Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

COROT and the new chapter of planetary searches

15.11.2006
The launch of COROT on 21 December 2006 is a long awaited event in the quest to find planets beyond our Solar System. Searching from above the Earth's atmosphere, COROT – the CNES project with ESA participation - will be the first space mission specifically dedicated to the search for extrasolar planets.

COROT is expected to greatly enlarge the number of known exoplanets during its two-year mission and provide the first detection of rocky planets, perhaps just a few times the mass of the Earth.

"COROT could detect so many planets of this new type, together with plenty of the old type that astronomers will be able to make statistical studies of them," says Malcolm Fridlund, ESA's Project Scientist for COROT.

This will allow astronomers to more accurately predict the number and type of planets that will be found around other stars.

The world of astronomy changed forever on 6 October 1995, when Michel Mayor and Didier Queloz of the Geneva Observatory announced the first discovery of a planet around a star similar to the Sun. As well as celebration, there was surprise because 51 Pegasi b, as the planet became known, was half the mass of Jupiter and orbiting much closer to its parent star than expected. Whereas Mercury orbits the Sun at 57.9 million kilometres in 88 days, 51 Pegasi b shoots around its orbit in just 4.23 days. This indicated that the planet was just 7.8 million kilometres from its star.

An American team led by Geoff Marcy, San Francisco State University, and Paul Butler, University of California, Berkeley, soon discovered other planets around other stars. They too were large, Jupiter-like planets in extremely close orbits.

These planets had not been seen directly. Instead, their presence had been inferred by the gravitational pull they exerted on their parent star. The astronomers had measured the wobble of the star through changes in its light, and used this data to calculate the orbit and minimum mass of the planet.

COROT relies on a new way of detecting planets. As tens of thousands of people witnessed on 8 June 2004, a planet moving across the face of the star creates a noticeable silhouette. On that day, onlookers watched the black dot of Venus slip across the Sun’s bright surface.

COROT is designed to detect such transits of extrasolar planets across the faces of their parent stars. It will monitor the brightness of stars, looking for the slight drop in light caused by the passage of the planet. Because this relies on the chance alignment of the star and the planet with Earth, a large number of stars must be monitored to make certain of seeing enough events. COROT will monitor hundreds of thousands of stars. "The first target field is towards the galactic centre. Then the spacecraft will turn towards Orion," says Fridlund.

COROT will be the first extrasolar planet search mission capable of seeing the smaller, rocky worlds; although they will have to be in close orbits around their stars. COROT also opens the way for the future. Two years later, in October 2008, NASA will launch Kepler, a space telescope with a 0.95 metre mirror. Kepler works the same way as COROT, looking for planetary transits, and is expected to find the first Earth-sized planets in similar orbits to our world.

Following Kepler, a new technique will be needed. The problem is that the larger the telescope's mirror, the smaller its field of view becomes. So building a larger telescope to reach fainter stars means restricting the area of sky it looks at. Although seeing fainter stars brings gains, the field of view shrinks, leaving fewer stars in total available.

Claude Catala, Observatoire de Paris-Meudon, amongst others has proposed a method that may solve this problem. Instead of a larger space telescope with a smaller field of view, the new proposal uses hundreds of 10-cm telescopes in parallel.

Each telescope is smaller than most amateur astronomers use on Earth but each has a wide field of view, 30 degrees across. That’s about 60 times the width of the full Moon. Because they are so small, each tiny telescope is incapable of collecting enough light on its own to make a useable image. However, a computer on the proposed spacecraft would combine the faint images recorded by each tiny telescope. This would give enough information to detect transits. Thus, the future of detecting planetary transits may be to launch a spacecraft that contains hundreds of mini-telescopes.

After this, the next big leap in planetary searches is likely to be the isolation of reflected light from a planet. This would allow the planet’s atmosphere to be chemically analysed. In the case of an Earth-like world, the analysis could reveal signs of life. ESA is currently developing the necessary technology to make such a mission possible. They are developing it under the name of Darwin, to be possibly launched after 2020.

Malcolm Fridlund | alfa
Further information:
http://www.esa.int/esaSC/SEMCBN0CYTE_index_0.html

More articles from Physics and Astronomy:

nachricht Creative use of noise brings bio-inspired electronic improvement
26.09.2017 | American Institute of Physics

nachricht The fastest light-driven current source
26.09.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>