Weird Planets

exoplanetThis year has produced some amazing discoveries in the planet-hunting arena.

Notable among these is the announcements of more ‘super-Earths’.

The planet HD 40307g is the most distant from its sun of six planets found in its system, and takes 200 days to orbits its star. At seven times Earth-mass, bets are on as to whether this planet is rocky or a Neptune-like world. Astronomers put it at about 50:50. The system is around 42 lightyears away. Not only does it orbit in a habitable zone, the target system is also close enough to potentially image directly in the future using the next generation of space-based telescopes. Bring it on!

Gilese 163c is another planet in its stars habitable zone, also estimated at seven times the mass of the Earth. The planet orbits a red dwarf slightly dimmer than old Sol and zips around it in 26 days [red dwarfs are the most common star type in the Milky Way].

Other discoveries showed planets where you least expect to find them – in multiple star systems. Solving multiple-body problems like that give even the most brilliant mathematicians a severe headache. But that does not stop us from seeing what’s out there.

The gas giant PH1orbits a pair of stars that are part of a four-star system [in this case it would orbit the centre of mass of the two stars]. The first planet found in a four-star system. It is bigger than Neptune, and easily big enough to host rocky moons approaching Earth-size. Unfortunately its location makes it too hot for liquid water – its temperature is estimated to range between 251C to 340C (484-644F).

The best thing about PH1 is that it was discovered by two amateur astronomers as part of the Planet Hunters program. So non-professionals get to play too!

A number of binary systems with planets have now been found, some with planets near the habitable zone, such as Kepler-34b and Kepler 35b. Each would get that double-star sunrise, just like Tatooine. Both planets are big, and around 5000 lightyears from Earth. So no exploring just yet.

As for the closest planet, that is a rocky planet orbiting Alpha Centauri B, 4.2 lightyears from Earth. No need to pack the swimsuit – unless you like doing laps in lava. It orbits its sun in a little over 3 days at a distance one tenth of Mercury’s orbit. Ouch.

What were your favourite discoveries of the year?

Cross-posted at chrismcmahons blog.


  1. The Alpha Centauri B planet delighted me. Now we just need a few more, further out, and some around the A component, and we’ll have the best possible target for our first interstellar venture. All we need is speed . . .

  2. As much as hate to say it, I think humanty’ spread is going to be slow. It might take a century just to get to Mars. To go beyond our solar system with current technology. . . ? I’m hoping for a breakthrough in some sort of viable suspension technology, because my best guess is that we are going to be no faster that 0.1C. Then again there is always the possibility of a big physics breakthrough.

    1. I have more hope than that for Mars. If it were up to our governments, sure, 100 years. But it’s not so much anymore. We’re open to the wild card, the visionary, the con artist… the government need not apply. Or if the government does apply, it will be catch-up, an attempt to contain and control the humans who leave.

      The more I think of those first private-funded colonies, the more I think they’ll be an utter disaster. If nothing else the human engineering elements as described are fundamentally wrong, but it could be that the internals of the private efforts are more sane. An example is… we’ll all be vegetarian on Mars. Well, *my* colony will have livestock and a ship cat or two.

      1. That would be nice to see. There have certainly been great efforts in the private space vehicle department. Maybe when the Richard Branstons of the world deliver on the space ride tickets to sub-orbital destinations the uber-rich will start pre-paying tickets on a priavate Mars mission:)

  3. I’d sure like to get an actual measurement of the particles and concentration in interstellar space. The bussard ramjet idea is so cool, and probably not workable at the current estimations of hydrogen density outside the magnetosphere.

    1. Yep. That one had so much promise. The bigget problem I’m aware of is more to do with the build up of charge around the scoop. Basically it seems to function as a really great breaking mechanism – not exactly what you want to accelerate you!

Comments are closed.