Tag Archive: Planets


Scientists find neighbour star with 6 planets, 3 of them capable of supporting life

A neighbour star has at least six planets in orbit, including three circling at the right distance for water to exist, a condition believed to be necessary for life, scientists said on Tuesday.

Previously, the star known as Gliese 667C was found to be hosting three planets, one of which was located in its so-called “habitable zone” where temperatures could support liquid surface water. That planet and two newly found sibling worlds are bigger than Earth, but smaller than Neptune.

“This is the first time that three such planets have been spotted orbiting in this zone in the same system,” astronomer Paul Butler, with the Carnegie Institution in Washington, D.C., said in a statement.

Scientists say the discovery of three planets in a star’s habitable zone raises the odds of finding Earth-like worlds where conditions might have been suitable for life to evolve.

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Hubble Space Telescope image - dubbed eXtreme Deep Field - of the universe. In the image are 5,000 galaxies. The image took 2,000 exposures lasting a total of 500 hours.

The Hubble Space Telescope (HST) has produced one of its most extraordinary views of the Universe to date.

Called the eXtreme Deep Field, the picture captures a mass of galaxies stretching back almost to the time when the first stars began to shine.

But this was no simple point and snap – some of the objects in this image are too distant and too faint for that.

Rather, this view required Hubble to stare at a tiny patch of sky for more than 500 hours to detect all the light.

“It’s a really spectacular image,” said Dr Michele Trenti, a science team member from the University of Cambridge, UK.

“We stared at this patch of sky for about 22 days, and have obtained a very deep view of the distant Universe, and therefore we see how galaxies were looking in its infancy.”

The XDF will become a tool for astronomy. The objects embedded in it can be followed up by other telescopes. It should keep scientists busy for years, enabling them to study the full history of galaxy formation and evolution.

The new vista is actually an updating of a previous HST product – the Hubble Ultra Deep Field.

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Image: Artist's illustration of the alien solar system Kepler-47

A new study shows that planetary systems can form and survive in the chaotic environment around pairs of stars.

A team reports in Science the discovery of two planets orbiting a pair of stars – a so-called binary.

Gravitational disturbances generated by stellar pairs are thought to be very severe for any orbiting planets.

Nasa’s Kepler space telescope found two small planets around a pair of low-mass stars.

Such systems have particular significance for science fiction fans. In the Star Wars films, Luke Skywalker’s home planet of Tatooine orbits a binary star.

The planetary system, known as Kepler-47, is located roughly 5,000 light-years away, in the constellation Cygnus.

It contains a pair of stars whizzing around each other every 7.5 days. One star is Sun-like, while the other is about one-third the size of its neighbour and 175 times fainter.

Circling the stars is an inner planet about three times larger in diameter than the Earth, and an outer planet that is just slightly larger than Uranus.

The inner planet – dubbed Kepler-47b – takes 49 days to complete an orbit, while the outer planet – Kepler-47c – takes 303 days.

The orbit of the outer planet places it in the so-called “habitable zone”, the region around a star where it is neither too cold nor too hot for liquid water to persist on the surface of a planet.

While the outer world is probably a gas-giant planet and thus not suitable for life, its discovery establishes that these “circumbinary” planets can, and do, exist in habitable zones.

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What Earth looked like from between 13 billion years ago to how it will likely look 250 million years in the future.

Harvard scientists use 1,024-core supercomputer to produce a partial simulation of the life of the universe, modelling thousands of individual stars and galaxies with a Arepo, new software for cosmological simulations of galaxy formation across billions of years.

An exotic planet that seems to be made of diamond racing around a tiny star in our galactic backyard in an undated image courtesy of Swinburne University of Technology in Melbourne. REUTERS/Handout

Astronomers have spotted an exotic planet that seems to be made of diamond racing around a tiny star in our galactic backyard.

The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.

“The evolutionary history and amazing density of the planet all suggest it is comprised of carbon — i.e. a massive diamond orbiting a neutron star every two hours in an orbit so tight it would fit inside our own Sun,” said Matthew Bailes of Swinburne University of Technology in Melbourne.

Lying 4,000 light years away, or around an eighth of the way toward the center of the Milky Way from the Earth, the planet is probably the remnant of a once-massive star that has lost its outer layers to the so-called pulsar star it orbits.

Pulsars are tiny, dead neutron stars that are only around 20 kilometers (12.4 miles) in diameter and spin hundreds of times a second, emitting beams of radiation.

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LONDON: Scientists claim to have discovered a potentially habitable planet which has an environment much similar to that of Earth and may contain water and even life.

The exoplanet, called Gliese 581g, is located around 123 trillion miles away from Earth and orbits a star at a distance that places it squarely in the habitable or the Goldilocks zone, the scientists said.

The research, published in a paper published in the Astrophysical Journal, suggests that the planet could contain liquid water on its surface, meaning it tops the league of planets and moons rated as being most like Earth, they said.

“Our findings offer a very compelling case for a potentially habitable planet said Vogt,” said lead researcher Steven Vogt, a professor of astronomy and astrophysics at the University of California.

“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,” Vogt said. The new findings are based on 11 years of observations of the nearby red dwarf star Gliese 581. The team reported the discovery of two new planets around Gliese 581.

