Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UK astronomers observe asteroid before it crashes into Earth

30.03.2009
UK astronomers, using the Science and Technology Facilities Council's (STFC) William Herschel Telescope on La Palma, observed a rare asteroid as it was hurtling towards our planet and have captured the only spectrum of it before it exploded in our atmosphere.

This is the very first time that an asteroid that hit the Earth has been studied before entering our atmosphere, allowing the scientists to predict whether it would explode and break up in the atmosphere or reach the ground – which determines whether an asteroid poses any threat. The results of the international collaboration studying the asteroid are published in this week's (March 26th) issue of Nature.

The asteroid in question - 2008 TC3 - an 80 tonne, 4 meter asteroid with a rare composition, was first sighted by US telescopes on 6th October 2008. Subsequent observations by an international army of professional and amateur astronomers led to the discovery that it was racing towards our planet and was due to enter the atmosphere the following morning.

"This was the first ever predicted impact of an asteroid with the Earth and the very first time an asteroid of any size has been studied before impact," said Prof. Alan Fitzsimmons, from the Queen's University Belfast. "The faint observed brightness implied a small size, which in turn meant there was little advance warning. It was important to try and figure out what type of asteroid it was before impact, which would give us a better idea of its size and where it came from. This event shows we can successfully predict the impact of asteroids even with a short warning time, and obtain the astronomical observations necessary to estimate what will happen when the asteroid reaches us."

The spectrum gathered by the UK astronomers allowed them to obtain information on the size and composition of the asteroid and to establish the first direct link between an asteroid and the individual meteorites produced as it breaks up in our atmosphere. Not only does this help to validate the whole process of remotely surveying asteroids but comparing the asteroid and meteorite data tells us that 2008 TC3 may have only spent a few million years existing in the Inner Solar system before it hit our planet.

The team that observed the asteroid were already at the telescope when they got the news of its approach. Only 4 and a half hours before impact, they were able to use the ISIS spectrograph on the William Herschel Telescope to measure how light reflected from its surface.

Sam Duddy from Queen's University Belfast explained, "When we found we could observe the asteroid from the telescope it was an exciting couple of hours planning the details of the observations we would conduct. Actually performing the observations of an object that was certain to impact the atmosphere was a great but challenging experience."

"These observations were technically quite difficult since the object was moving fast across the sky," said Dr. Gavin Ramsay from Armagh Observatory. "However, the William Hershel Telescope rose to the challenge magnificently and demonstrated just what a versatile telescope it is. There was a keen sense of excitement in the control room."

Some small fragments survived the high-altitude explosion that vapourised most of the asteroid. The lead author of the article, astronomer Dr. Peter Jenniskens of the SETI institute in California, teamed up with Dr. Muawia Shaddad and 45 students and staff of the University of Khartoum to search the Nubian Desert in Sudan for meteorites. In the first search campaign on 5th-8th December, 15 meteorites were recovered over an area 29 km long along the calculated approach path of the 4-meter sized asteroid. In later searches, a total of 4 kg of meteorites was found, which still accounts for only a small fraction of the 80 tonnes that crashed into the Earth's atmosphere.

"This asteroid was made of a particularly fragile material that caused it to explode at a high 37 km altitude, before it was significantly slowed down, so that the few surviving fragments scattered over a large area," explains Dr. Peter Jenniskens of the SETI institute in California. "The recovered meteorites were unlike anything in our meteorite collections up to that point."

After measuring how the meteorites reflected light, it was discovered that the spectra of the asteroid and meteorites agree well, which implies that the asteroid was not covered in dust and did not have much weathering from radiation in space. More importantly, the team found that 2008 TC3 was a rare type of asteroid, called F-class, corresponding to dark ureilite achondrite meteorites with a texture and composition unlike any other ureilite meteorites found on Earth before.

Prof. Richard Crowther of the Science and Technology Facilities Council (STFC) and Chair of the UN Working Group that deals with near earth object (NEO) threats said, "The search for and study of asteroids is extremely important as not all impacts are as harmless as this small one in October. Larger impacts of the size associated with the Tunguska event of 1908 occur every few hundred years and even larger impacts with asteroids and comets the size of mountains occur every few tens of millions of years. Any extra knowledge we can gain about asteroids will help us mitigate the potential effects of such impacts in the future."

Julia Short | EurekAlert!
Further information:
http://www.stfc.ac.uk

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>