The Godzilla Of Earths

The "Godzilla of Earths!" is in the foreground. Behind it is the smaller 'lava world'. Their sun, in the back, appears to have been created only 3 billion years after the Big Bang.

Based on what we know about how solar systems form, researchers thought that a giant rocky planet could not exist. But they just found one that's 17 times Earth's mass. They're calling it the Mega-Earth.

Scientists say the new planet may have "profound implications for the possibility of life" on extra-solar planets, according to a press release from the Harvard-Smithsonian Center for Astrophysics. They announced the finding in a talk at the American Astronomical Society meeting in Boston.

Researchers have always thought Mega-Earths were impossible since any planets that big would attract hydrogen gas, forming a gas planet like Jupiter.

Meet The Mega-Earth

Mega-Earth, also known as Kepler-10c, is 18,000 miles in diameter and 2.3 times as large as Earth. It appears to be as solid as the planet beneath our feet.

Kepler-10c was previously known to astronomers, but they had not yet measured its mass. Due to its size — 2.3 times that of Earth — it was assumed to be a "mini-Neptune," a planet encased in thick gas. But the new observations have confirmed that it is rocky, not gassy.

It orbits an 11 billion-year-old star named Kepler-10 located 560 light years away from Earth. Its year lasts only 45 days.

Interestingly, this solar system is more than twice as old as our own — it was born less than 3 billion years after the Big Bang.

A Mysterious System

Researchers had previously thought that this kind of planet impossible.

Not only did they think something that big would be a gas giant, but they didn't even think the elements that make up a rocky planet existed in our universe when this solar system was born: The early universe had only the lighter elements of hydrogen and helium. Heavier elements were forged from these lighter ones in stars over billions of years.

Because of this, many scientists hadn't been looking for rocky planets in these very old solar systems.

The mega-Earth isn't the only weird planet in its solar system. There's also a 'lava-world' 1.5 times Earth's size whose year lasts only 20 hours.

By David A. Aguilar

The Search For Earth-Like Planets

The search for Earth-like planets is reaching a fever-pitch. Does the evidence so far help shed light on the ancient question: Is the galaxy filled with life, or is Earth just a beautiful, lonely aberration? If things dont work out on this planet Or if our itch to explore becomes unbearable at some point in the future Astronomers have recently found out what kind of galactic real estate might be available to us. Well have to develop advanced transport to land there, 20 light years away. The question right now: is it worth the trip?

If things don't work out on this planet...

Or if our itch to explore becomes unbearable at some point in the future... 

Astronomers have recently found out what kind of galactic real estate might be available to us.

We'll have to develop advanced transport to land there, 20 light years away.... But that's for later.

The question right now: is it worth the trip? The destination is a star that you can't see with your naked eye, in the southern constellation Libra, called Gliese 581. 

Identified over 40 years ago by the German astronomer Wilhelm Gliese, it's a red dwarf with 31% of the Sun's mass... and only 1.3% of its luminosity. 

Until recently, the so-called M Stars like Gliese 581 flew below the radar of planet hunters. 

They give off so little energy that a planet would have to orbit dangerously close just to get enough heat. 

Now, these unlikely realms are beginning to show some promise... as their dim light yields to precision technologies... 

...as well as supercomputers... honed in the battle to understand global changes on this planet... Earth. 

Will we now begin to detect signs of alien life? 

Or will these worlds, and the galaxy itself, turn out to be lifeless... and Earth, just a beautiful, lonely aberration?

To some, like astronomer and author Carl Sagan, the sheer number and diversity of stars makes it, as he said, "far more likely that the universe is brimming over with life."

This so-called "many worlds" view can be traced back to ancient observers... in China, India, Greece and Egypt. The Qur'an, the Talmud, and many Hindu texts all imagined a universe full of living beings. 

In the 16th Century, this view got a boost from astronomer and mathematician Nikolas Copernicus... who came to believe that Earth is not the center of the universe, but revolves around the Sun.

Seven decades after Copernicus, Galileo Galilei used his newly developed telescope to show that our Sun was just one among countless other stars in the universe. 

By the modern era, the "many worlds" view held sway in scientific circles. A variety of thinkers considered what and who inhabited worlds beyond our own. 

