Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clouds of molten droplets in the early solar system?

12.10.2007
Comets and asteroids are a small but important part of the Solar System. Scientists have long debated how they formed: did their component grains accrete from the cloud of gas and dust – the solar nebula - that encircled the Sun at the beginning of the Solar System or did they undergo melting due to violent impacts and the presence of short-lived radioactivity?

On October 12th delegates attending the Royal Astronomical Society (RAS) meeting ‘Early Solar System Processes on Meteorites’ will discuss the competing theories. The meeting is being held in honour of the late Robert Hutchison, who was a distinguished meteorite expert at the Natural History Museum and used early Solar System samples to deduce how asteroids formed.

One group of scientists believes that the partial melting of asteroids led to the formation of chondrules, mm-size melt droplets which make up many meteorites. Another camp is convinced that asteroids grew from cold particles in the solar nebula and that the chondrules formed beforehand. There are currently two main ways of studying this question: one is to analyse the composition and age of primitive meteorites, the other makes use of similarly primitive grains collected from Comet Wild-2 by the NASA Stardust space probe, which returned a sample to Earth in January 2006.

Like other comets, Wild-2 began life in the earliest stages of the Solar System, more than 4500 million years ago. At that time the rocky, metallic and icy material that ultimately formed the planets started to form larger bodies. Ices of water, ammonia, carbon dioxide and carbon monoxide condensed in the cold outer parts of the Solar System. Most of the ices ended up as part of the gas giant planets – Jupiter, Saturn, Uranus and Neptune – but some remained in much smaller bodies 1-10 km across that eventually formed the cores (nuclei) of comets.

Comets that have spent most of their lives at a great distance from the Sun contain the least processed material in the Solar System, whereas in contrast an increasing number of scientists believe that asteroid surfaces were extensively melted. For example, one theory put forward by Dr Ian Sanders of Trinity College Dublin is that the presence of radioactive material created enough heat to partially melt the building blocks of planets and asteroids (planetesimals) found in the early Solar System. When these objects collided they would have created great clouds of molten droplets, the predecessors of the material found in asteroids today.

Meeting chair Dr John Bridges of the University of Leicester is part of the international team studying grains from Wild-2 and hence the early history of the Solar System. Dr Bridges comments ‘There has been a vigorous debate for many years about how the earliest planetesimals formed – either from cold accumulation of dust and gas from the nebula and interstellar space or through impact and radioactivity-induced melting. By studying Comet Wild-2 and primitive meteorites we are starting to reveal the true nature of a violent early Solar System where many of the earliest planetary building blocks underwent repeated collisions and melting episodes.’

Robert Massey | alfa
Further information:
http://www.ras.org.uk

More articles from Event News:

nachricht Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru
28.04.2017 | InfectoGnostics - Forschungscampus Jena e.V.

nachricht Expert meeting “Health Business Connect” will connect international medical technology companies
20.04.2017 | IVAM Fachverband für Mikrotechnik

All articles from Event News >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>