NASA scientists believe they could find a 'second Earth' within the next generation and then look at how to travel there.
.jpg)
NASA astronomers believe there are one billion Earth-like planets in the Milky Way alone
Bill Borucki - lead investigator for the Kepler mission, a space-based telescope that orbits our Sun and looks at over 100 thousand stars simultaneously - said: "We have learned most stars have planets, that Earth-sized planets are common, and a good fraction are in the habitable zone of their star.
"And when you put the numbers together: 100 billion stars, 10 per cent with Earth-sized planets, 10 per cent stars like the sun, that’s a billion Earth-sized planets in the habitable zone of stars like the Sun.
"Let me repeat that last bit. There may be a billion Earth-sized planets in the habitable zone of a Sun-like star.
"Thirty years ago, astronomers weren’t sure of any. And that, of course, is just within our galaxy.
“There are billions of stars in our galaxy alone, billions of galaxies out there.
Artist impression of planets orbiting stars in the Milky Way
"The numbers are, fortunately, very much in our favour.”
Mr Borucki spoke of his hopes at the opening ceremony of the Carl Sagan Institute at Cornell University, New York State, which was founded solely to explore the possibility of life on the cosmic horizon.
Never before has there been such a buzz about the prospect of soon finding other life forms.
Natalie Batalha, an astronomer at NASA’s Ames research centre told website Gizmodo.com: "Finding evidence of life beyond Earth is not a pipe dream. It's something we can accomplish—maybe not within my lifetime, maybe within my daughter’s life.”
The Kepler mission has so far discovered over 4,100 possible planetary candidates and 1,000 confirmed planets, and is only looking at a contained area of space.
Scattered among them, a handful of so-called “Goldilocks” planets — those not-too-hot and not-too-cold for life - have been discovered to be orbiting stars like the Sun .
Miss Batalha said: "These planets are relatively common, and using statistics, we know they’re likely to be nearby.”
Graph showing the huge surge in discovery of so-called exo planets that could support life last year
Building on Kepler's work is the Transit Exoplanet Survey Satellite (TESS), which launches in two years.
It will scan the entire sky, monitoring more than half a million stars in Earth's closest cosmic vicinity.
Astronomer Lisa Kaltenegger, the brainchild behind the institute, said: "TESS will be like Kepler, just doing transit, but instead of staring at one particular part of sky, it’ll scan the entire sky, focusing on our nearest neighbours. It’ll allow us to pick a lot of promising targets that are much closer than the Kepler planets.”
The James Webb Space Telescope, a 6.5 metre-long solar-powered observatory, will takeover from the Hubble Telescope in 2018, and will scan the cosmos for more likely Earth-like planets to explore.
From around 2025, the Wide Field Infrared Survey Telescope (WFIRST), using a technique called micro-lensing, will detect smaller than Earth-sized planets orbiting at the same distance between Earth and the Sun when a "life finder" mission among various space agencies begins.
Miss Batalha added. “WFIRST is going to get the statistics of planets orbiting at an Earth orbit or outward.
"So, over time, we’re going to build up this comprehensive picture of what exoplanets are out there. Between now and the life finder, we’re not going to find nearby Earths in great numbers.
“But as long as we’re well positioned by 2025 to start putting money into a life finder, then I think we’ll have a hope of really making headway in three decades.”
At the Carl Sagan Institute's opening ceremony the question was asked of what will happen once a 'second Earth' is found.
How many of these stars in the Milky Way seen here from Earth could have planets orbiting them?
Cornell astronomer Steve Squyres, the lead investigator on the Mars Exploration Rover, said: "If somebody finds a real Earth-like planet within a few light years, my reaction is, lets start building a spacecraft.”
Didier Queloz, an exoplanet researcher at the University of Cambridge, added: “It took the human species ten thousand years to spread across the Earth. When I came here, it took me eight hours by plane to cross the Atlantic ocean.
"Maybe we need another hundred, or a thousand years, but it doesn’t seem so crazy to think we’ll be sending probes to these nearby planets. There is no fundamental limitation but the time.”
