Another 'Earth' found
PostPosted:Fri Dec 09, 2011 6:41 am
http://www.youtube.com/watch?v=ADFeSFkgwUI
This is a quote from this link:
http://www.smh.com.au/world/science/ano ... 15zdz.html
WASHINGTON: For the first time, astronomers have detected a planet in another solar system that has the essential conditions needed to support life.
The presence of Earth-like planets outside our solar system, in what is called the ''habitable zone'', has been predicted for some time, but identifying and measuring one marks the beginning of a new era in the search for life beyond Earth.
''This is our first Goldilocks planet - just the right size and the right distance from its sun. A threshold has been reached,'' said Paul Butler, an astronomer and ''planet-hunter'' at the Carnegie Institution of Washington.
The planet is orbiting in the middle of the habitable zone of the red dwarf star Gliese 581, which means it could have water on its surface. Named Gliese 581g, it has a mass three to four times that of Earth and an orbital period of just under 37 days.
Its mass indicates that it is probably a rocky planet and has enough gravity to hold on to an atmosphere, said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, and one of the leaders of the team that discovered the planet.
If Gliese 581g has a rocky composition similar to Earth's, its diameter would be about 1.2 to 1.4 times that of Earth, the researchers said.
The surface gravity would be about the same or slightly higher than Earth's, so that a person could easily walk upright on the planet, Dr Vogt said.
Gliese 581g was discovered by scientists working on the Lick-Carnegie Exoplanet Survey, during 11 years of observing the red dwarf star Gliese 581, which is 20 light years from Earth.
For astronomers, 11 years of observation is considered a short time and 20 light years, which is about 188 trillion kilometres, rather close.
''The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common,'' Dr Vogt said.
The planet is tidally locked to its star, meaning one side always faces the star, basking in perpetual daylight, and the other is in perpetual darkness because it faces away from the star. This makes the line between darkness and light, known as the ''terminator'', the most habitable part.
The researchers estimate that the average surface temperature of the planet would be between -31 and -12 degrees. But actual temperatures would range from ''blazing hot on the side facing the star, to freezing cold on the dark side'', they said.
The findings, published in the Astrophysical Journal ''offer a very compelling case for a potentially habitable planet,'' said Dr Vogt.
In their report, the scientists in fact announce the discovery of two new planets around Gliese 581. The star is now known to have six, and perhaps seven, planets orbiting it. Unlike most distant solar systems detected, the planets all orbit in a circular path and are lined up in a way similar to our solar system.
''As we collect more data, we can see the system looks like our own, with an inner clutch of rocky, terrestrial planets and then a big loner, like Jupiter, further out,'' Dr Vogt said.
This is a quote from this link:
http://www.smh.com.au/world/science/ano ... 15zdz.html
WASHINGTON: For the first time, astronomers have detected a planet in another solar system that has the essential conditions needed to support life.
The presence of Earth-like planets outside our solar system, in what is called the ''habitable zone'', has been predicted for some time, but identifying and measuring one marks the beginning of a new era in the search for life beyond Earth.
''This is our first Goldilocks planet - just the right size and the right distance from its sun. A threshold has been reached,'' said Paul Butler, an astronomer and ''planet-hunter'' at the Carnegie Institution of Washington.
The planet is orbiting in the middle of the habitable zone of the red dwarf star Gliese 581, which means it could have water on its surface. Named Gliese 581g, it has a mass three to four times that of Earth and an orbital period of just under 37 days.
Its mass indicates that it is probably a rocky planet and has enough gravity to hold on to an atmosphere, said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, and one of the leaders of the team that discovered the planet.
If Gliese 581g has a rocky composition similar to Earth's, its diameter would be about 1.2 to 1.4 times that of Earth, the researchers said.
The surface gravity would be about the same or slightly higher than Earth's, so that a person could easily walk upright on the planet, Dr Vogt said.
Gliese 581g was discovered by scientists working on the Lick-Carnegie Exoplanet Survey, during 11 years of observing the red dwarf star Gliese 581, which is 20 light years from Earth.
For astronomers, 11 years of observation is considered a short time and 20 light years, which is about 188 trillion kilometres, rather close.
''The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common,'' Dr Vogt said.
The planet is tidally locked to its star, meaning one side always faces the star, basking in perpetual daylight, and the other is in perpetual darkness because it faces away from the star. This makes the line between darkness and light, known as the ''terminator'', the most habitable part.
The researchers estimate that the average surface temperature of the planet would be between -31 and -12 degrees. But actual temperatures would range from ''blazing hot on the side facing the star, to freezing cold on the dark side'', they said.
The findings, published in the Astrophysical Journal ''offer a very compelling case for a potentially habitable planet,'' said Dr Vogt.
In their report, the scientists in fact announce the discovery of two new planets around Gliese 581. The star is now known to have six, and perhaps seven, planets orbiting it. Unlike most distant solar systems detected, the planets all orbit in a circular path and are lined up in a way similar to our solar system.
''As we collect more data, we can see the system looks like our own, with an inner clutch of rocky, terrestrial planets and then a big loner, like Jupiter, further out,'' Dr Vogt said.
