Featured Research

from universities, journals, and other organizations

Icy wreckage discovered in nearby planetary system

Date:
March 6, 2014
Source:
National Radio Astronomy Observatory
Summary:
Astronomers have discovered the splattered remains of comets colliding together around a nearby star. The researchers believe they are witnessing the total destruction of one of these icy bodies once every five minutes.

This artist's concept illustrates the preferred model for explaining ALMA observations of Beta Pictoris. At the outer fringes of the system, the gravitational influence of a hypothetical giant planet (bottom left) captures comets into a dense, massive swarm (right) where frequent collisions occur.
Credit: NASA's Goddard Space Flight Center/F. Reddy

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have discovered the splattered remains of comets colliding together around a nearby star; the researchers believe they are witnessing the total destruction of one of these icy bodies once every five minutes.

The "smoking gun" implicating this frosty demolition is the detection of a surprisingly compact region of carbon monoxide (CO) gas swirling around the young, nearby star Beta Pictoris.

"Molecules of CO can survive around a star for only a brief time, about 100 years, before being destroyed by UV radiation," said Bill Dent, a researcher at the Joint ALMA Office in Santiago, Chile, and lead author on a paper published in the journal Science online at the Science Express website. "So unless we are observing Beta Pictoris at a very unusual time, then the carbon monoxide we observed must be continuously replenished."

Comets and other icy bodies trap vast amounts of CO and other gases in their frosty interiors. When these objects collide, as is common in the chaotic environment around a young star, they quickly release their stored gases. If these collisions were occurring randomly in this system, then the CO would be more or less evenly distributed.

But the new images from ALMA show something else: a single compact clump of CO approximately 13 billion kilometers (8 billion miles) from the star -- or about three times the distance of Neptune to the Sun. "This clump is an important clue to what's going on in the outer reaches of this young planetary system," says Mark Wyatt, an astronomer at the University of Cambridge and coauthor on the paper.

Earlier observations of Beta Pictoris with other telescopes revealed that it is surrounded by a large disk of dusty debris and harbors at least one planet orbiting approximately 1.2 billion kilometers (750 million miles) from the star.

The new ALMA data suggest, however, that there may be a second, as-yet-undetected planet orbiting much farther out. The gravity from such a planet would shepherd millions of cometary bodies into a relatively confined area. A similar phenomenon is seen in our own Solar System where the planet Jupiter keeps a group of so-called Trojan asteroids in a confined orbit around the Sun.

"To get the amount of CO we observed -- which is equal to about one-sixth the mass of Earth's oceans -- the rate of collisions would be truly startling, with the complete destruction of a large comet once every five minutes," noted Aki Roberge, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and coauthor on the paper. "To get this number of collisions, this would have to be a very tight, massive swarm."

The astronomers propose an alternate possibility for the origin of this swarm of icy bodies; two Mars-size icy planets smashing together within the past million years could have produced the compact, cometary debris around the star. Such an occurrence, however, would be rare and there is a low likelihood that it could have occurred recently enough for the remnants to still be so concentrated.

Both possibilities, however, give astronomers reason to be optimistic that there are many more planets waiting to be found around Beta Pictoris, which is located a relatively nearby 63 light-years from Earth in the southern constellation Pictor.

ALMA's unprecedented resolution and sensitivity enabled the astronomers to detect the faint millimeter-wavelength light emitted by both the dust grains and CO in the system.

"And carbon monoxide is just the beginning; there may be other more complex pre-organic molecules released from these icy bodies," adds Roberge.

The astronomers hope that further observations with ALMA will shed more light on this system and help us understand what conditions were like during the formation of our own Solar System.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.


Story Source:

The above story is based on materials provided by National Radio Astronomy Observatory. Note: Materials may be edited for content and length.


Journal Reference:

  1. W. R. F. Dent, M. C. Wyatt, A. Roberge, J.-C. Augereau, S. Casassus, S. Corder, J. S. Greaves, I. de Gregorio-Monsalvo, A. Hales, A. P. Jackson, A. Meredith Hughes, A.-M. Lagrange, B. Matthews, and D. Wilner. Molecular Gas Clumps from the Destruction of Icy Bodies in the β Pictoris Debris Disk. Science, 2014 DOI: 10.1126/science.1248726

Cite This Page:

National Radio Astronomy Observatory. "Icy wreckage discovered in nearby planetary system." ScienceDaily. ScienceDaily, 6 March 2014. <www.sciencedaily.com/releases/2014/03/140306142550.htm>.
National Radio Astronomy Observatory. (2014, March 6). Icy wreckage discovered in nearby planetary system. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2014/03/140306142550.htm
National Radio Astronomy Observatory. "Icy wreckage discovered in nearby planetary system." ScienceDaily. www.sciencedaily.com/releases/2014/03/140306142550.htm (accessed July 29, 2014).

Share This




More Space & Time News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com
NASA EDGE: OCO-2 Launch

NASA EDGE: OCO-2 Launch

NASA (July 25, 2014) NASA EDGE webcasts live from Vandenberg AFB for the launch of the Oribiting Carbon Observatory-2 (OCO) launch. Video provided by NASA
Powered by NewsLook.com
This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
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:
from the past week

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