Kepler-22b: NASA confirms 'super-Earth' that could hold life

WASHINGTON: In another step toward finding Earth-like planets that may hold life, NASA said on Monday the Kepler space telescope has confirmed its first-ever planet in a habitable zone outside our solar system.

French astronomers earlier this year confirmed the first rocky exoplanet to meet key requirements for sustaining life. But Kepler-22b, initially glimpsed in 2009, is the first the US space agency has been able to confirm.

Confirmation means that astronomers have seen it crossing in front of its star three times. But it doesn't mean that astronomers know whether life actually exists there, simply that the conditions are right.

Such planets have the right distance from their star to support water, plus a suitable temperature and atmosphere to support life.

"We have now got good planet confirmation with Kepler-22b," said Bill Borucki, Kepler principal investigator at NASA Ames Research Center.

"We are certain that it is in the habitable zone and if it has a surface, it ought to have a nice temperature," he told reporters.

Spinning around its star some 600 light years away, Kepler-22b is 2.4 times the size of the Earth, putting it in class known as "super-Earths," and orbits its Sun-like star every 290 days.

Its near-surface temperature is presumed to be about 72 degrees Fahrenheit (22 Celsius). Scientists do not know, however, whether the planet is rocky, gaseous or liquid.

The planet's first "transit," or star crossover, was captured shortly after NASA launched its Kepler spacecraft in March 2009.

NASA also announced that Kepler has uncovered 1,094 more potential planets, twice the number it previously had been tracking, according to research being presented at a conference in California this week.

Kepler is NASA's first mission in search of Earth-like planets orbiting suns similar to ours, and cost the US space agency about $600 million.

It is equipped with the largest camera ever sent into space -- a 95-megapixel array of charge-coupled devices -- and is expected to continue sending information back to Earth until at least November 2012.

Kepler is searching for planets as small as Earth, including those orbiting stars in a warm, habitable zone where liquid water could exist on the surface of the planet.

The latest confirmed exoplanet that could support life brings to three the total number confirmed by global astronomers.

In addition to French astronomers' confirmed finding of Gliese 581d in May, Swiss astronomers reported in August that another planet, HD 85512 b, about 36 light years away seemed to be in the habitable zone of its star.

However, those two planets are "orbiting stars smaller and cooler than our Sun," NASA said in a statement, noting that Kepler-22b "is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our Sun."

"The Europeans have also been very active, actively working on confirming our candidates," said Natalie Batalha, Kepler deputy science team lead at San Jose State University.

"They have already confirmed two that are published and they have got another batch that are on the preprint servers so those will be, I'm sure, in the published literature soon," she added.

"So we are just thrilled about this. We need all telescopes observing these candidates so we can confirm as many as possible."

A total of 48 exoplanets and exomoons are potential habitable candidates, among a total of 2,326 possibilities that Kepler has identified so far.

How NASA Would Send Humans on Mars

Copy paste from: http://www.space.com/businesstechnology/090722-tw-mars-mission.html

By Charles Q. Choi Special to SPACE.com posted: 22 July 2009 09:18 am ET

As the 40^th-anniversary celebrations of the moon landing end, a human voyage to Mars remains a holy grail for NASA.

"We're still looking at human exploration of Mars as one of the goals of the future at the top level," said NASA researcher Bret Drake with Lunar and Mars Integration at Johnson Space Center in Houston. "Having a human actually set foot on another planet would be one of the greatest adventures possible, one of the greatest monuments to history."

A crewed mission to the red planet is a daunting challenge that lies at the edge of current technological capabilities and possibly beyond. Still, NASA keeps a strategy to go there and constantly keeps up to date with new ideas.

"Mars is one of those targets of fascination that has been around a long time," Drake said.

How to get there

A voyage to Mars would take a crew about 180 days. So far NASA is exploring two options for propulsion there — a nuclear thermal rocket and a chemical engine.

A nuclear thermal rocket, based off designs from the '60s and '70s, would use a nuclear reactor to super-heat a gas and blast it out the nozzle to generate thrust. "It's a very high-performance vehicle, and we think it's very safe, not radioactive at launch, but it is a nuclear system," Drake said. "The idea for the chemical engine is similar to that used on the space shuttle, liquid oxygen and liquid hydrogen. It's a fairly well-known technology, but it's not as efficient as nuclear thermal."

