where there’s liquid water..

More science news.. [*ahem* – Ed] Whilst some people have leapt to a somewhat dubious conclusion, it is a remarkable achievement by the astronomers using the ESO 3.6m telescope in Chile to identify the effects of the smallest exo-planetary mass yet detected, only 5 times the mass of the Earth and approximately 50% larger in diameter. It’s part of a three exo-planet system orbiting a star, Gliese 581, in the constellation of Libra just 20.5 light years away. The reason for the excitement is that, despite being close enough to the star to complete an orbit in only 13 days, the exo-planet lies in what is known as the habitable zone – with an average surface temperature of between 0-40 degrees Celsius water would exist as a liquid.. and where there’s liquid water.. there’s [possibly] life.And they’ve thoughtfully provided a YouTube video report

Extra detail from the ESO press release


[1]: Using the radial velocity method, astronomers can only obtain a minimum mass (as it is multiplied by the sine of the inclination of the orbital plane to the line of sight, which is unknown). From a statistical point of view, this is however often close to the real mass of the system. Two other systems have a mass close to this. The icy planet around OGLE-2005-BLG-390L, discovered by microlensing with a network of telescopes including one at La Silla (ESO 03/06), has a (real) mass of 5.5 Earth masses. It, however, orbits much farther from its small host star than the present one and is hence much colder. The other is one of the planets surrounding the star Gliese 876. It has a minimum mass of 5.89 Earth masses (and a probable real mass of 7.53 Earth masses) and completes an orbit in less than 2 days, making it too hot for liquid water to be present.

[2]: Gl 581, or Gliese 581, is the 581th entry in the Gliese Catalogue, which lists all known stars within 25 parsecs (81.5 light years) of the Sun. It was originally compiled by Gliese and published in 1969, and later updated by Gliese and Jahreiss in 1991.

[3]: This fundamental observational method is based on the detection of variations in the velocity of the central star, due to the changing direction of the gravitational pull from an (unseen) exoplanet as it orbits the star. The evaluation of the measured velocity variations allows deducing the planet’s orbit, in particular the period and the distance from the star, as well as a minimum mass.

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  • Cromwell

    Can you drink the water?
    Do they have tea-begs?
    Can you get brown sauce?

  • Ian Scarte

    Wonderfully exciting news.

    Now let me see…20.5 light years away… that’s…hmmm. 187,000 miles, multiplied by 60 to get the distance light travels in one minute, multiplied by 60 to get the distance travelled in one hour, multiplied by 24, multiplied by 365, multiplied by 20.5, gives me…


    (Brain explodes, along with calculator)

  • Cromwell

    When I tried to do that my calculator just said “80085”!

  • But are they Catholic aliens or Protestant aliens?

  • jaffa


    But I would start from here.

  • jaffa


  • Cromwell

    They are Aliehuns!
    I could tell by the smell of soap & eyes too far apart.

  • Cromwell

    Sorry, just to qualify, that wasnt when they gang-probed me last night!

  • Rory

    Isn’t water always liquid? Frozen it is called ice and as a gas it is known as steam. Or so I believe.

  • Oh, frozen H2O then Rory.


  • DK

    The solar system is a Securocrat plot. Look at the Planets: Jupiter and Saturn, the two biggest, are Orange. Mars is red, next to Earth which is blue and Venus, with all those clouds, is white. Red White and Blue.

    Truly the solar system is simply a massive 12th of July parade. And the Sun is the bonfire.

  • eranu

    “just 20.5 light years away.”

    thank goodness, i thought it was going to be miles away !!
    the problem with other stars is that we have no technology that could get us there in a reasonable time. all we have is a few theoretical ideas about how we could travel to other stars, and they all involve technology thats well beyond us at the min. we’re still using chemical explosions to explode our way into orbit…

    best we can hope for is a ride on a virgin plane to the outer atmosphere of our own planet.

  • DK
    Looks like you might be onto something.
    Seriously though, Space.com has some good articles on the new planet.

  • Poor people, a 13 day year. As if Christmas didn’t come round fast enough!

