50 billion planets in our galaxy

[Chris]

WASHINGTON (AP) — Scientists have estimated the first cosmic census of planets in our galaxy and the numbers are astronomical: at least 50 billion planets in the Milky Way.

At least 500 million of those planets are in the not-too-hot, not-too-cold zone where life could exist. The numbers were extrapolated from the early results of NASA's planet-hunting Kepler telescope.

Kepler science chief William Borucki says scientists took the number of planets they found in the first year of searching a small part of the night sky and then made an estimate on how likely stars are to have planets. Kepler spots planets as they pass between Earth and the star it orbits.

So far Kepler has found 1,235 candidate planets, with 54 in the Goldilocks zone, where life could possibly exist. Kepler's main mission is not to examine individual worlds, but give astronomers a sense of how many planets, especially potentially habitable ones, there are likely to be in our galaxy. They would use the one-four-hundredth of the night sky that Kepler is looking at and extrapolate from there.

The Associated Press: Cosmic census finds crowd of planets in our galaxy

 

[waltky]

Granny says, "Dat's right - the gubmint gettin' ready to tell the truth dat dey really is lil' green men...

Study: Earth-Like Planets Closer Than Expected
February 06, 2013 - Astronomers say there could be as many as 4.5 billion Earth-like planets orbiting stars in the Milky Way galaxy, and the nearest of them could be practically next door, in cosmic terms.

Scientists at the Harvard-Smithsonian Center for Astrophysics, after analyzing data from NASA's Kepler space telescope, calculated that six percent of the galaxy's 75 billion red dwarf stars have potentially habitable, Earth-sized planets. Red dwarfs -- which are smaller, cooler and much dimmer than our own Sun - are the most common stars in the galaxy, so the closest Earth-like planet could be just 13 light years away, the astronomers conclude in their new study. "We thought we would have to search vast distances to find an Earth-like planet," said Harvard astronomer and lead author Courtney Dressing at a Cambridge, Massachusetts, news briefing. "Now we realize another Earth is probably in our own backyard, waiting to be spotted."

Working from Kepler's 158,000-star catalog, Dressing culled all the red dwarfs and profiled their sizes and temperatures, as well as the number of planet candidates in orbit around them. She narrowed this planet list down to those of just the right size, temperature and distance from their host star to harbor liquid water and, possibly, life as we know it. Dressing's analysis found just three planetary candidates that were both warm and approximately Earth-sized. Statistically, that meant that six percent of all red dwarf stars throughout the galaxy should have an Earth-like planet.

"We now know the rate of occurrence of habitable planets around the most common stars in our galaxy," co-author David Charbonneau, also with the Center for Astrophysics, told reporters. "That rate implies that it will be significantly easier to search for life beyond the solar system than we previously thought." Our sun is surrounded by a swarm of red dwarf stars. In fact, about 75 percent of the closest stars are red dwarfs. They are good places to look for Earth-like planets not only because they are so numerous. Their smaller size also makes it easier for astronomers to spot a relatively large Earth-size planet as it transits across the star's disk.

The Harvard astronomers say locating nearby, Earth-like worlds will require a dedicated small space telescope, or a large network of ground-based telescopes. And they are hopeful that follow-up studies with instruments like the soon-to-be-operational Giant Magellan Telescope in Chile and the James Webb Space Telescope -- due to be launched in 2018 - could eventually tell us whether any warm, transiting planets have an atmosphere and life-friendly chemistry. Since red dwarf stars last much longer than Sun-like stars, the astronomers say their analysis raises the possibility that life on one of their Earth-like planets would be much older and more evolved than life on Earth. The results of the study are published in The Astrophysical Journal.

Study: Earth-Like Planets Closer Than Expected

 

[waltky]

Granny wantin' to know how we s'posed to find out which o' dem space aliens is flingin' meteors at us?

Kepler Malfunction Imperils Search for Distant Earths
May 15, 2013 - NASA says its Kepler space telescope, which has been leading the search for Earth-like planets throughout the universe, has been crippled by the failure of one of the mechanical reaction wheels that helps keep it pointed.

The U.S space agency announced Wednesday that unless the reaction wheel's operation can be restored, or another way found to orient the spacecraft, Kepler's planet-hunting efforts will have come to a premature end. Kepler was launched in 2009 on a seven-year mission to determine how many stars beyond our solar system are likely to host Earth-like planets in habitable orbits. The space telescope has been carrying out a survey of hundreds of thousands of stars in one region of space looking for tell-tale blinks in starlight that signal the transit of an orbiting planet. So far, Kepler has identified 132 exoplanets and spotted 2,740 candidates.

This artist's rendering provided by NASA shows the Kepler space telescope.

NASA officials say they will continue trying to fix the faulty spacecraft, and will not give up on Kepler until the space telescope can no longer perform useful science. Kepler was launched with four reaction wheels, and needs at least three of the critical positioning devices to keep its telescopic instruments precisely aimed at distant stars. One failed last year, and the wheel that failed Wednesday began showing signs of abnormal friction several months ago.

NASA engineers tried shutting down the space telescope for two weeks, in the hope that lubricants might redistribute on the wheel and solve the problem. But the friction was still there when they resumed operations. Until now, the problem had not interfered with telescope operations.

Source

 

[Politico]

They are all guesses of course. But there's gotta be some out there. If we are the only intelligent form of life the universe is fucked.

 

[ScienceRocks]

Time to increase nasa's budget to 50 billion and put up a dozen keplers, JWT, ect.

Knowledge and the advancement of our species understanding is worth that much. Having bases and defending the entire world from its self isn't. That isn't worth more then 250 billion at most.

 

[PredFan]

Being in the habitable zone isn't the only criteria. It's much much more complicated than that. First we have to define what we're searching for. Are we searching for "life" or "sentient life". I believe that we will find extraterrestrial "life" in our own solar system.

Sentient life however, is a way more difficult thing to find. You need to be in the inhabitable zone, PLUS, the planet cannot be too big or too small, must be a solid planet and not a gaseous ball, it must have passed it's volcanically unstable phase, it cannot be bombarded with radiation, etc. etc.