Most Earth-Like Planets

planet_alien

Selain dari bumi kemungkinan besar (menurut saintis) terdapat lebih kurang 3 buah planet yang boleh di diami oleh manusia.  (Kemungkinan besar lebih banyak Planet dijumpai, tapi belum dicanangkan antaranya GJ1214B)  Namun jaraknya yang terlalu jauh menyebabkan semuanya menjadi mustahil untuk manusia pergi ke sana. Untuk menghantar satu krew seperti yang di laporkan baru-baru ini ke Planet Marikh (Mars) sahaja perjalanan mengambil masa 8 bulan. —->>http://www.mars-one.com/ Mereka yang diterbangkan ke Marikh tersebut  tidak akan kembali ke bumi lagi. Kos untuk membawa mereka balik sahaja terlalu tinggi. Makanya mereka akan pergi ke sana menggunakan tiket sehala (one way ticket). Mereka akan menjadi imigran dari bumi dan akan menjadi peneroka. Jika segala kajian tentang persekitaran adalah betul seperti yang direkod, manusia yang pergi ke sana mungkin dapat hidup seperti biasa. Namun jika tidak makanya mereka akan berkorban nyawa kerana mereka tidak boleh kembali ke bumi.

Selain dari Marikh yang sekian lama dinobatkan sebagai planet Bumi kedua kini ada  3 lagi planet yang boleh di diami. Menurut kajian saintis menerusi teropong khas Kepler (NASA) mereka telah menjumpai Planet Kepler-62E, Kepler-62f dan Kepler-69c. Planet Kepler 62E mempunyai keluasan sebesar 1.6 x  planet bumi. Mempunyai tanda-tanda kehadiran air. Planet Kepler-62f  pula mempunyai keluasan 1.4 besarnya dari planet bumi. Planet ketiga Kepler-69 pula mempunyai keluasan lebih besar iaitu 1.7 x. Kesemua planet ini kemungkinan boleh didiami manusia dan kemungkinan besar juga telah ada makhluk mendiami planet ini sebelum ini.

Untuk mengetahui lebih lanjut boleh di dapati di laman web  http://www.space.com atau baca copy di bawah ini….

Discovered! Most Earth-Like Alien Planet & 2 Other Possibly Habitable Worlds

Newfound Habitable-Zone Exoplanet Kepler-69f

This artist’s concept depicts Kepler-62f, a planet 1.4 times the size of Earth that circles in the habitable zone of its host star. The small shining object at right is Kepler-62e, another potentially habitable world in the five-planet system.
Credit: NASA/Ames/JPL-Caltech

NASA’s Kepler space telescope has discovered three exoplanets that may be capable of supporting life, and one of them is perhaps the most Earth-like alien world spotted to date, scientists announced today (April 18).

That most intriguing one is called Kepler-62f, a rocky world just 1.4 times bigger than Earth that circles a star smaller and dimmer than the sun. Kepler-62f’s newfound neighbor, Kepler-62e, is just 1.6 times larger than Earth, making the pair among the smallest exoplanets yet found in their star’s habitable zone — the just-right range of distances where liquid water can exist on a world’s surface.

Kepler-62e and f, which are part of a newly discovered five-planet system, “look very good as possibilities for looking for life,” said Kepler science principal investigator Bill Borucki, of NASA’s Ames Research Center in Moffett Field, Calif. [Three Possibly Habitable Super-Earths Found (Gallery)]

The third potentially habitable planet, called Kepler-69c, is 1.7 times bigger than Earth and orbits a star similar to our own. It’s the smallest world ever found in the habitable zone of a sunlike star, researchers said, and represents a big step toward discovering the first-ever “alien Earth.”

“We’re moving very rapidly toward finding an Earth analogue around a star like the sun,” Borucki told SPACE.com.

Researchers announced these newfound planets — all three of which are “super-Earths,” or worlds slightly larger than our own — today at a NASA news conference. The Kepler-62 discovery paper, led by Borucki, was also published today in the journal Science; the Kepler-69 study, led by Thomas Barclay of the Bay Area Environmental Research Institute in Sonoma, Calif., appeared today in The Astrophysical Journal.