From Martians desperate to get off their planet... to alien invaders intent on launching pre-emptive strikes against ours... or simple life forms on an evolutionary track to complexity.

But other thinkers have been struck by a different view.

The Greek philosophers Aristotle and Ptolemy believed that humans and Earth are unique. 

With the spread of Christianity, this Ptolemaic system became widely accepted. 

The latest variation on this theme is what's called the "Rare Earth" hypothesis. It holds that Earth and sophisticated life were the result of fortuitous circumstances that may not be easy to find again in our galaxy. 

Does the current search for planets shed light on this debate... sending it in one direction or the other?

So far, our only good reference for recognizing an Earth-like planet is... Earth. 

It does have some fortuitous characteristics... it's dense, it's rocky -- with a complex make-up of minerals and organic compounds -- and it has lots and lots of water. 

It's also got a nearly circular orbit around the Sun, at a distance that allows liquid water to flow... not too close and not too far away, in the so-called "Habitable Zone." 

That's defined as the range of distance from a parent star that a planet would need to maintain surface temperatures between the freezing and boiling points of water. 

Of course, that depends on the size of the planet, the make-up of its atmosphere, and a host of other factors. 

And whether the parent star is large; medium like the Sun; or small. 

Some scientists also believe we live in a "Galactic Habitable Zone." We're close enough to the galactic center to be infused with heavy elements generated by countless stellar explosions over the eons...

But far enough away from deadly gamma radiation that roars out of the center. 

If there is a galactic habitable zone... it's thought to lie 26,000 light years from the center... about where we are... give or take about 6,000 light years.

The Birth Of A Planet

Astronomers studying a newborn star have caught a detailed glimpse of planets forming around it, revealing a never-before seen stage of planetary evolution.

Large gas giant planets appear to be clearing a gap in the disk of material surrounding the star, and using gravity to channel material across the gap to the interior, helping the star to grow. Theoretical simulations have predicted such bridges between outer and inner portions of disks surrounding stars, but none have been directly observed until now.

An international team of astronomers have used the partially completed Atacama Large Millimeter/submillimeter Array (ALMA) to study a young star about 450 light-years from Earth. They identified two thin filaments of gas streaming from the outer disk to the inner, across a broad gap cut by young planets.

"Currently, the only mechanism known to produce such gap-crossing dense molecular flows, with residual carbon monoxide gas more diffusely spread out inside the gap, is planetary formation," lead scientist Simon Casassus of the University of Chile told SPACE.com in an email.

Bridging The Gap

Far from Earth, the fledgling star HD 142527 is nearing the end of its formation process. Around 2 million years old, the young star is about twice as massive as the sun, though it is still slowly growing. A disk of spinning dust and gas left over from its formation surrounds the star, and from this material, planets are being created. 

As baby planets, or planetesimals, travel through the disk, they absorb the material around them, creating gaps. Such paths have been seen in a number of newborn systems. HD 142527 boasts a gap that starts at a point equivalent to Saturn's position in the solar system and extends outward 14 times as far. The gap, which scientists had previously measured, is so large that several planets would be required to clear it of debris.

Using ALMA to observe the system, Casassus and his team have found that the gap is not completely empty. Two filaments reach from the outer disk to the inner, indicating that at least two young planets exist within the space.

These bridges are important to the continued growth of the system's young sun. The inner disk around the star is too small to sustain its growth; Casassus and his team concluded that the disk around HD 142527 would be depleted within a year without a bridge. Planets funneling material from the outer disk to the inner would help nourish their star.

The process won't continue forever, however.

"Eventually, the proto-gaseous giants will exhaust the material within their radius of influence," Casassus said. "How much material will have infallen, in what timescales, and how this impacts the planet location and eventual migration are all open questions in the field of planet formation. Our observations are a step forward."

Mind The Gap

In addition to revealing the bridges between the two disks, ALMA's detailed measurements showed that the gaps weren't completely empty. Instead, they contain traces of carbon monoxide gas.

"This residual gas was predicted by all dynamical calculations, but previous detections were not as clear-cut and direct as the ALMA result," Casassus said.

