Subscribe free to our newsletters via your
. 24/7 Space News .

Crashing Comets Explain Surprise Gas Clump Around Young Star
by Staff Writers
Santiago, Chile (SPX) Mar 11, 2014

The position of the star Beta Pictoris is marked with a circle on this chart of the constellation Pictor (The Painter's Easel). As indicated by its name, this is the second brightest star in its constellation. Together with most of the stars marked on this chart, it can be seen in a dark sky with the unaided eye. Image courtesy ESO, IAU and Sky and Telescope. For a larger version of this image please go here.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in northern Chile have today announced the discovery of an unexpected clump of carbon monoxide gas in the dusty disc around the star Beta Pictoris. This is a surprise, as such gas is expected to be rapidly destroyed by starlight.

Something - probably frequent collisions between small, icy objects such as comets - must be causing the gas to be continuously replenished. The new results are published today in the journal Science.

Beta Pictoris, a nearby star easily visible to the naked eye in the southern sky, is already hailed as the archetypal young planetary system. It is known to harbour a planet that orbits some 1.2 billion kilometres from the star, and it was one of the first stars found to be surrounded by a large disc of dusty debris [1].

New observations from ALMA now show that the disc is permeated by carbon monoxide gas. Paradoxically the presence of carbon monoxide, which is so harmful to humans on Earth, could indicate that the Beta Pictoris planetary system may eventually become a good habitat for life. The cometary bombardment that its planets are currently undergoing is likely providing them with life-enabling water [2].

But carbon monoxide is easily and rapidly broken up by starlight - it can only last about 100 years where it is observed in the Beta Pictoris disc. Seeing it in the 20-million year old Beta Pictoris disc is a complete surprise. So where did it come from, and why is it still there?

"Unless we are observing Beta Pictoris at a very unusual time, the carbon monoxide must be continuously replenished," said Bill Dent, an ESO astronomer at the Joint ALMA Office in Santiago, Chile, and lead author on a paper published today in the journal Science.

"The most abundant source of carbon monoxide in a young solar system is collisions between icy bodies, from comets up to larger planet-sized objects."

But the rate of destruction must be very high: "To get the amount of carbon monoxide we observe, the rate of collisions would be truly startling - one large comet collision every five minutes," noted Aki Roberge, an astronomer at NASA's Goddard Research Center in Greenbelt, USA, and coauthor of the paper.

"To get this number of collisions, this would have to be a very tight, massive comet swarm."

But there was another surprise in the ALMA observations, which did not just discover the carbon monoxide, but also mapped its location in the disc, through ALMA's unique ability to simultaneously measure both position and velocity: the gas is concentrated in a single compact clump. This concentration lies 13 billion kilometres from the star, which is about three times the distance of Neptune from the Sun. Why the gas is in this small clump so far from the star is a mystery.

"This clump is an important clue to what is going on in the outer reaches of this young planetary system," says Mark Wyatt, an astronomer at the University of Cambridge, UK, and a co-author on the paper.

He goes on to explain that there are two ways such a clump can form: "Either the gravitational pull of an as yet unseen planet similar in mass to Saturn is concentrating the cometary collisions into a small area, or what we are seeing are the remnants of a single catastrophic collision between two icy Mars-mass planets".

Both of these possibilities give astronomers reason to be optimistic that there are several more planets waiting to be found around Beta Pictoris. "Carbon monoxide is just the beginning - there may be other more complex pre-organic molecules released from these icy bodies," adds Roberge.

Further observations are planned with ALMA, which is still ramping up to its full capabilities, to shed more light on this intriguing planetary system, and so help us to understand what conditions were like during the formation of the Solar System.

[1] Many stars are surrounded by swirling clouds of dust, known as debris discs.They are the remains of a collisional cascade of the rocks in orbit around the star, much like the collisional breakup of the space station depicted in the movie Gravity (but on a much larger scale). Earlier observations of Beta Pictoris were reported in eso1024 and eso0842.

[2] Comets contain ices of carbon monoxide, carbon dioxide, ammonia and methane, but the majority component is a mixture of dust and water ice.

Science paper


Related Links
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

A small step toward discovering habitable earths
Tucson AZ (SPX) Mar 09, 2014
University of Arizona researchers snapped images of a planet outside our solar system with an Earth-based telescope using essentially the same type of imaging sensor found in digital cameras instead of an infrared detector. Although the technology still has a very long way to go, the accomplishment takes astronomers a small step closer to what will be needed to image earth-like planets around ot ... read more

Russia to launch three lunar rovers from 2016 to 2019

Control circuit malfunction troubles China's Yutu

China's Lunar Lander Still Operational

China Focus: Uneasy rest begins for China's troubled Yutu rover

India's Mars mission to reach Red Planet in 200 days

Opportunity Mars Rover Exploring Murray Ridge Area

Mars Rover Oppportunity Crushing Rocks With Wheels

Relay Radio on Mars-Bound NASA Craft Passes Checkout

Bright pulses of light could make space veggies more nutritious

Mini Rocket Models to be Used in a Big Way for SLS Base Heating Test

Under shadow of spy scandal, Merkel, Cameron head to tech fair

Committee Democrats Emphasize Need for Human Space Exploration Roadmap

China to launch first "space shuttle bus" this year

Feature: The "masters" behind China's lunar rover Jade Rabbit

China expects to launch cargo ship into space around 2016

China capable of exploring Mars

Japanese astronaut becomes ISS commander

American, two Russians back on Earth after half-year in space

Station Crew Preps for Return to Earth, Repairs Recycling System

NASA says US-Russia space ties 'normal'

Payload prep continues for Arianespace Soyuz for Sentinel-1A

Russia to Start Building New Manned Rocket Launch Pad in 2015

New Vostochny space center a key priority for Russian Far East

'Mission of Firsts' Showcased New Range-Safety Technology at NASA Wallops

Every red dwarf star has at least one planet

Galactic gas caused by colliding comets suggests mystery 'shepherd' exoplanet

'Dimer molecules' aid study of exoplanet pressure, hunt for life

A small step toward discovering habitable earths

South Africa's nano-satellite encounters space debris

First step towards programmable materials

Australia to prevent 'Gravity' space crash with lasers

Aerojet Rocketdyne Provides Propulsion For GPM Satellite

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.