The three potentially habitable worlds are part of a larger haul. All told, the scientists rolled out seven new exoplanets today — five in the Kepler-62 system and two in Kepler-69.

Alien water worlds?

The five newfound planets in the Kepler-62 system, which is located about 1,200 light-years away in the constellation Lyra, range from 0.54 to 1.95 times the size of Earth. Only Kepler-62e and f are potentially habitable; the other three zip around the star at close range, making them too hot to support life as we know it, researchers said.

Kepler-62e and f take 122 and 267 days, respectively, to complete one orbit around their star, which is just 20 percent as bright as the sun. While nobody knows what the two exoplanets look like, a separate modeling study suggests they’re both probably water worlds covered by endless, uninterrupted global oceans. [Two Habitable Alien Water Worlds? (Video)]

“There may be life there, but could it be technology-based like ours? Life on these worlds would be under water with no easy access to metals, to electricity, or fire for metallurgy,” lead author Lisa Kaltenegger, of the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics, said in a statement.

“Nonetheless, these worlds will still be beautiful blue planets circling an orange star — and maybe life’s inventiveness to get to a technology stage will surprise us,” she added.

Not surprisingly, Kepler-62e should be warmer than its more distantly orbiting neighbor. In fact, Kepler-62f may require a greenhouse effect to keep its ocean from freezing over, researchers said.

“Kepler-62e probably has a very cloudy sky and is warm and humid all the way to the polar regions,” co-author Dimitar Sasselov of Harvard said in a statement. “Kepler-62f would be cooler, but still potentially life-friendly.”

The new modeling study has been accepted for publication in The Astrophysical Journal.

Diagram of Kepler-62 Planetary System

This diagram compares the planets of the inner solar system to Kepler-62, a newfound five-planet system with two potentially habitable worlds. Kepler-62 lies about 1,200 light-years from Earth, in the constellation Lyra.
Credit: NASA/Ames/JPL-Caltech

Searching for Earth’s twin

The $600 million Kepler observatory launched in March 2009 to hunt for Earth-size exoplanets in the habitable zone of their parent stars. Kepler finds alien worlds by detecting the tiny brightness dips caused when they transit, or cross the face of, their stars from the instrument’s perspective.

Newfound 'Super-Venus' Kepler-69c
The artist’s concept depicts Kepler-69c, a planet 1.7 times the size of Earth that orbits in the habitable zone of a star like our sun, located about 2,700 light-years from Earth in the constellation Cygnus.
Credit: NASA/Ames/JPL-Caltech

Kepler has used this technique to great effect, spotting more than 2,700 potential planets since its March 2009 launch. While just 120 or so of these candidates have been confirmed to date, mission scientists estimate that more than 90 percent will end up being the real deal.

While Kepler has yet to discover a true Earth twin, it’s getting closer and closer, Borucki said, pointing to the confirmation of Kepler-69c as an example. (That planet lies 2,700 light-years away, in the constellation Cygnus. Kepler-69c’s neighbor Kepler-69b, which is about twice the size of Earth and too hot to host life, was also announced today.)

“I think we’re making excellent progress in that direction,” Borucki said. “We have a number of candidates that look good.”

Such steady progress makes sense, since Kepler will of course spot more transits the longer it looks. The telescope needs to observe three transits to flag a planet candidate, so detecting a potentially habitable world in a relatively distant orbit can take several years.

Kepler cannot search for signs of life on worlds like Kepler-62e, Kepler-62f and Kepler-69c, but the telescope is paving the way for future missions that should do just that, Borucki said.

“This is one of the early steps, but there’s no mistake — we are on our way to explore the galaxy, to learn about life in the galaxy,” he said.

Clouds Detected on Alien Planet –New Hubble Discovery

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Weather forecasters on exoplanet GJ 1214b would have an easy job. Today’s forecast: cloudy. Tomorrow: overcast. Extended outlook: more clouds. A team of scientists led by researchers in the Department of Astronomy and Astrophysics at the University of Chicago report they have definitively characterized the atmosphere of a super-Earth class planet orbiting another star for the first time.

