA EDGE as they cover the launch of the Soil Moisture Active Passive (SMAP) spacecraft live from Vandenberg Air Force Base.  Special guests include NASA Administrator Charlie Bolden, SMAP Project System Engineer Shawn Goodman and Lt Col Brande Walton and Joseph Sims from the Air Force.  No word on the Co-Host&apos;s whereabouts. Video provided by NASA
Powered by NewsLook.com
Astronauts Leave Space Station for Third Spacewalk

Astronauts Leave Space Station for Third Spacewalk

Reuters - News Video Online (Mar. 1, 2015) — NASA Commander Barry Wilmore and Flight Engineer Terry Virts perform their third spacewalk in eight days outside the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins