reported in search
for extra-terrestrial life
William Borucki, Kepler Science Principal Investigator at NASA/Ames Research Laboratory, led the news briefing.
SCIENCE FICTION TOOK a giant step towards becoming scientific fact at a four-day conference at NASA’s Ames Research Center in Northern California, which ended Thursday.
The research findings presented – extrapolated into the future – could have profound effects on the human condition as it becomes increasingly likely that we are not the only life forms in the galaxy.
Scientists in a number of disciplines – including astrophysics and asteroseismology (the music of the stars) – presented a growing body of evidence pointing to the inevitability of finding another planet similar to earth that is capable of supporting life.
THE RESEARCH IS based on observations from the Kepler Telescope launched in March 2009 and managed in part by the Jet Propulsion Laboratory, just three miles from my house.
At a fascinating one-hour press briefing summarizing the findings Michele Johnson of NASA Ames Public Affairs introduced the four principals who presented their findings in easy-to-understand vernacular, sprinkled with scientific terminology but all pointing to the same conclusion.
The hour-long media briefing began the Second Kepler Science Conference in Mountain View, Calif.
The briefing includes statements from William Borucki, Kepler Science Principal Investigator at Ames; Jason Rowe, research scientist at SETI Institute in Mountain View, Calif.; Erik Petigura, a doctoral candidate at UC Berkeley; and William Chaplin, professor of astrophysics at the University of Birmingham, UK.
“At this meeting we are celebrating the opening of a new era in astronomy beginning the exploration of our galaxy,” Borucki said.
“We’ve already learned that about 70 percent or more of the stars we’re examining show evidence of planets. Many of them show planetary systems.”
Borucki explained that analysis of the data collected by Kepler is determining the frequency of these planets and it will be followed by another mission which will be determining which of the nearby stars have planets ….
“In the planets we have already found [there is] a bewildering variety,” he said. “We have planets which are mini-Neptunes (gaseous), we have planets which are almost entirely water. We have some planets which are bigger than our biggest planet Jupiter, and some smaller than the planet Mercury.”
But, he pointed out, Kepler has only searched one-four-hundredth of the sky. “Imagine what these other missions will find if we continue that exploration,” he said.
The SETI Institute web site with the news announced at the Kepler Science Conference. Click image to enlarge.
It is not difficult to imagine. And as one listens to the other presenters, it becomes almost inevitable.
According to Borucki, Kepler has produced information about 170,000 stars with about 3,500 planetary candidates.
Up next was scientist Jason Rowe of the SETI Institute who described the quantum leap in data analysis over the past nine months.
“Back in January we had 2,740 [planet] candidates with two years of data,” Rowe said. “Now with three years of data … that brings our grand total up to 3,538. That means there are 833 new candidates that we are going to announce today.”
Most of the new candidates are quite small. The majority of them are earth size, he said, therefore more likely to support life.
“In our three-year data set, we are getting very good at finding small planets and planets with long orbital periods,” Rowe added.
“This is exactly what we need to do to march towards finding earth-sun analogues.”
He noted that in January, with only two years of data analyzed, there were 351 earth-sized planets. “Now with our new totals, we can see the dramatic increase is all towards the smaller end – we now have 647 earth-sized planets. … that is a 78 percent increase,” Rowe said.
A graphic presented by Erik Petigura illustrating the “habitable zone” in which he is searching for earth-like planets.
But this has to be further qualified. Not all of them are within what scientists have called the “habitable zone” – also called the ‘goldilocks zone’, where the required conditions exist that might support life.
How many of these planets are in the habitable zone of their host star? “We now have 104 candidates that are in the habitable zone of their host star,” Rowe reported.
He noted that the analysis is still not complete. There is sill another year’s worth of data to be analyzed.
“So it will be very exciting to see what the future holds,” Rowe said. “… It is remarkable that there has been a 78 percent increase in the number of earth-sized planets.”
ALSO IN THE news briefing was U.C. Berkeley doctoral candidate Erik Petigura, who’s research was reported Tuesday in a front page story in The New York Times headlined Far-Off Planets Like the Earth Dot the Galaxy.
“We began by asking a simple question: what fraction of stars have a planet similar to earth?” Petigura said at the briefing.
A graphic depicting “the music of stars” being studied by Bill Chaplin at the University of Birmingham in the UK.
“Today I am happy to report that 22 percent of sun-like stars harbor a planet in the habitable zone… that is a planet that is between one and two times the size of the earth bathed in a similar amount of stellar intensity as the earth is, to a factor of four.”
Petigura explained he has spent the last three years writing, debugging and optimizing a software package that was used to search for these planets.
“At the end of the day … we find 603 planet candidates among these 40,000 stars,” he said.
“Ten planets we identify as small – one to two times the size of earth – and in the habitable zone: they receive the same amount of light intensity as the earth does to a factor of four.”
Overall, he added, “Twenty-two percent of sun-like stars harbor a habitable planet…in other words, one out of five sun-like stars harbors an earth size planet.”
One out of five is huge. And the work has only just begun.
The Kepler telescope, however, has been disabled by a mechanical malfunction, but there is still one more year of its data to analyze.
Remember, as Borucki said, only 1/400th of the galaxy has been examined. Extrapolate Petigura’s results by 400 and the likelihood of finding an earth-like planet in the habitable zone increases into the realm of probability, beyond just a possibility.
It is simply remarkable.
In the annals of human history, finding another earth-like planet capable of supporting life will rank right at or above Neil Armstrong’s stroll on the moon in 1969.
Finding hundreds or perhaps thousands of them exponentially increases the likelihood that one or more does indeed support life.
At that point, we will have to reassess the human condition. We will no longer be alone.
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