Tomas Martin @ 11-03-2008
Tomas Martin @ 07-11-2007
Astronomers have discovered a planet in the 55 Cancri system that orbits constantly in what is know as the ‘habitable zone’ of the solar system. Although the planet is a gas giant some 45 times the size of Earth, there’s a good chance one of its moons might have liquid water and hence encourage the development of earth-like life. Planets are found by studying their transits across the light of a star. By studying the amount the star dims when the planet crosses, the size of the planet can be estimated. This is limited to larger planets currently but future missions like the Kepler and Darwin projects may be able to find rocky planets like our own.
The search for ‘exoplanets’ outside our solar system is hitting its stride and regularly more are found. Whilst the planets found to date are all ‘Jupiters’ like the gas giants further out in our home system, we know that Jupiter, Saturn, Neptune and Uranus all have large satellites. If any of these were in the habitable region where Earth is, the possibility of liquid water and hence bacterial life would be likely. If 55 Cancri did support life on one of its moons it would resemble the world of Coyote in Allen Steele’s excellent series.
[via the guardian, image of Darwin project via Astronomy Online]
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Edward Willett @ 25-09-2007
Doing SF writers’ work for them, a U.S. research team has worked out the properties of a variety of weird planet types that could exist in alien solar systems, including graphite planets and carbon monoxide spheres. Of course, they didn’t do it to help writers (though that would be a fine reason do do such a thing): instead, they hope the models will help astronomers identify the properties of exoplanets they discover in the future.
And yes, say the scientists, weird as these worlds are, some of them could harbour life…though not necessarily Life As We Know It.
(Via New Scientist Space.)
(Illustration: Marc Kuchner/NASA-GSFC via New Scientist Space)
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Paul Raven @ 12-07-2007
This story is everywhere today, but my preferred source for the real unsensationalised science behind astronomy headlines is Centauri Dreams, which explains that, while there is indeed water in the atmosphere of exoplanet HD 189733b, it’s almost certainly not in the liquid form that we are used to finding it in. The good news is that it suggests water-abundant star systems are not a rarity - so maybe one day we’ll find a planet more like our own.
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Alpha Centauri is the closest star system to our own but with a bonus: there are three stars rather than one. It’s also one of the best chances we know in the local area to have a planet similar to Earth capable of developing life like ours.
