Posted by: garispang | June 28, 2009

Astronomers find first habitable Earth-like planet (Inspired by Movie: Knowing)

knowing-movie-nicolascage

I was inspired by watching a Sci-Fiction thriller movie; ‘Knowing’ starr by Nicolas Cage.

Director Alex Proyas has enrolled Nicolas Cage in Knowing, an upcoming science-fiction thriller movie revolving around the story of a professor who’s trying to prevent the end of the world.

In the moive there is a pattern to predicting the future. There is an order to our deepest fears.

From the director of I
How do you protect who you love from everything you know?

The post-production team had time to add some more special effects so this brand new knowing movie trailer is way than the previous one. The plot of Knowing seems also more deeply thought than we have first expected: who are those bogeymen? The Angel of the Apocalypse or messengers from an other time or dimension?

And after watching the show, I began to research of finding out is  there an answer to of other alternative should this situation if it really happened to Earth. Here is my find out;

Planetary System Gliese 581

Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses. This exoplanet – as astronomers call planets around a star other than the Sun – is the smallest ever found up to now and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581, is smaller and colder than the Sun – and thus less luminous – the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid!

“We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid,” explains Stéphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result. “Moreover, its radius should be only 1.5 times the Earth’s radius, and models predict that the planet should be either rocky – like our Earth – or covered with oceans,” he adds.

“Liquid water is critical to life as we know it,” avows Xavier Delfosse, a member of the team from Grenoble University (France). “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 extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X.”

The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra (“the Scales”). It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class.

“Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun,” emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method [3], the most successful in detecting exoplanets.

Two years ago, the same team of astronomers already found a planet around Gliese 581. With a mass of 15 Earth-masses, i.e. similar to that of Neptune, it orbits its host star in 5.4 days. At the time, the astronomers had already seen hints of another planet. They therefore obtained a new set of measurements and found the new super-Earth, but also clear indications for another one, an 8 Earth-mass planet completing an orbit in 84 days. The planetary system surrounding Gliese 581 contains thus no fewer than 3 planets of 15 Earth masses or less, and as such is a quite remarkable system.

The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another ‘Trio of Neptunes’.

The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That’s the speed of a person walking briskly. Such tiny signals could not have been distinguished from ‘simple noise’ by most of today’s available spectrographs.

“HARPS is a unique planet hunting machine,” says Michel Mayor, from Geneva Observatory, and HARPS Principal Investigator. “Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!”

HARPS is also very efficient in finding planetary systems, where tiny signals have to be uncovered. The two systems known to have three low mass planets – HD 69830 and Gl 581 – were discovered by HARPS.

“And we are confident that, given the results obtained so far, finding a planet with the mass of the Earth around a red dwarf is within reach,” affirms Mayor.

This research is reported in a paper submitted as a Letter to the Editor of Astronomy and Astrophysics (“The HARPS search for southern extra-solar planets : XI. An habitable super-Earth (5 MEarth) in a 3-planet system”, by S. Udry et al.)

The team is composed of Stéphane Udry, Michel Mayor, Christophe Lovis, Francesco Pepe, and Didier Queloz (Geneva Observatory, Switzerland), Xavier Bonfils (Lisbonne Observatory, Portugal), Xavier Delfosse, Thierry Forveille, and C.Perrier (LAOG, Grenoble, France), François Bouchy (Institut d’Astrophysique de Paris, France), and Jean-Luc Bertaux (Service d’Aéronomie du CNRS, France)

exoplanet-life-search

Astronomers discover new way to search for life elsewhere through directly observing planets outside our solar system – called exoplanets – is almost impossible because they are washed out by the glare of the parent star. For this reason astronomers have largely relied on indirect methods that observe the effects of the planets on their parent stars instead of the planets themselves. Such indirect detection methods have helped take the number of exoplanets discovered so far to more than 350, but determining whether signs of life exist on a planet that can’t actually be seen presents a problem. Astronomers from the Instituto de Astrofisica de Canarias (IAC) have found a solution.

When a planet passes in front of its parent star, part of the starlight passes through the planet’s atmosphere. This is called the transmission spectrum and it provides vital information about the planet itself including information about the constituents of the atmosphere. While the team wasn’t able to use this exact method to look at the Earth’s atmosphere, they were able to measure the transmission spectrum of the Earth for the first time by observing light reflected from the Moon towards the Earth during a lunar eclipse.

The spectrum not only contained identifiable signs of life, but these signs were unmistakably strong. It also contained unexpected molecular bands and the signature of the earth ionosphere. These results provide astronomers with an idea of what the transmission spectrum of an inhabited planet looks like, so we now have a much better idea of how to find and recognize Earth like planets outside our solar system where life may be thriving.

The past two decades have witnessed the discovery of hundreds of exoplanets, and the discovery of many Earth-size planets are expected in coming decades. By confirming that observing the transmission spectrum is an effective way to gather information about the biological processes taking place on a planet, the team has vastly improved the chances of finding alien life on exoplanets.

The team from the Instituto de Astrofisica de Canarias (IAC) used the Science and Technology Facilities Council’s (STFC) William Herschel Telescope (WHT) on La Palma and the Nordic Optical Telescope (NOT) to conduct their research, which is published in the June 11 edition of Nature.

Fomalhaut System

Historic pics show worlds beyond our solar system. In two separate scientific show-stoppers, unprecedented direct images of planets outside of our own solar system have been captured by NASA’s Hubble space telescope and terrestrial observatories in Hawaii. Over the past two decades astronomers have detected around 300 exoplanets and are rapidly finding more, but these have mostly been observed by methods such as monitoring the gravitational effects of a planet on its parent star rather than seen as a direct optical image. We now have the first visible-light snapshot of a planet circling another star from the Hubble, and the first-ever direct images of an exoplanetary system from the massive 8-meter Gemini North telescope on Mauna Kea.

The Hubble image is of the planet Fomalhaut b, a body more than three times the mass of Jupiter orbiting a bright southern star (Fomalhaut) which can be seen with the naked eye. The image has been taken using a coronagraph to block-out the bright light from the star, which is why the center of the image is black. Fomalhaut b, which lies 10.7 billion miles from the star, is highlighted on the right. It may not look like as cool as the artists impression, but its a very significant little dot.

The dusty ring that can be seen encircling the star is what lead scientists to point the Hubble at Fomalhaut in the first place. The existence of this debris belt has been known about for some time and in 2005 Hubble astronomer Paul Kalas proposed that its elliptical shape and sharp inner-edge was the result of the a planet orbiting the star. He was right.

The image also shows the path of the planets orbit using data from observations made 21 months apart. The next step is to look for evidence of water vapor clouds in the planet’s atmosphere using infrared light, a task which the James Webb Space Telescope will be designed to accomplish when launched in 2013.

The near-Infrared image image produced by astronomers using the Gemini and Keck observatories is the first ever taken of a multi-planet system planets around a normal star outside of our solar system according to the research teams leader Dr. Christian Marois of the National Research Council of Canada’s Herzberg Institute of Astrophysics.

The host star (HR 8799) is about 1.5 times the mass of the Sun and is further away than Fomalhaut at about 130 light years away from Earth (though still faintly visible to the naked eye). The planets observed are also more massive than Fomalhaut b at about seven and ten times the mass of Jupiter, orbit HR 8799 at distances of 3.6 billion miles and 6.3 billion miles respectively and are young enough, at about sixty million years old, to retain glowing from heat from their formation. The planetary family is completed by a third planet not visible in the image that orbits closer to the star.

For further reading see the NASA and Gemini Observatory websites. A useful summary of the numerous methods used to detect exoplanets can also be found here.

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