Download NASA discovers Earth`s bigger, older cousin, Kepler 452b

http://www.news.com.au/technology/science/nasa-discovers-earths-bigger-older-cousinkepler-452b/story-fnjwlcze-1227454755492
NASA discovers Earth’s bigger, older cousin,
Kepler 452b

JULY 24, 2015 10:51AM
This artist’s concept depicts one possible appearance of the planet Kepler-452b, the first near-Earth-size world
to be found in the habitable zone of star that is similar to our sun. Picture: NASA Ames/JPL-Caltech/T.
Pyle Source: Supplied

NASA finds closest twin to Earth 2.0: Kepler-452b

Orbits star every 385 days

60 per cent larger radius than Earth

Likely mass 5-times that of Earth

Located 1,400 light years away
“ARE we alone in the universe?
“We’re taking one small step in answering that question today.”
And with that, astronomers hunting for another Earth announced they have found what may
be the closest match yet, a potentially rocky planet circling its star at the same distance as the
Earth orbits the Sun, NASA said overnight.
“Until about 20-years ago, we didn’t know the answer to that. Now we have a definitive
answer.
“Today we’re announcing the discovery of an exoplanet that as far as we can tell, is a pretty
close cousin to the Earth and our sun.
NASA says new Earth-like planet discovered
“This is about the closest twin to Earth 2.0 that we’ve found so far, and I really emphasise so
far.”
Not only is this planet squarely in the Goldilocks zone — where life could exist because it is
neither too hot nor too cold to support liquid water — its star looks like an older cousin of our
Sun, the US space agency said.
Artist impression of the surface of Kepler 452b created by the SETI institute, who have been working in
conjunction with NASA. Credit: SETI Institute/Danielle Futselaar Source: Supplied
How the planets stack up in comparison to Kepler-452b. Picture: NASA Source: Supplied
— WHAT WE KNOW SO FAR —
Known as Kepler-452b, the planet was detected by the US space agency’s Kepler Space
Telescope, which has been hunting for other worlds like ours since 2009.
“Kepler-452b is orbiting a close cousin of our Sun, but one that is 1.5 billion years older,”
NASA said in a statement.
Kepler-452b orbits a parent star, belonging to the same class as the sun, it’s just 4 per cent
bigger and 10 per cent brighter. It takes 385 days to orbit the star.
Its radius is 60 per cent larger than Earth with a likely mass five times that of our own.
“You and I would weigh twice as much as we do now on the planet”, said John Grunsfeld,
associate administrator for NASA’s Science Mission Directorate in Washington.
“We’d also expect the atmosphere to be thicker and with more cloud cover, with very active
volcanoes.”
Kepler-452b’s orbit is nearly the same size of Earth, using ten per cent more energy.
According to NASA, Earth will follow in Kepler’s footsteps and will receive the same
amount of energy in 1.5 billion years.
The planet, located in the “habitable zone” of the universe, lies 1,400 light years away.
“We know little about the atmosphere about this planet, it certainly has an atmosphere but
details of its composition are totally unknown to us,” said Jon Jenkins, Kepler data analysis
lead at NASA’s Ames Research Center in Moffett Field, California.
The sweep of NASA Kepler mission’s search for small, habitable planets in the last six years. Picture:
NASA Source:Supplied
— IS THERE EVIDENCE OF LIFE ON KEPLER-452B? —
Jenkins was wary about confirming or denying this, adding Kepler’s job description was to
“count the number of small planets in our near the habitable zones of sun-like stars” instead
of touching down on the planet and searching for alien life.
“The exciting thing is we’ve found so many planetary systems that are unlike our solar
system. Signs of life require advanced technology and instruments in space, and so what
Kepler is doing is telling us there are world’s out there that we can go forward and pursue
following them up.”
There are 4,696 planet candidates now known with the release of the seventh Kepler planet candidate catalogue
— an increase of 521 since the release of the previous catalogue in Jan. 2015. The blue dots show planet
candidates from previous catalogues, while the yellow dots show new candidates from the seventh catalogue.
New planet candidates continue to be found at all periods and sizes due to continued improvement in the
detection techniques. Picture: NASA Ames/W. Stenzel Source: Supplied
— COULD HUMANS LIVE ON THE PLANET? “This is humankind’s first step,” said Kepler research scientist Jeff Coughlin.
“It’s a long-term goal but a very exciting one.
“You and I probably won’t be travelling to these planets — but our children’s children could
be. This gives us something to aim for.”
“One generation from now we might be able to get there. It gives humankind something to
shoot for.”
Coughlin went on to say that Mars was the next closest habitable planet in our solar system.
