2010-05-03

Water Ice on Asteriod

Scientists find water-ice and organic material on asteroid


Scientists have for the first time detected water-ice and organic compounds on an asteroid, a discovery which may offer insights into how life started on Earth.

They detected a significant amount of ice on a large asteroid called 24 Themis, which lies between Mars and Jupiter.


Asteroid

Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are smaller than planets but larger than meteoroids. The term "asteroid" has historically been applied primarily to minor planets of the inner Solar System, as the outer Solar System was poorly known when it came into common usage. The distinction between asteroids and comets is made on visual appearance: Comets show a perceptible coma while asteroids do not.


Asteroid coated with ice suggests ingredients for life came from space

Asteroid 24 Themis and two small fragments resulting from an impact more than 1bn years ago. Scientists were surprised to find ice and organic chemicals on the asteroid's surface. Artist's impression: Gabriel Pérez/Servicio MultiMedia

The discovery supports the idea that asteroids may have brought plentiful supplies of water and organic material to Earth in the distant past and so set the stage for the emergence of life.

Two independent groups confirmed the composition of the asteroid's surface after observing the 200km-wide rock using Nasa's Infrared Telescope Facility (IRTF) which sits on the summit of Mauna Kea in Hawaii.

themis_hielo.mov


Universum2010 — May 02, 2010 — (24) Themis is a 200 km wide -- and hence one of the largest -- asteroids in the main belt between the orbits of Mars and Jupiter. Recent observations show, that its complete surface is frosted with water ice, containing a number of additional carbon-based organic compounds. Themis has small "moons" with cometary activity whose tails are thought to be formed by dust and the evaporation of ice. Animation credits: Gabriel Pérez, IAC



Discovery of asteroid water hints at oceans' origins

Scientists from the University of Central Florida (UCF) have detected a thin layer of water ice and organic molecules on the surface of the asteroid 24 Themis, a finding that adds weight to the theory that Earth's oceans resulted from an ancient asteroid impact. The unexpected findings are to be published in Nature.

"What we've found suggests that an asteroid like this one may have hit Earth and brought our planet its water," mused UCF Physics Professor Humberto Campins, the study's lead author. Some scientists have previously suggested that asteroids brought water to Earth after the planet formed dry and the salts and water that have been found in some meteorites do support this theory.



Sources:
  1. BBC World Service - News - Scientists find water-ice and organic material on asteroid
  2. Asteroid - Wikipedia, the free encyclopedia
  3. Asteroid coated with ice suggests ingredients for life came from space | Science | guardian.co.uk
  4. YouTube - themis_hielo.mov
  5. Discovery of asteroid water hints at oceans' origins
Related:
  1. Water Ice Found on the Surface of an Asteroid for the First Time: Scientific American
  2. BBC News - Asteroid Themis has 'frosted surface'
  3. Ice Discovered on Asteroid, Suggests Earth’s Oceans Came From Space | Wired Science | Wired.com
  4. (24) Themis
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