To reach the Martian surface, NASA envisions an aerodynamic lander that flies down with thrusters to help it descend. The ascent vehicle that takes the crew back into space for the six-month trip home will likely rely on a combination of methane and liquid oxygen. "Oxygen is present in the Martian atmosphere in the carbon dioxide, so you can use resources on Mars to make it," Drake said.

Before the crew even gets to Mars, the plan is to send as much cargo there ahead of time as possible.

"That way we can know it's operating right before we ever commit the crew," Drake said. "A Mars mission is not like a lunar mission where you can come home at any time — once they're committed, a crew is out there for years."

By current NASA estimates, a crewed mission to Mars needs to lift about twice the mass of the International Space Station into space — roughly 1.76 million lbs. (800 metric tons) of technology. To launch the equipment, NASA plans on using the Ares V rocket, designed to be the most powerful rocket ever built and capable of carrying about 414,000 lbs. (188 metric tons) to low Earth orbit at one time.

"We're going to try to minimize the amount of assembly needed," Drake said. "The heavy lift capacity we'll have with the Ares V will allow for simple automatic rendezvous in orbit and docking of components."

The crew would ride up in one of the upcoming Ares I rockets before starting the voyage to Mars.

"Having humans in place could bring a wealth of experience and training and the ability to put into context what they see and to make real-time decisions, all things difficult to do with robots," Drake said.

The very habitat the crew stays at on the Martian surface would be sent ahead of time. "You can also do things like produce and store oxygen from resources at Mars beforehand for the crew and the ascent vehicle. You could generate water as well."

Big crew, long stay

NASA envisions a crew of six astronauts for a Mars mission. "That's about what's required for the skills needed — a commander, scientist, engineer, medical officer, things like that, as well as cross-training," Drake said. "They'll need expertise in a wide range of disciplines."

Currently NASA envisions a long stay for a crew at Mars, about 500 days.

"Crew autonomy is vital, because there's an up to 40 minute time delay in communication between Earth and the crew because of the distance," Drake said. "And the crew doesn't have a capability for re-supply — they'll just have what they send ahead or what they bring with them — so when things fail, they'll have to be able to repair them. They must be self-sufficient."

To survive the voyage, air and water need to be completely recycled regularly.

"We're learning a lot on the International Space Station right now on air revitalization and water recovery," Drake said. "What's nice about Mars is that there's carbon dioxide in the atmosphere, so that can help get us oxygen and water for the crew. In terms of food, we're looking at smaller systems, 'salad machines,' to grow food for the crew. Fresh food is not only good for nutrition, but good for the mind as well. A fresh tomato can really boost psychology."

Mental and physical challenges

The long hardship of roughly two-and-a-half years in space with only a few people in a potentially lethal environment will undoubtedly challenge the psyches of Mars explorers.

"The Russians are conducting a test right now that hopefully will shed light on the behavioral sciences aspect of a Mars mission," Drake said. "Looking at other remote exploration endeavors is helpful as well — Antarctica, or submarines — all that feeds into the human behavioral aspects of crew selection."

A key concern for astronauts as well as during the stay on Mars is dangerous radiation in the form of storms of high-energy particles from the sun as well as cosmic rays from deep space. "The best radiation protection material is hydrogen, or water, which is rich in hydrogen," Drake said.

On the surface of Mars, NASA envisions that cargo deployed ahead of time can produce water before the crew arrives to use as a shield during the crew's stay there. On the way to and from Mars, the ship could be configured so that water and food surround areas where crew spend most of their time, but "a 'storm shelter' aboard the ship will be an integral part for short events of radiation that can be lethal," Drake said.

No firm date has been set for any potential Mars mission, but it remains of keen interest not just to NASA, but also others, such as China.

"It's humanity's next step to understanding and expanding our presence outward," Drake said. "We view human exploration of Mars as being an international endeavor, most likely not limited to just one country, but probably of global scale.

Former ?10th planet? officially named Eris

Once known as Xena, mini-world ignited debate over planethood

The mini-world formerly known as 2003 UB313 or Xena, shown in this artist?s conception, has received an official name from the International Astronomical Union: Eris. Its moon has been named Dysnomia.

LOS ANGELES - A distant, icy rock whose discovery shook up the solar system and led to Pluto?s planetary demise has been given a name: Eris.

The christening of Eris, named after the Greek goddess of chaos and strife, was announced by the International Astronomical Union on Wednesday. Weeks earlier, the professional astronomers? group stripped Pluto of its planethood under new controversial guidelines.

