Monday, September 19, 2011

Super-Earths and Binary Suns

My latest piece for, as suggested by editor Ze, is on newly-discovered planets "out there". Here's how it starts:

A planet orbits a faraway star. Although it’s light it tugs on its parent sun, so that sometimes the star is pulled slightly towards us, and sometimes pushed away. How can we tell? That tiny orbital-wiggle creates a slowly-oscillating Doppler shift in the frequency of the starlight we see.

It sounds like a tiny effect and it is, but HARPS (the High Accuracy Radial Velocity Planet Searcher) can measure stellar radial velocities to an accuracy of 1 meter per second – and that’s enough for some new discoveries. HARPS has just found 16 super-Earths, exoplanets with a mass not much higher than our own.

The most promising of the newcomers is the planet HD 85512 b, around 3.6 times the mass of the Earth. Its surface gravity is estimated to be around 1.4 g and its climate similar to the south of France, although some observers suggest it’s a trifle muggy. It’s the best exoplanet yet for the prospects of habitability and at a mere 36 light years away, it’s practically in our backyard.
... more.

I find that the documentary-style science narratives don't go down particularly well with the audience, as measured in "Likes". I have 500 - 1,000 words to play with and the most "liked pieces" tend, not surprisingly, to be about topics which plug into the topical interests of the readers and which have a story-telling element. But any dramatist could tell you that!
The weather has continued to be uniformly dreadful: warm enough but with gloomy overcast skies and frequent showers. We've been hibernating with just forays out to the shops. Last Friday was exceptional, as noted in recent posts, when we were chasing the Tour of Britain cycling race around our local area. Clare is generally getting stronger although she dips out in the afternoons.