Scientists now estimate that one in five sunlike stars have Earthlike planets in the habitable zone.
Scientists now estimate that one in five sunlike stars have Earthlike planets in the habitable zone.
This conclusion is entirely statistically based, and should be treated with some skepticism. Still, it seems reasonable, and I think it is likely to be a close approximation of the truth, when we finally begin to gather some real data.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Scientists now estimate that one in five sunlike stars have Earthlike planets in the habitable zone.
This conclusion is entirely statistically based, and should be treated with some skepticism. Still, it seems reasonable, and I think it is likely to be a close approximation of the truth, when we finally begin to gather some real data.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
1 in 5? I would take 1 in 100. That would still mean 10s of millions in our galaxy alone.
The real question is how many have molten iron cores like Earth.
Without that they have no way of creating a magnetic shield around the planet that protects it.
There is a higher chance of the planet having an atmosphere than a magnetic core but it needs both for higher forms of life to live there.