Since its discovery last year, Eris ignited a debate over what constitutes a planet.

Astronomers were split over how to classify the object ? which had been known as 2003 UB313, its provisional numerical designation; or as Xena, the informal code name that was chosen by its discoverers. Some argued that it should be welcomed as the 10th planet since it was larger than Pluto, but others felt Pluto was not a full-fledged planet.

After much bickering, astronomers last month voted to shrink the solar system to eight planets, downgrading Pluto to a ?dwarf planet,? a category that also includes Eris and the asteroid Ceres.

Eris? discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it ?too perfect to resist.?

In mythology, Eris caused a quarrel among goddesses that sparked the Trojan War. In real life, Eris forced scientists to define a planet that eventually led to Pluto getting the boot. Soon after Pluto?s dismissal from the club of classical planets, hundreds of scientists circulated a petition protesting the decision.

Moon also gets an official name
Eris? moon also received a formal name: Dysnomia, the daughter of Eris known as the spirit of lawlessness. Dysnomia is the object formerly known by the code name Gabrielle.

While waiting for an official designation, Brown and his colleagues reportedly used Xena as a code name because it called to mind the term ?Planet X,? which commonly referred to a mysterious 10th planet. The name also alluded to the title character in ?Xena: Warrior Princess,? a syndicated sword-and-sorcery TV series.

?It?s a little sad to see Xena go away,? Brown said.

In the TV show, Gabrielle was Xena?s sidekick. Coincidentally, Eris was also the name of a character in ?Xena: Warrior Princess.?

The dwarf planet Eris, which measures about 70 miles (110 kilometers) wider than Pluto, is the farthest known object in the solar system at 9 billion miles (14 billion kilometers) away from sun. It is also the third brightest object located in the Kuiper Belt, a disc of icy debris beyond the orbit of Neptune.

Found 20 light years away: the New Earth

It?s got the same climate as Earth, plus water and gravity. A newly discovered planet is the most stunning evidence that life - just like us - might be out there.

Above a calm, dark ocean, a huge, bloated red sun rises in the sky - a full ten times the size of our Sun as seen from Earth. Small waves lap at a sandy shore and on the beach, something stirs?

More?.

This is the scene - or may be the scene - on what is possibly the most extraordinary world to have been discovered by astronomers: the first truly Earth-like planet to have been found outside our Solar System.

The discovery was announced today by a team of European astronomers, using a telescope in La Silla in the Chilean Andes. If forced bookies to slash odds on the existence of alien beings.

The Earth-like planet that could be covered in oceans and may support life is 20.5 light years away, and has the right temperature to allow liquid water on its surface.

This remarkable discovery appears to confirm the suspicions of most astronomers that the universe is swarming with Earth-like worlds.

We don?t yet know much about this planet, but scientists believe that it may be the best candidate so far for supporting extraterrestrial life.

The new planet, which orbits a small, red star called Gliese 581, is about one-and-a-half times the diameter of the Earth.

It probably has a substantial atmosphere and may be covered with large amounts of water - necessary for life to evolve - and, most importantly, temperatures are very similar to those on our world.

It is the first exoplanet (a planet orbiting a star other than our own Sun) that is anything like our Earth.

Of the 220 or so exoplanets found to date, most have either been too big, made of gas rather than solid material, far too hot, or far too cold for life to survive.

?On the treasure map of the Universe, one would be tempted to mark this planet with an X,? says Xavier Delfosse, one of the scientists who discovered the planet.

?Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life.?

Gliese 581 is among the closest stars to us, just 20.5 light years away (about 120 trillion miles) in the constellation Libra. It is so dim it can be seen only with a good telescope.

Because all planets are relatively so small and the light they give off so faint compared to their sun, finding exoplanets is extremely difficult unless they are huge.

Those that have so far been detected have mostly been massive, Jupiter-like balls of gas that almost certainly cannot be home to life.

This new planet - known for the time being as Gliese 581c - is a midget in comparison, being about 12,000 miles across (Earth is a little under 8,000 pole-to-pole).

It has a mass five times that of Earth, probably made of the same sort of rock as makes up our world and with enough gravity to hold a substantial atmosphere.

Astrobiologists - scientists who study the possibility of alien life - refer to a climate known as the Goldilocks Zone, where it is not so cold that water freezes and not so hot that it boils, but where it can lie on the planet?s surface as a liquid.

