I think he just meant with liquid water, some type of atmosphere, and approximately earth sized. Given this, my guess is that they find one within the next three years. If he meant “habitable” to human beings without protection, i.e. oxygen atmosphere etc., then this is extremely unlikely (less than 2% chance) that they will find such a thing by 2020.
Is it possible to have liquid water without life? I remember reading that an oxygen atmosphere was quite impossible, but am not sure about liquid water.
There could be an oxygen atmosphere without life for a short period of a planet’s history (I’m not sure how long.) It wouldn’t be possible for it to remain permanently.
According to our evidence, Mars had liquid water for a very long period, but no one considers this to be proof that there was life there.
According to our evidence, Mars had liquid water for a very long period,
I went to check this—maybe liquid water is a short-term enough thing that its mere presence is still weak evidence for an active biosphere, but apparently one timeline puts liquid water as present in large quantities for >600 million years. Bleh.
We don’t. My prediction then is only almost certainly true if we define habitable as a planet in a sun’s habitable zone. However, I still think finding a habitable planet, per Unknowns’s definition, is likely to happen by 2020.
If Kepler does indeed find hundreds of planets in habitable zones, that should get the popular imagination going enough for the successor to Kepler to be very well funded. Kepler Mark II in the air by 2017?
I think I’d give better-than-even odds for either date, and would be shocked if no one else would. How are you defining “Earth-like” and “habitable”?
I think he just meant with liquid water, some type of atmosphere, and approximately earth sized. Given this, my guess is that they find one within the next three years. If he meant “habitable” to human beings without protection, i.e. oxygen atmosphere etc., then this is extremely unlikely (less than 2% chance) that they will find such a thing by 2020.
Is it possible to have liquid water without life? I remember reading that an oxygen atmosphere was quite impossible, but am not sure about liquid water.
There could be an oxygen atmosphere without life for a short period of a planet’s history (I’m not sure how long.) It wouldn’t be possible for it to remain permanently.
According to our evidence, Mars had liquid water for a very long period, but no one considers this to be proof that there was life there.
I went to check this—maybe liquid water is a short-term enough thing that its mere presence is still weak evidence for an active biosphere, but apparently one timeline puts liquid water as present in large quantities for >600 million years. Bleh.
Yes.
I’m not sure we have the technology to make that call even if such a planet does, in fact, lie within range of our telescopes.
We don’t. My prediction then is only almost certainly true if we define habitable as a planet in a sun’s habitable zone. However, I still think finding a habitable planet, per Unknowns’s definition, is likely to happen by 2020.
http://www.npr.org/templates/story/story.php?storyId=101493448
If Kepler does indeed find hundreds of planets in habitable zones, that should get the popular imagination going enough for the successor to Kepler to be very well funded. Kepler Mark II in the air by 2017?
At even odds I would take a loan to make the bet.