100 MILLION worlds may hold alien life in our galaxy. Now NASA has detailed exactly how it expects to find the first inhabited planet other than our own within our lifetimes.
“Just imagine the moment, when we find potential signatures of life. Imagine the moment when the world wakes up and the human race realises that its long loneliness in time and space may be over — the possibility we’re no longer alone in the universe,” Matt Mountain, director and Webb telescope scientist at the Space Telescope Science Institute in Baltimore said this morning.
That moment, he believes, is likely to be within the next 20 years.
A meeting was held at NASA’s Washington headquarters this morning to detail international efforts aimed at finding life out there.
The presentation detailed NASA’s road map for the search for life in the universe, involving a series of current and future telescopes.
“Sometime in the near future, people will be able to point to a star and say, ‘that star has a planet like Earth’,” Sara Seager, professor of planetary science and physics at the Massachusetts Institute of Technology in Cambridge, Massachusetts, told the gathering of NASA and affiliated planet hunters.
The meeting comes after a group of international astronomers and astrobiologists published new research assessing the possibility of complex life on other worlds.
Their estimate — described as conservative — calculates 100 million worlds in our own galaxy are able to sustain complex alien life. That’s from among the 17 billion Earth-sized worlds believed to be spinning around the Milky Way’s 100 billion stars.
“I think in the next 20 years we will find out if we are not alone in the universe,” NASA Astronomer Kevin Hand said yesterday.
The planet hunt has been picking up pace in recent years. What started as ground-based radio observatories and telescopes has already moved to space-based facilities such as the Hubble, Kepler and Spitzer telescopes.
What they can tell is limited, but revealing: They can determine if a planet is the right distance from a start to hold liquid water.
This is the “Goldilocks Zone”, where conditions are “not to cold, not too hot — just right” for life as we know it.
So far, the few “best contenders” for life are believed to have conditions little better than that found on Jupiter’s moon, Europa
But NASA has now detailed a new generation of telescopes being built on the ground and being sent into orbit in the search for “Earth 2.0”.
Much of its hopes for finding evidence of life is being placed in the Transiting Exoplanet Surveying Satellite (TESS), due to be launched in 2017, the James Webb Space Telescope in 2018 and two further as-yet-unfunded projects scheduled for the next decade.
These telescopes will not only find and position a planet, they are hoped to provide clues as to their atmospheric make-up and greatly refine what we have already inferred.
In particular, they’ll be looking for water. But they’ll also be looking for other signs.
“Chemicals in our atmosphere like methane and oxygen would quickly combine meaning
something has to be replenishing them, so if we find these in another world’s atmosphere
we have a clue that something is creating it,” Australian astronomer Dr Alan Duffy, Research Fellow at the Swinburne University of Technology, said this morning. “This might not be life but it’s a first clue.”
The success of the planet-hunting program has produced phenomenal results in recent years.
Since its launch in 2009, the Kepler telescope shook up the astronomy community with its discovery of more than 5000 potential exoplanets, of which more than 1700 have been confirmed.
“This technology we are using to explore exoplanets is real,” said John Grunsfeld, astronaut and associate administrator for NASA’s Science Mission Directorate in Washington. “The James Webb Space Telescope and the next advances are happening now. These are not dreams — this is what we do at NASA.”
This decade has seen the discovery of more and more super Earths, which are rocky planets that are larger and heftier than Earth. Finding smaller planets, the Earth twins, is a tougher challenge
Kepler was the first to pinpoint planets known to be within the “Goldilocks Zone”, and indicates most worlds at that range are generally less than three-times the size of Earth.
“What we didn’t know five years ago is that perhaps 10 to 20 per cent of stars around us have Earth-size planets in the habitable zone,” says Matt Mountain, director and Webb telescope scientist at the Space Telescope Science Institute in Baltimore. “It’s within our grasp to pull off a discovery that will change the world forever.”