Open

Coming up

Don't miss

Replay


LATEST SHOWS

TALKING EUROPE

Nigel Farage, Leader of the UK Independence Party

Read more

TALKING EUROPE

Endocrine disruptors: Is the EU doing enough to protect its citizens' health?

Read more

WEB NEWS

Israelis taking bomb shelter selfies

Read more

THE INTERVIEW

Pavlo Klimkin, Ukrainian Foreign Minister

Read more

THE INTERVIEW

Raed Fahmi, former Iraqi Minister of Science and Technology

Read more

IN THE PAPERS

Germany's World Cup title

Read more

FASHION

Paris, Haute Couture Fall/Winter 2014-2015

Read more

BUSINESS DAILY

Farnborough air show takes off but F-35 jet is grounded

Read more

IN THE PAPERS

Bastille Day celebrations

Read more

  • Boules and booze: Bastille Day à la New Yorkaise

    Read more

  • In pictures: 2014 World Cup historic moments

    Read more

  • Kremlin mulls 'retaliatory strikes' after death of Russian civilian

    Read more

  • France commemorates WWI centenary on Bastille Day

    Read more

  • Paris’s Bastille Day fireworks ‘a homage to victims’ of WWI

    Read more

  • Shipwrecked Costa Concordia successfully refloated

    Read more

  • Germany defeat Argentina 1-0 to win fourth World Cup title

    Read more

  • Senegal honours the soldiers who fought for France in WWI

    Read more

  • Clashes erupt in Paris as thousands march to support Palestinians

    Read more

  • Thousands flee northern Gaza after Israeli warning

    Read more

  • Major differences remain as deadline looms in Iran nuclear talks

    Read more

  • Rival Libyan militias exchange heavy fire at Tripoli airport

    Read more

  • French military to extend Mali 'counterterrorism' operations into Sahel

    Read more

Earth-like exoplanet may be able to support life

©

Latest update : 2009-04-28

A group of scientists have made two major discoveries in the quest to find life in space by localizing a new exoplanet called "Gliese e", the smallest of its kind, and by realising that nearby "Gliese d" might be a candidate for supporting life.

AFP - Astronomers unveiled Tuesday the lightest exoplanet ever detected and, in the same distant solar system, the first "serious candidate" for a world with abundant liquid water, both conditions essential for supporting life.
  
"I would put the two discoveries on an equal footing," said Thierry Forveille, an astronomer at the Grenoble Observatory in France and a co-author of the study.
  
"The holy grail of exoplanet research is to find a planet that combines both, the approximate mass of Earth and conditions favourable for water. Here we have each separately, but we are getting closer," he told AFP by phone.
  
The newly detected smaller body, dubbed Gliese 581 "e", has a mass only twice that of Earth.
  
This makes it the smallest of the nearly 350 exoplanets found so far, and means it probably has a rocky surface not unlike our own.
  
Beyond a certain size, exoplanets become giant balls of toxic gas, similar to Jupiter.
  
Nearby Gliese 581 "d" is seven times heavier than our planet, and the composition of its surface is unknown.
  
But new calculations -- made possible by the discovery of "e" -- show that the larger planet is squarely within the so-called "habitable zone," neither too far nor too close to the star around which it orbits to support life.
  
"Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to its star," said co-author Stephane Udry, a professor at Geneva University.
  
"It could even be covered by a large and deep ocean -- it is the first serious 'waterworld' candidate," he said in a statement.
  
With an orbit only 3.15 days long, Gliese e orbits close to its star and is almost certainly a white-hot, fiery mass.
  
The new findings, slated for publication in the journal Astronomy and Astrophysics, were obtained using the most successful low-mass-exoplanet hunter in the world, the HARPS spectrograph attached to the 3.6-metre ESO telescope at La Silla, Chile.
  
Gliese 581, located some 20.5 light-years distant in the constellation Libra, falls into the category of low-mass, red dwarf stars, around which low-mass planets in the habitable zone are most likely to be found.
  
One light-year is roughly equivalent to 9.5 trillion kilometres (6 trillion miles).
  
Distant planets, even big ones, are too small to be directly observed, and can only be detected by measuring their impact on the movement of the stars they orbit.
  
The first exoplanet -- 51 Pegasi b -- was detected in 1995. Almost all those discovered to date are large gas giants.
  
"It is amazing to see how far we have come since then," said lead researcher Michael Mayer, also of Geneva University. "The mass of Gliese 581 e is 80 times less than that of 51 Pegasi b," he said.
  
Planets are formed from a disc of gas and dusty debris left over from the creation of a star. Just how long this process takes is still a matter of debate.
  
Earth is believed to be about 4.5 billion years old, and the Sun about 100 million years older.

Date created : 2009-04-22

Comments

COMMENT(S)