Galaxy is stuffed with habitable worlds –and probably Aliens

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PostTue Nov 05, 2013 8:29 pm » by Constabul


Fresh data from the Kepler space telescope shows at least a fifth of stars surveyed have Earth-like planets in a "Goldilocks" orbit – a habitable sweet spot that's not too hot or too cold for liquid water – and that's just the stars we can see.
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Of the 150,000 stars in our Milky Way galaxy snapped by the NASA probe in the past three years, more than 3,000 planets have been identified. Scientists then focused on the stars similar to our Sun and tried to find planets between one and two times the size of Earth in those stars' Goldilocks orbital zones.

Their findings suggest that 22 per cent of those stars had planets about the size of Earth that could harbor liquid water – a basic building block for life as we know it. The team said the actual total could be much higher given the difficulty involved in finding them. Kepler relies on seeing planets pass directly in front of the target star on the same orbital plane as the telescope.
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"What this means is, when you look up at the thousands of stars in the night sky, the nearest Sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing," said UC Berkeley graduate student Erik Petigura, who led the analysis of the Kepler data.

The team looked at 42,000 stars that are similar to Sol and found 603 planets orbiting them at various distances. Of these ten were Earth-sized and distant enough from their stars to harbor liquids suitable for creating life.

Geoffrey Marcy, a professor of astronomy at Berkeley, extrapolated the findings across the open void of space, adding: "With tens of billions of Earth-like planets in each galaxy, our entire universe must contain billions of billions of Earth-like planets."
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However, that's just planets that can support life – there's no guarantee that they actually do or that they could support human existence. Finding that out is going to be a problem for the next generation, according to Natalie Batalha, Kepler mission scientist at NASA Ames Research Center.

She explained that there isn't any existing hardware, either on Earth or in orbit, that can answer the question of whether these smaller planets are habitable, but both the Hubble and Spitzer telescopes have been able to analyze the composition of the larger gas giants found in outer space.

"Is there hardware capable of detecting the atmosphere and its constituents of an Earth-like planet? The answer is no," she told El Reg. "But there are plans on the books to do exactly that and within the next 50 years we're going to see the characterization of their atmospheres.

"Beyond 50 years, the long-term object is to image the surfaces of these planets with a resolution that could detect land features and the light that reflects off them, to take spectrums of that light to really understand what's on the surface of the planet and looking for markers of life."

http://www.theregister.co.uk/2013/11/04 ... habitable/
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PostTue Nov 05, 2013 9:05 pm » by Noentry


The tipping point is close.
We may yet live to see ET on the white house lawn.

They gonna need to look at the numbers again.
It would seem the universe has the capacity for many other civilizations.
More then we could of ever dreamed off.


Fra­nk D­rake had to account for all of these variables in developing a formula to quantify the odds of finding extraterrestrial life. His first task was deciding what he wanted to calculate. First, he limited his thinking to extraterrestrials in our home galaxy -- and only those that might be capable of interstellar communication. Then he inserted a mathematical factor to account for all of the conditions required to enable such civilizations to evolve. The result is the following formula:

N = RfpneflfifcL

In this equation, N is the number of detectable civilizations in our galaxy. The other variables are described below:

R is the rate of star formation in the galaxy
fp is the fraction of stars that form planets
ne is the number of planets hospitable to life (i.e., Earth-like planets)
fl is the fraction of these planets on which life actually emerges
fi is the fraction of these planets on which intelligent life arises
fc is the fraction of these planets with intelligent beings capable of interstellar communication
L is the length of time such a civilization remains detectable

The only variable known with any degree of certainty is the rate of stellar formation, R. In the Milky Way, a typical spiral galaxy, new stars form at a rate of roughly four per year [source: Cain]. The variable astronomers feel most uncertain about is L, the length of time a civilization remains detectable. A variety of estimates have been used for L, ranging from 10 years to 10 million years.

Astronomers can make educated guesses about the rest of the variables. For example, of the nine planets in our solar system, only four are what astronomers call terrestrial planets -- those that have a solid surface. Of those terrestrial planets, only Earth supports life. If we take our solar system as representative, then we might argue that ne equals 1/4 or 0.25. Similar guesses have been made about the other variables and, interestingly, they all end up having very similar values, usually in a range between 0.1 and 1.0. So, a typical calculation might look like this:

N = 4 x 0.5 x 0.25 x 0.2 x 0.2 x 0.2 x 3,000,000

which gives us a value of 12,000 civilizations in our galaxy.

Drake's original calculations were very close to this value for N. When he ran the numbers, he predicted that there might be 10,000 detectable civilizations in the Milky Way [source: Garber]. Carl Sagan, a leader in the SETI movement until he passed away in 1996, was even more generous when he suggested that 1 million civilizations might exist in the galaxy.

http://science.howstuffworks.com/space/ ... -odds1.htm
"The third-rate mind is only happy when it is thinking with the majority.
The second-rate mind is only happy when it is thinking with the minority.
The first-rate mind is only happy when it is thinking."
A. A. Milne

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PostWed Nov 06, 2013 12:20 am » by Ufosarus


great post :flop:
without a douth theres 100,0000 of stars out there to support life,and whos not
to say we might be the most intelligent of them all, now that would be scarey :o



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