Goldilocks planet found - Kepler-22b

The space chatter this week has been all about Kepler-22b - or Earth 2.0 as the general media quickly badged it.

Scientists analysing data from the Kepler Space Telescope have finally identified the first planet that is a) near-Earth in size - just 2.4 times the size of out planet, b) circling a star very similar to our own and c) about the right distance out from the star and not on too eccentric an orbit - of 289 days - so that the planetary temperatures are not too hot or cold (juuust right, as it were - a little below zero Celsius) for liquid water to exist - a key requirement for life - as we know it anyway. All of these 'ingredients" mean Kepler-22b is a good candidate for similar conditions to Earth's for life forming.

America's CBS News interviewed Neil Tyson on the topic. (Sorry iGadget users - it's Flash.)



Kepler is unlike Hubble. Kepler's focus is a quite small section of the sky, where it can focus on detecting changes in the light received from stars. Dips in the light can indicate planets passing in front of a star and blocking some of the light from it that reaches us. Wobbles sideways in a star could indicate the star is being pulled around as a planet orbits it - like how you have to lean back when swinging a child around.

As NASA advise, the number of planet candidates identified by Kepler now totals 2326. Of these, 207 are approximately Earth-size, 680 are super Earth-size, 1181 are Neptune-size, 203 are Jupiter-size and 55 are larger than Jupiter. And there are currently 48 'candidate' planets - not entirely confirmed yet - in their stars' Goldilocks zones. So expect more similar announcements. And expect a rapid waning in media interest as they come in, compared to this week's frenzy.

Now back to those CBS newsreaders - sheesh!

"Don't pack your bags yet. If you travelled at the speed of light, it would still take you 600 years to get there."

Um...no it wouldn't.

Point 1: you couldn't travel at the speed of light. But you could go close (but not with any technology we have as yet).

Point 2: the closer you go to the speed of light, the slower your own clock goes. The faster you go - the slower time passes. It's Einstein. Depending on your speed - and the time it took you to accelerate up to that speed and then decelerate as you got to your destination - it could take you just a few weeks of your timescale. Everyone you know back at home would be looong gone, but man you're travelling the galaxy - who cares about them?