This brings the total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own. Like our solar system, the planets around Gliese 581 have nearlycircular orbits, the team said.

It found that Gliese 581g has a mass three to four time the Earth’s and orbits its star in just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and enough gravity to hold on to an atmosphere, they said.

Ever since a study conducted back in 1993, it has been proposed that in order for a planet to support more complex life, it would be most advantageous for that planet to have a large moon orbiting it, much like the Earth’s moon. Our moon helps to stabilize the Earth’s rotational axis against perturbations caused by the gravitational influence of Jupiter. Without that stabilizing force, there would be huge climate fluctuations caused by the tilt of Earth’s axis swinging between about 0 and 85 degrees.

But now that belief is being called into question thanks to newer research, which may mean that the number of planets capable of supporting complex life could be even higher than previously thought.

Since planets with relatively large moons are thought to be fairly rare, that would mean most terrestrial-type planets like Earth would have either smaller moons or no moons at all, limiting their potential to support life. But if the new research results are right, the dependence on a large moon might not be as important after all. “There could be a lot more habitable worlds out there,” according to Jack Lissauer of NASA’s Ames Research Center in Moffett Field, California, who leads the research team.

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Kepler 21b

The National Optical Astronomy Observatory announced on Wednesday the discovery of Kepler-21b, a new planet that’s close to the size of earth and is only about 352 light years away.

“By astronomical standards, that’s right next door,” Katy Garmany, the Deputy Press Officer at the National Optical Astronomy Observatory.

Astronomers frequently discover new planets (according to Time magazine, we’re up to over 2,000), but Garmany said that what’s exciting about Kepler 21-b is that the planet is relatively Earth-sized. While its mass is about 10 times the size of our planet, its radius is only 1.6 times the size of Earth’s.

“Until a few years ago, the smallest extra-solar planet that we had discovered was the size of Jupiter or Saturn, which are about ten times bigger than the Earth,” Garmany said. “Now we’re getting down to something almost the size of the Earth, showing that we have the technology to find the earth-size planets.”

The new planet has a star that’s just a bit bigger and hotter than Earth’s sun, although it’s substantially younger. But because the planet is so close to its star, it’s far too hot to have liquid water, the base for life as we know it. At only 6 million kilometers (about 3.7 million miles) away from the star, Kepler-21b’s temperature is a blistering 2,960 degrees Fahrenheit, according to scientists’ estimates.

By contrast, Earth is about 150,000,000 km (93 million miles) from its own sun.

The discovery of Kepler-21b was a collaboration of both sky (the Kepler observatory) and ground-based telescopes at the Kitt Peak National Observatory in Arizona.

Phil Plait, the Bad Astronomer, writes in Discover Magazine that researchers examined the planet for 15 months. The results of the study will be published in Astrophysical Journal.

The Visible Universe, Then and Now

Before the telescope was invented in 1608, our picture of the universe consisted of six planets, our moon, the sun and any stars we could see in the Milky Way galaxy. But as our light-gathering capabilities have grown, so too have the boundaries of the visible universe. Our interactive map shows how the known universe has grown from 1950 to 2011.

In the late 1700s, William Herschel, an English astronomer using a telescope with an 18.7-inch aperture, made the first systematic surveys of the skies, revealing more than 2,000 distant galaxies, nebulae and other objects invisible to the naked eye. Since then, increasingly powerful optical and radio telescopes have greatly expanded our store of knowledge.

In 1948, astronomers erected the 200-inch Hale Telescope at Palomar Observatory in California, and now, large-scale projects such as the Sloan Digital Sky Survey and NASA’s Kepler mission use sensitive digital imaging and computational power to collect and analyze hundreds of terabytes of data on millions of galaxies billions of light-years from Earth. With each additional bit of data, the universe itself grows larger.

One of the great mysteries of planetary science is how Earth got so wet. By the time our planet formed about 4.5 billion years ago, the Sun’s heat had driven most of the Solar System’s complement of water out toward the edges. Most of it is still there, frozen solid in, among other things, the rings of Saturn, Jupiter’s moon Europa, the bodies of Neptune and Uranus and billions upon billions of comets.

But the Earth has plenty of water as well, and scientists have wondered for years how it got here. One leading theory: it came from a fusillade of comets that came screaming back in toward the Sun a half-billion years or so after our planet formed. That idea got a big boost just last week with the discovery that some comets, at least, have the same chemical signature as the water found on Earth.

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The first direct image of a planet in the process of forming around its star has been captured by astronomers who combined the power of the 10-meter Keck telescopes with a bit of optical sleight of hand.

What astronomers are calling LkCa 15 b, looks like a hot “protoplanet” surrounded by a swath of cooler dust and gas, which is falling into the still-forming planet. Images have revealed that the forming planet sits inside a wide gap between the young parent star and an outer disk of dust.

“LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder,” said astronomer Adam Kraus of the University of Hawaii’s Institute for Astronomy. “This young gas giant is being built out of the dust and gas. In the past, you couldn’t measure this kind of phenomenon because it’s happening so close to the star. But, for the first time, we’ve been able to directly measure the planet itself as well as the dusty matter around it.”

Youngest planet seen as it's forming

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