Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Close encounters of another kind?

03.09.2003


The latest discovery of a large asteroid moving through our Solar System puts a spotlight on the studies of these and other wandering celestial objects by the European Space Agency.



Some astronomers have predicted that this newly discovered object could hit the Earth on 21 March, 2014, but now data indicate that the chances of it doing so are really very small - less than one in 909,000.

However, scientists continue to monitor these objects which could give clues to the origins of our Solar System. ESA’s Infrared Space Observatory (ISO) satellite showed that there might be as many as two million asteroids larger than one kilometre in the region of space known as the ’’asteroid belt’’. Gravitational nudges from the planets can push them out of position, causing them to fall towards the Sun, which means that they may cross Earth’s orbit and potentially collide with our world.


The planets of the Solar System were born in a violent storm of asteroid-like objects that began 4.6 thousand million years ago and lasted for roughly 500 million years. The planets failed to consume all of the asteroids and the planetary leftovers are still orbiting the Sun today. Most of them are confined to the ‘main belt’ of asteroids, in between the orbits of Mars and Jupiter.

Ironically, this process, which is thought to have initially assisted in life’s origin by seeding the Earth with precious organic compounds, now threatens it.

There are several impact craters visible on the Earth’s surface, one of them is the Haughton crater in Canada, formed 23 million years ago, but many terrestrial craters are now covered by water or forests, or have been eroded away over thousands of years. There is now compelling evidence that the death of the dinosaurs was accelerated by the impact of an asteroid that struck the Earth in the Yucatán peninsula, off the coast of Mexico.

The Earth is in danger not only from asteroid strikes but also from their icy equivalents, comets. They could wreak havoc if they were to collide with our world. These objects usually live far away beyond even Pluto but can be jolted from their usual orbits by passing stars or gigantic gas clouds.

Comets are considered to be the primitive building blocks of the Solar System, and ESA’s Rosetta comet-chasing mission could help us to understand if life on Earth began with the help of ’’comet seeding’’.

The chances of a comet hitting the Earth are also very small, but the possibility does exist, as shown when Comet Shoemaker-Levy 9 collided with Jupiter in 1994. The NASA/ESA Hubble Space Telescope, as well as Earth-based telescopes around the world, obtained spectacular imagery of this first-ever observed collision between two objects in our Solar System.

Hundreds of small comets are spotted every year, but most are drawn towards the Sun by its large gravitational attraction. They are called ’’sungrazer’’ comets and they burn up completely in the Sun’s hot atmosphere.

The ESA/NASA sun-watching spacecraft SOHO has become the most prolific discoverer of comets in the history of astronomy. With its LASCO coronagraph instrument, originally designed for seeing outbursts from the Sun, SOHO can monitor a large volume of surrounding space, and it is now a vital tool for ESA in the study of comets.

Monica Talevi | alfa
Further information:
http://www.esa.int/export/esaSC/SEMCXLZO4HD_foryou_0.html

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>