In our solar system, only one planet - Earth -lies in the Goldilocks Zone. Venus is far too hot and Mars is just too cold. This new planet lies bang in the middle of the zone, with average surface temperatures estimated to be between zero and 40c (32-102f). Lakes, rivers and even oceans are possible.

It is not clear what this planet is made of. If it is rock, like the Earth, then its surface may be land, or a combination of land and ocean.

Another possibility is that Gliese 581c was formed mostly from ice far from the star (ice is a very common substance in the Universe), and moved to the close orbit it inhabits today.

In which case its entire surface will have melted to form a giant, planet-wide ocean with no land, save perhaps a few rocky islands or icebergs.

The surface gravity is probably around twice that of the Earth and the atmosphere could be similar to ours.

Although the new planet is in itself very Earth-like, its solar system is about as alien as could be imagined. The star at the centre - Gliese 581 - is small and dim, only about a third the size of our Sun and about 50 times cooler.

The two other planets are huge, Neptune-sized worlds called Gliese 581b and d (there is no ?a?, to avoid confusion with the star itself).

The Earth-like planet orbits its sun at a distance of only six million miles or so (our Sun is 93 million miles away), travelling so fast that its ?year? only lasts 13 of our days.

The parent star would dominate the view from the surface - a huge red ball of fire that must be a spectacular sight.

It is difficult to speculate what - if any - life there is on the planet. If there is life there it would have to cope with the higher gravity and solar radiation from its sun.

Just because Gliese 581c is habitable does not mean that it is inhabited, but we do know its sun is an ancient star - in fact, it is one of the oldest stars in the galaxy, and extremely stable. If there is life, it has had many billions of years to evolve.

This makes this planet a prime target in the search for life. According to Seth Shostak, of the Search for Extraterrestrial Intelligence Institute in California, the Gliese system is now a prime target for a radio search. ?We had actually looked at this system before but only for a few minutes. We heard nothing, but now we must look again.?

By 2020 at least one space telescope should be in orbit, with the capability of detecting signs of life on planets orbiting nearby stars. If oxygen or methane (tell-tale biological gases) are found in Gliese 581c?s atmosphere, this would be good circumstantial evidence for life.

Dr Malcolm Fridlund, a European Space Agency scientist, said the discovery of Gliese 581c was ?an important step? on the road to finding life.

?If this is a rocky planet, it?s very likely it will have liquid water on its surface, which means there may also be life.?

The real importance is not so much the discovery of this planet itself, but the fact that it shows that Earth-like planets are probably extremely common in the Universe.

There are 200 billion stars in our galaxy alone and many astronomers believe most of these stars have planets.

The fact that almost as soon as we have built a telescope capable of detecting small, earth-like worlds, one turns up right on our cosmic doorstep, shows that statistically, there are probably billions of earths out there.

As Seth Shostak says: ?We?ve never found one close to being like the Earth until now. We are finding that Earth is not such an unusual puppy in the litter of planets.?

But are these alien Earths home to life? No one knows. We don?t understand how life began on our world, let alone how it could arise anywhere else. There may be an awful lot of bugs and bacteria out there, and only a few worlds with what we would recognise as plants and animals. Or, of course, there may be nothing.

The Search for Extraterrestrial Intelligence Institute uses radio telescopes to try to pick up messages sent by alien civilisations.

Interestingly, Gliese 581c is so close to the Earth that if its putative inhabitants only had our level of technology, they could - just about - pick up some of our radio signals, such as the most powerful military transmitters. Quite what would happen if we for our part did receive a signal is unclear.

?There is a protocol, buried away in the United Nations,? says Dr Shostak. ?The President would be told first, after the signal was confirmed by other observatories. But we couldn?t keep such a discovery secret.?

It may be some time before we detect any such signals, but it is just possible that today we are closer than ever to finding life in the stars.

William Hill said it had shortened the odds on proving the existence of extraterrestrial intelligence from 1,000-1 to 100-1.

Spokesman Graham Sharpe said: ?We would face a possible eight-figure payout if it were to be confirmed that intelligent life of extra-terrestrial origin exists. We felt we had to react to the news that an earth-like planet which could support intelligent life had been discovered - after all, we don?t know for sure that intelligent extraterrestrial life has not already been discovered.?

The new planet, so far unnamed, is 20.5 light years away and orbits a red dwarf star called Gliese 581.