The data was taken by ALMA during its first year of observation. The array of 66 telescopes, set up in Chile, is still under construction but should be completed this year, at which point Casassus plans to observe the system in greater detail.

Although the dense gas of the filaments would obstruct a direct view of the young planets, studying the system at the higher resolution of the completed ALMA could reveal knots along the filaments that could signify their location.

At the same time, a more precise examination of the leftover gas in the gaps could help astronomers to narrow down the mass of the developing planets.

The research was published online today (Jan. 2) in the journal Nature.

Via: "Space"

At Least 100 Billion Planets Populate The Galaxy

That's the conclusion of a new study by astronomers at the California Institute of Technology (Caltech) that provides yet more evidence that planetary systems are the cosmic norm. The team made their estimate while analyzing planets orbiting a star called Kepler-32—planets that are representative, they say, of the vast majority in the galaxy and thus serve as a perfect case study for understanding how most planets form.

"There's at least 100 billion planets in the galaxy—just our galaxy," says John Johnson, assistant professor of planetary astronomy at Caltech and coauthor of the study, which was recently accepted for publication in the Astrophysical Journal. "That's mind-boggling."

"It's a staggering number, if you think about it," adds Jonathan Swift, a postdoc at Caltech and lead author of the paper. "Basically there's one of these planets per star."

The planetary system in question, which was detected by the Kepler space telescope, contains five planets. The existence of two of those planets have already been confirmed by other astronomers. The Caltech team confirmed the remaining three, then analyzed the five-planet system and compared it to other systems found by the Kepler mission.

The planets orbit a star that is an M dwarf—a type that accounts for about three-quarters of all stars in the Milky Way. The five planets, which are similar in size to Earth and orbit close to their star, are also typical of the class of planets that the telescope has discovered orbiting other M dwarfs, Swift says. Therefore, the majority of planets in the galaxy probably have characteristics comparable to those of the five planets.

While this particular system may not be unique, what does set it apart is its coincidental orientation: the orbits of the planets lie in a plane that's positioned such that Kepler views the system edge-on. Due to this rare orientation, each planet blocks Kepler -32's starlight as it passes between the star and the Kepler telescope.

By analyzing changes in the star's brightness, the astronomers were able to determine the planets' characteristics, such as their sizes and orbital periods. This orientation therefore provides an opportunity to study the system in great detail—and because the planets represent the vast majority of planets that are thought to populate the galaxy, the team says, the system also can help astronomers better understand planet formation in general.

To do that calculation, the Caltech team determined the probability that an M-dwarf system would provide Kepler-32's edge-on orientation. Combining that probability with the number of planetary systems Kepler is able to detect, the astronomers calculated that there is, on average, one planet for every one of the approximately 100 billion stars in the galaxy. 

But their analysis only considers planets that are in close orbits around M dwarfs—not the outer planets of an M-dwarf system, or those orbiting other kinds of stars. 

As a result, they say, their estimate is conservative. In fact, says Swift, a more accurate estimate that includes data from other analyses could lead to an average of two planets per star.

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 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. The fact that M-dwarf systems vastly outnumber other kinds of systems carries a profound implication, according to Johnson, which is that our solar system is extremely rare. 

The implications of a galaxy chock full of planets are far-reaching, the researchers say. "It's really fundamental from an origins standpoint," says Swift, who notes that because M dwarfs shine mainly in infrared light, the stars are invisible to the naked eye. "Kepler has enabled us to look up at the sky and know that there are more planets out there than stars we can see."

Via: "California Institute Of Technology"

The Drifting Planet

An artist’s rendering of CFBDSIR2149, as viewed through an infrared filter. Image via L. Calçada, P. Delorme, Nick Risinger, R. Saito, European Southern Observatory/VVV Consortium

The astronomy world is abuzz over the discovery of an exoplanet in a nearly unprecedented situation: It’s the first observed to be hurtling through space on its own, rather than orbiting a star. The find, reported by researchers from the University of Montreal in a paper published Wednesday in the journal Astronomy and Astrophysics, is roughly 100 light-years away and has been labelled CFBDSIR2149.

