Planets … everywhere

Artist's impression of Earth-like planets elsewhere in the Milky Way galaxy (ESO/L Calcada)

It’s proving difficult to keep up with the many discoveries of planets outside the Milky Way. But from what we learn about our galaxy, the solar system seems a run-of-the-mill place.

The latest result of observations with ground-based telescopes operated by the European Southern Observatory is a haul of 32 planets ranging in size from five times the mass of the Earth, to around 10 times that of the solar system’s largest body, Jupiter. It has got to the point where astronomers can confidently declare that low-mass extra-solar planets are commonplace. This is a remarkable leap in understanding, the significance of which should not be underestimated.

“From [our] results, we know now that at least 40% of solar-type stars have low-mass planets. This is really important because it means that low-mass planets are everywhere, basically,” said Geneva University astronomer Stéphane Udry to the BBC.

During a press conference held earlier today, Udry was even more direct:

“I’m pretty confident that there are Earth-like planets everywhere. Nature doesn’t like a vacuum. If there is space to put a planet there, there will be a planet there.”

If true, it seems almost inevitable that there is life out there inhabiting these myriad worlds, and most likely at many stages of development. That we have yet to discover extraterrestrial life says no more than that we have so far not looked in the right place, in the right way.

Give it time. The evidence won’t come in the form of grainy pictures of high-browed humanoids with silvery skin and obsidian eyes, but most likely tell-tale chemical signatures from observations of planetary atmospheres.

That should be enough to convince the most hard-hearted little Earthlander that we are not alone in the universe. It will be the next great humanistic revelation.