  • Cormac


    We could also try and pick up any radio signals – I believe SETI will be pointing their antennae that way shortly.

    It takes a LONG time for radio/TV signals to travel to even the nearest stars. Aliens may one day land here armed with only the vocabulary from early Coronation St…

    …a saucer lands and a voice intones ‘Ay up, chuck!’

  • It takes 20.5 years for radio and TV signals to reach a planet that is 20.5 light years away. (Sorry for stating the obvious.) The poor aliens probably think that mullets, sleeveless Wrangler waistcoats and Bon Jovi are still cool. And that people actually watch Dallas.

  • It’s very interesting that Gliese 581is an M-class star, since it’s been suggested that these red dwarfs are unlikely to have potentially habitable planets. Given that these stars are among the most common in the universe, the fact that one has now been found must have significant implications for the Drake equation.

  • Pete Baker


    It would certainly seem to have implications for one of the factors in the Drake Equation, fp – the fraction of stars which have planets.

    But I’d suggest that the other factors remain sufficiently undetermined to leave any value arrived at through the Drake Equation in the realms of educated guess-work.

  • pugachev

    So whats going to happen if they come to visit us first ?

  • Pete,

    Maybe also ne, the average number of planets that can potentially support life per star that has planets.
    Until recently, the argument was that even if red dwarf stars had planets they would be unlikely to be able to support life. Gliese 581c seems to support the reassessment of that view, although I don’t know if there’s anyway to determine if its tidally locked.
    It’s all very speculative, no doubt, but there could be a lot of new data in the next few years with the number of missions planned looking at extra-solar planets. Corot has already launched. Kepler is due in 2008. Hopefully Darwin and the Terestrial Planet Finder will follow.

  • Pete Baker


    I doubt that the radial velocity detection method, used in this case, would be able to provide any evidence of an exo-planet’s own motion. I’m not sure that there would be any way to determine that beyond direct observation.

    But of more relevance to the factor ne is the issue of flare-activity with M dwarfs.. particularly with an orbit so close to the star.

    I’m not convinced, however, that the Drake Equation is an appropriate way to assess the potential existence of life, intelligent or otherwise, elsewhere.

  • IJP


    Then we need to keep it tight at the back and not concede an away goal.

  • ‘I’m not convinced, however, that the Drake Equation is an appropriate way to assess the potential existence of life, intelligent or otherwise, elsewhere.’
    I agree Pete, given that the Drake equation was based on guesstimates, assumed values and, worse still flawed logic (that a question such as preponderence of life can be statistically determined. and since the Drake equation was first postulated the observational data has taken some turns not accounted for…but its a fun vision of aliens listening to Bon Jovi…as long as it isn’t The Smiths “Not visiting that bloody grumpy planet”…hang on maybe that’s why they’re not talking to us!

  • jaffa

    I just tried to work out how many potential friends we have in the galaxy with this Drake thing and my assumptions seem to say that we on Earth only have a 1/100th chance of existing.





  • Damn that could explain a lot (couldn’t explain NI’s politics though…)

  • Rory

    How, I wonder would this Drake’s Equation thingy be best applied to assist a fellow to find a suitable partner for willing congress after closing time on a Friday evening? If it cannot help along this process then I predict a very limited future for it as a tool for assisting or predicting the procreation of life.

    No doubt Sammy Morse will now show me where I have gone wrong – much as mother predicted.

  • Truth & Justice

    it would be interesting to see if any of the aliens would vote UUP maybe the postal votes would help them?

  • eranu

    if they’re little green men then they’d probably be shinners 🙂

  • kensei

    “But I’d suggest that the other factors remain sufficiently undetermined to leave any value arrived at through the Drake Equation in the realms of educated guess-work.”

    I’d go further and suggest they are entirely meaningless. There are so many other factors that might go into determining if life will getting going and more in terms of evolution – the tilt of the planet, tectonic and volcanic activity, precise chemical composition, variation in climate, extinctions at the right time etc that much of the Drake equation isn’t just unknown, but unknowable.