“Although theorists had established the existence of this type of very cold and young planet, one had never been observed until today,” Étienne Artigau, an astrophysicist at the University of Montreal, said in a statement. Over the past decade, astronomers have spotted several candidate objects that could potentially qualify as drifting planets, but the line between what is called a “planet” and what is called a “star” is fuzzy, especially when observing from a distance. Through a telescope, it’s hard to differentiate whether a small solitary object is a “homeless” planet (as the researchers have termed this one) or a brown dwarf, the smallest type of star. The researchers concluded that this is a planet, and one that is 50 to 120 million years old and about 400 degrees Celsius in temperature.

Because this object appears to be traveling through space along with a diffuse group of roughly 30 associated stars called the AB Doradus Moving Group (but does not orbit any of them), the astronomers were able to work out several more pieces of information about it, such as its age, mass and temperature, based on the assumption that the planet likely shares an origin with the rest of the stars in the group. Objects must be less than 13 times the mass of Jupiter to be considered a planet, rather than a brown dwarf, and this object appears to have a mass between four and seven times that of Jupiter, making it an unqualified, starless planet, the first of its kind.

Scientists have speculated that this type of object could result from a normal planet being flung out of its solar system, or could form alone in its present state. Theories of planet and star formation imply that there might be an extremely high number of such solitary planets—they might be as common as normal stars.

For astronomers, the problem is seeing them. Unlike stars, these objects don’t emit a large amount of light. This planet was detected using data from the Canada-France-Hawaii Telescope, located on the summit of Mauna Kea in Hawaii, with further details worked out using the ESO’s Very Large Telescope in northern Chile.

The researchers say that free-floating planets like this one are scientifically significant beyond their apparent uniqueness. “These objects are important, as they can either help us understand more about how planets may be ejected from planetary systems, or how very light objects can arise from the star formation process,” Delorme said. “If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space.”

Via: "Smithsonian Mag"

A Diamond Bigger Than Planet Earth

Forget The Diamond As Big As The Ritz. This One's Bigger Than Planet Earth

Orbiting a star that is visible to the naked eye, astronomers have discovered a planet twice the size of our own made largely out of diamond.

The rocky planet, called '55 Cancri e', orbits a sun-like star in the constellation of Cancer and is moving so fast that a year there lasts a mere 18 hours.

Discovered by a U.S.-Franco research team, its radius is twice that of Earth's but it is much more dense with a mass eight times greater. It is also incredibly hot, with temperatures on its surface reaching 3,900 degrees Fahrenheit (1,648 Celsius).

"The surface of this planet is likely covered in graphite and diamond rather than water and granite," said Nikku Madhusudhan, the Yale researcher whose findings are due to be published in the journal Astrophysical Journal Letters.

The study - with Olivier Mousis at the Institut de Recherche en Astrophysique et Planetologie in Toulouse, France - estimates that at least a third of the planet's mass, the equivalent of about three Earth masses, could be diamond.

"This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth," Madhusudhan said, adding that the discovery of the carbon-rich planet meant distant rocky planets could no longer be assumed to have chemical constituents, interiors, atmospheres, or biologies similar to Earth.

Via: "Reuters"

The Polaris Moon Rover

The Polaris rover is for catching solar rays which shine almost horizontally at the Moon's north pole, a location Polaris is due to explore before 2016. 

Built by Astrobotic Technology, it'll be ferried aboard the SpaceX Falcon 9 rocket to our celestial companion, where it'll drill into the surface in search of ice. 

The company, spun out of the Carnegie Mellon University, hopes to identify resources at a depth of up to four feet that could be used to support manned Moon expeditions in the future. 

The plan is to complete the mission during a 10-day window of sunlight, digging at up to 100 sites over a three-mile stretch. However, if it can live through the harsh two-week-long nights, then it may continue to operate "indefinitely."

NASA is backing the project, providing ice-prospecting gear and money, although Astrobotic hopes to get more cash for its work -- over $20 million from Google's Lunar X Prize. 




Via: "EnGadget"

The Venus Transit

Posted by "CavalierZee"



The Venus transit as seen in the 171 wavelength. This channel is especially good at showing coronal loops - the arcs extending off of the Sun where plasma moves along magnetic field lines. The brightest spots seen here are locations where the magnetic field near the surface is exceptionally strong.

Credit: NASA SDO