Today Kepler-452b is receiving 10 per cent more energy from its parent star than the Earth is from the Sun.
Kepler-452b has spent six billion years in the habitable zone of its star; longer than Earth. Picture: NASA
Ames/J. Jenkins Source:Supplied
— IS THERE EVIDENCE OF LIFE IN THE UNIVERSE? “We’re listening in to see if anyone is broadcasting (from another planet), using radio
waves,” said Jeff Coughlin, Kepler research scientist at SETI Institute in Mountain View,
California.
“That’s a hard question to answer, we’re taking steps about as aggressively as technology
will permit.
“We really don’t know what (a civilisation) would use, if there is something better than radio.
“We’ll stick with what we do know and keep listening. If down the road we find something
better we’ll use that.”
The team detailed the difficulties in reaching such universes, and the hurdles in finding
extraterrestrial life.
“Before we get pictures of the sorts we just got from Pluto, where we fly-by a distant
exoplanet and beam back to Earth the images, the speed at which the aircraft can get there,
the speed of light, is many decades.
“First we have to discover the planets, but we can learn a lot from surveillance.
“If we had a sufficiently large telescope with current technology we could make the first
primitive maps of an Earth-like planet.
Whether they have oceans, clouds, perhaps even seasons and start characterising what those
planets are like.
“Whether we can discover life is a tricky question, would we recognise those signs of life?
“Those kinds of telescopes might be able to do that as well.”
Twelve Exoplanet discoveries from Kepler that are less than twice the size of Earth and reside in the habitable
zone of their host star. These are arranged by size from left to right, and by the type of star they orbit, from the
M stars that are significantly cooler and smaller than the sun, to the K stars that are somewhat cooler and smaller
than the sun, to the G stars that include the sun. Picture: NASA/JPL-CalTech/R. Hurt Source: Supplied
— GLIMPSE INTO APOCALYPTIC FUTURE —
The planet, which is 1,400 light-years away, could offer a glimpse into the Earth’s
apocalyptic future, scientists said.
Its star is four per cent more massive than the Sun and 10 per cent brighter. If the planet is
rocky, and scientists believe that it has a better than even chance of being just that, then it
could be in the midst of a fearful scenario, as the heat from its dying star evaporates Kepler452b’s lakes and oceans.
“If Kepler-452b is indeed a rocky planet, its location vis-a-vis its star could mean that it is
just entering a runaway greenhouse phase of its climate history,” said Doug Caldwell, a
Search for Extraterrestrial Intelligence (SETI) Institute scientist working on the Kepler
mission.
“The increasing energy from its ageing sun might be heating the surface and evaporating any
oceans. The water vapour would be lost from the planet forever,” he added.
“Kepler-452b could be experiencing now what the Earth will undergo more than a billion
years from now, as the Sun ages and grows brighter.”
Kepler - Window into time
- PLANETARY CATALOGUE —
The Kepler mission launched in 2009 to search for exoplanets, which are planets outside our
solar system, particularly those about the size of Earth or smaller.
“Today, and thousands of discoveries later, astronomers are on the cusp of finding something
people have dreamt about for thousands of years — another Earth,” NASA said in a
statement.
On Thursday, NASA released the latest catalogue of exoplanet candidates, adding more than
500 new possible planets to the 4,175 already found by the space-based telescope.
“This catalogue contains our first analysis of all Kepler data, as well as an automated
assessment of these results,” said SETI Institute scientist Jeffrey Coughlin.
This size and scale of the Kepler-452 system compared alongside the Kepler-186 system and the solar system.
The size of the orbit of Kepler-452b is nearly the same as that of the Earth at 1.05 AU. Kepler-452b orbits its
star once every 385 days. Picture: NASA Source: Supplied
The new catalogue includes 12 candidates that are less than twice the diameter of Earth and
which are orbiting in the habitable zones of their stars.
Of those 12 new candidates, Kepler-452b “is the first to be confirmed as a planet,” NASA
said.
Kepler identifies possible planets by watching for dips in the brightness of stars, which could
be caused by a planet passing between the star and the telescope.
Other scientific tools are needed to judge whether the planet is gassy or rocky. The Kepler
mission has cost NASA about $600 million, and the US space agency said in 2013 that two of
its orientation wheels had lost function, leaving the space telescope beyond repair.
But scientists have years to pore over the data it has returned in order to narrow the search for
Earth-like worlds.
- Additional reporting by AFP
Picture: NASA Source: Supplied