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Peter Lemkin
01-04-2013, 07:38 PM
'Earth-Like' Planet Discovered By Scientists
12:41am UK, Wednesday 19 December 2012

Scientists have discovered a planet with conditions that could support life - orbiting a sun that is visible to the naked eye.
Tau Ceti is thought to be the lowest mass solar system yet detected

The world is one of five thought to be circling Tau Ceti, a star 12 light years away which is almost identical to the sun.

Astronomers estimate the Tau Ceti planets to be two to six times bigger than Earth. And one of them, with five times the Earth's mass, lies in the star's "habitable zone".

The orbital region is also known as the 'Goldilocks zone', as it is neither too hot nor too cold to allow liquid surface water and, potentially, life.

Details of the discovery are to appear in the journal Astronomy & Astrophysics.

Scientists found the Tau Ceti planetary family using a highly sensitive technique that combined data from more than 6,000 observations from three different telescopes.

Dr James Jenkins, a member of the international team from the University of Hertfordshire, said: "Tau Ceti is one of our nearest cosmic neighbours and so bright that we may be able to study the atmospheres of these planets in the not-too-distant future.

"Planetary systems found around nearby stars close to our sun indicate that these systems are common in our Milky Way galaxy."

More than 800 planets have been discovered orbiting stars beyond the sun since the 1990s.

Those found around the nearest sun-like stars are the most interesting to astronomers.

Professor Steve Vogt, another team member, from the University of California at Santa Cruz, said: "This discovery is in keeping with our emerging view that virtually every star has planets, and that the galaxy must have many such potentially habitable Earth-sized planets.

"They are everywhere, even right next door." :popworm:

Peter Lemkin
01-04-2013, 07:51 PM
Billions of planets in every galaxy the norm, says new study




One of the reasons science loves raw numbers is because numbers can reveal things that aren't immediately obvious to our pattern recognition-dependent brains. That's why a new study that attempts to pin a number on the amount of planets in a normal galaxy offers so much promise for the future of interplanetary exploration.

In a new study conducted by the California Institute of Technology (Caltech), astronomers have concluded that, based on estimates of the number of planets in our own galaxy, the universe contains more planets than we could ever visit, even if we had something like the fictional warp drive-capable starship Enterprise. The study's author, John Johnson, assistant professor of planetary astronomy at Caltech, said, "There's at least 100 billion planets in the galaxy — just our galaxy. That's mind-boggling."

The estimates are based on the analysis of the planets surrounding the star known as Kepler-32. Kepler-32 makes for a good candidate in that it's an M-dwarf star system, the most common kind of star in our Milky Way galaxy. From NASA's Jet Propulsion Laboratory:
"M-dwarf systems like Kepler-32's are quite different from our own solar system. For one, M dwarfs are cooler and much smaller than the sun. Kepler-32, for example, has half the mass of the sun and half its radius. The radii of its five planets range from 0.8 to 2.7 times that of Earth, and those planets orbit extremely close to their star. The whole Kepler-32 system fits within just over a tenth of an astronomical unit (the average distance between Earth and the sun) — a distance that is about a third of the radius of Mercury's orbit around the sun."

Extrapolating forward, the researchers determined that there is at least one planet for every one of the roughly 100 billion stars in our galaxy. This probably means that those exciting announcements about finding distant Earth-like planets are likely to increase in coming years. Though, none that we've spotted to date are quite what we're looking for in an exoplanet.

Even still, such prospects could help to further spur the development of commercial space ventures, as the riches of space beckon. But the other, unmentioned aspect of this finding will be obvious to most: If planets are that ubiquitous, how can we continue to even question that, statistically, there is likely another form of intelligent life somewhere out there amongst the billions and billions of planets?