NASA kicked off Exoplanet Week with a big announcement from the Kepler space telescope: 219 new planet candidates, fresh-baked for you in the constellation of Cygnus. The haul includes 10 ‘Earth-like’ planets which really got the international press salivating. At this rate we should be expecting a phone call from ET any day now.
So, ten new Earths? That’s pretty exciting, innit?
Not so fast there, pal. The latest news – though very cool – is not quite the cold, hard vindication of Mulder’s paranoia that the press would have you think it is. Yes, the new data contains a whopping ten rocky planets sitting within their ‘habitable zones’ (or was that supposed to be ‘habitual zone’?), but there’s a lot more to the story than that.
Firstly, these new planets are Kepler ‘candidates’. Like PhD candidates, planet candidates have a very good chance of being ‘confirmed’ and becoming bona fide scientists – I mean, ‘exoplanets’ – but some wilt under examination and become ‘unemployed’ – aka ‘diddly squat’. NASA, for all the goodwill I like to direct their way, are very protective of their data and like keep it in-house until they’re ready to extract the juiciest headlines from it. Us barbarians in the colonies must either hang out for late-night press conferences (conveniently held just before California lunchtime) or resort to eavesdropping on the Ames Centre watercooler.
Secondly, the phrase ‘Earth-like’ is misleading. If I asked your average Joan Citizen how many Earth-like planets she could name, I expect she would say just one – Earth. But actually, NASA’s definition of the term ‘Earth-like’ comfortably encompasses four planets in our solar systems alone – Earth, but also Venus, Mars, and even our own Moon (nerds call it ‘Luna’). Clearly only one of these hosts ‘life as we know it’ and you’re probably standing on it right now.
Way to kill the party, man
Hey, don’t get me wrong – this is really exciting news. It’s just not exciting in the way the Independent thinks it is. The coolest thing to come out of the new data (it’s actually rather old data, but that’s a whole other story) is not that the galaxy is choc-a-bloc with sister Earths. Quite the opposite – it’s beginning to look like our solar system is the odd one out. It’s like we’ve been collecting Dragonball Z tazos and pulling nothing but Yamchas and Krillins.
You see, the clever folks at the Ames Research Centre have been digging through the data and have found an interesting pattern. It looks like the cosmos builds heaps of rocky little planets, but most of them come out almost twice the size of our home planet. More intriguing still, about half of these so-called Super Saiyans – I mean, Super Earths – hoover up a whole bunch of water and helium and turn into Neptune-style gas giants (you wouldn’t know it to look at it, but our oft-overlooked blue friend – no, not that one – probably has a big ol’ Earth-like planet under all that cloud). At a Z-team family reunion Earth would die of noogies well before the first bout. (Did I mention I turned 26 recently?)
So the question increasingly on planetary scientists’ lips is: how did we wind up with ten or so major planets in our solar system, but miss out on on a whole host of the most common types of planet in the universe? What makes us so special?
I like a lot of things about the cosmos (I’m particularly enamoured of its three convenient dimensions and perfectly-tuned fine-structure constant). But the thing I like most is that humans didn’t come up with it. The universe may not be packed wall to wall with Earths, but it’s definitely full of surprises.
Well, now I don’t know what to think.
Congratulations – you are now a scientist!