Billions Of Planets In The Milky Way!

[Damo636]

'Tens of billions' of planets in habitable zones - Yahoo! News UK

[richbyers]

i am a strong believer in life out side of earth- i am planning on starting an ou course in november that centers around the search for life so it should be interesting

personally i look forward to what the next half decade or so will bring for astronomy

[Capricorn]

This was on the BBC site yesterday and it was a little less definite.

BBC News - Super-Earths 'in the billions'

There could be many billions of planets

Could be not are.

The estimate for the number of "super-Earths" is based on detections already made and then extrapolated to include the Milky Way's population of so-called red dwarf stars.

An estimate and not actually seen but an extrapolation. According to the BBC artical they carefully chose 102 stars. Careful choosing suggests a bias one way or another, otherwise you select at random N red dwarfs for a more representative result.

Harps employs an indirect method of detection that infers the existence of orbiting planets

I know it uses star "wobble" and so Red/Blue shift, but the way this is presented comes over as a little less then certainty.

I note that the Yahoo one is more specific in saying billions and little doubt. Interesting and subtle change in the report.

Not sure if Yahoo said:

But red dwarfs are known to be prone to stellar eruptions, or flares, which could bathe a nearby planet in X-rays or ultraviolet radiation, and that might make life there less likely.