 

The scrutinized planet, which is known as GJ1214b, is classified as a super-Earth type planet because its mass is intermediate between those of Earth and Neptune. Recent searches for planets around other stars (“exoplanets”) have shown that super-Earths like GJ 1214b are among the most common type of planets in the Milky Way galaxy. Because no such planets exist in our Solar System, the physical nature of super-Earths is largely unknown.Previous studies of GJ 1214b yielded two possible interpretations of the planet’s atmosphere. Its atmosphere could consist entirely of water vapor or some other type of heavy molecule, or it could contain high-altitude clouds that prevent the observation of what lies underneath.But now a team of astronomers led by University of Chicago’s Laura Kreidberg and Jacob Bean have detected clear evidence of clouds in the atmosphere of GJ 1214b from data collected with the Hubble Space Telescope. The Hubble observations used 96 hours of telescope time spread over 11 months. This was the largest Hubble program ever devoted to studying a single exoplanet.

The researchers describe their work as an important milestone on the road to identifying potentially habitable, Earth-like planets beyond our Solar System. The results appear in the Jan. 2 issue of the journal Nature.

“We really pushed the limits of what is possible with Hubble to make this measurement,” said Kreidberg, a third-year graduate student and first author of the new paper. “This advance lays the foundation for characterizing other Earths with similar techniques.”

“I think it’s very exciting that we can use a telescope like Hubble that was never designed with this in mind, do these kinds of observations with such exquisite precision, and really nail down some property of a small planet orbiting a distant star,” explained Bean, an assistant professor and the project’s principal investigator.

GJ 1214b is located just 40 light-years from Earth, in the direction of the constellation Ophiuchus. Because of its proximity to our solar system and the small size of its host star, GJ 1214b is the most easily observed super-Earth. It transits, or passes in front of its parent star, every 38 hours, giving scientists an opportunity to study its atmosphere as starlight filters through it.

Kreidberg, Bean and their colleagues used Hubble to precisely measure the spectrum of GJ 1214b in near-infrared light, finding what they consider definitive evidence of high clouds blanketing the planet. These clouds hide any information about the composition and behavior of the lower atmosphere and surface.

The planet was discovered in 2009 by the MEarth Project, which monitors two thousand red dwarf stars for transiting planets. The planet was next targeted for follow-up observations to characterize its atmosphere. The first spectra, which were obtained by Bean in 2010 using a ground-based telescope, suggested that the planet’s atmosphere either was predominantly water vapor or hydrogen-dominated with high-altitude clouds.

More precise Hubble observations made in 2012 and 2013 allowed the team to distinguish between these two scenarios. The news is about what they didn’t find. The Hubble spectra revealed no chemical fingerprints whatsoever in the planet’s atmosphere. This allowed the astronomers to rule out cloud-free atmospheres made of water vapor, methane, nitrogen, carbon monoxide, or carbon dioxide.

The best explanation for the new data is that there are high-altitude clouds in the atmosphere of the planet, though their composition is unknown. Models of super-Earth atmospheres predict clouds could be made out of potassium chloride or zinc sulfide at the scorching temperatures of 450 degrees Fahrenheit found on GJ 1214b. “You would expect very different kinds of clouds to form than you would expect, say, on Earth,” Kreidberg said.

The launch of NASA’s next major space telescope, the 6.5m James Webb Space Telescope(JWST), later this decade should reveal more about such worlds, Kreidberg said. “Looking forward, JWST will be transformative,” she said. “The new capabilities of this telescope will allow us to peer through the clouds on planets like GJ 1214b. But more than that, it may open the door to studies of Earth-like planets around nearby stars.”

Source: “Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b,” by Laura Kreidberg, Jacob L. Bean, Jean-Michel Désert, Björn Benneke, Drake Deming, Kevin B. Stevenson, Sara Seager, Zachory Berta-Thompson, Andreas Seifahrt, & Derek Homeier.

The Daily Galaxy via http://news.uchicago.edu/

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