NASA's "New Worlds Observer" Will be Able to Spot Oceans, Continents and Clouds on Small Rocky Planets
NASA has committed $3 billion for a new space telescope powerful enough to discover planets like Earth and even signs of alien life. The New Worlds Observer will be able to identify planetary features like oceans, continents, polar caps and cloud banks and even detect biomarkers (image) like methane, oxygen and water if they exist.
Its "eye" to the cosmos will be a four-meter-wide mirror that will collect nearly three times as much light as the 2.4-meter mirror on the Hubble space telescope.
The NWO will feature a 50-yard wide, daisy-shaped plastic "sunshade" with petals made from black plastic like that used for rubbish bags. It will block the brilliant light from the distant stars, shielding their overpowering glare and allowing the telescope to observe any planets in orbit around them and zero in on Earth-like planets in other solar systems.
The thin plastic "starshade" would allow a telescope trailing thousands of miles behind it to image light from distant planets skimming by the giant petals without being swamped by light from the parent stars. Researchers could then identify planetary features like oceans, continents, polar caps and cloud banks and even detect biomarkers like methane, oxygen and water if they exist.
"We think this is a compelling concept, particularly because it can be built today with existing technology," said Webster Cash director of University of Colorado-Boulder's Center for Astrophysics and Space Astronomy. "We will be able to study Earth-like planets tens of trillions of miles away and chemically analyze their atmospheres for signs of life."
Scientists would launch the telescope and starshade together into an orbit roughly 1 million miles from Earth, then remotely unfurl the starshade and use small thrusters to move it into lines of sight of nearby stars thought to harbor planets, said Cash. The thrusters would be intermittently turned on to hold the starshade steady during the observations of the planets, which would appear as bright specks.
"Think of an outfielder holding up one hand to block out the sunlight as he tracks a fly ball," said Cash, . "We would use the starshade as a giant hand to suppress the light emanating from a central star by a factor of about 10 billion."
Last week, Nasa scientists revealed that as many as 60 per cent of nearby stars like the Sun could have terrestrial-type planets. And an international team used a technique called OGLE to discover a new solar system that they say most resembles our own.
The telescope and its 50-yard-wide starshade would launch into an orbit roughly 1 million miles from Earth. The parasol would then unfurl and be steered by thrusters into the lines of sight of nearby stars which are thought likely to have planets.
Professor Cash said: "This observatory can be built today with existing technology." He believes he could have the telescope ready for launch in 2017.
Posted by Casey Kazan.
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