This artist's illustration gives an impression of how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using the microlensing technique concluded that planets around stars are the rule rather than the exception. The average number of planets per star is greater than one.

This means that there is likely to be a minimum of 1,500 planets within just 50 light-years of Earth. The results are based on observations taken over six years by the PLANET (Probing Lensing Anomalies NETwork) collaboration, which was founded in 1995. The study concludes that there are far more Earth-sized planets than bloated Jupiter-sized worlds. This is based on calibrating a planetary mass function that shows the number of planets increases for lower mass worlds. A rough estimate from this survey would point to the existence of more than 10 billion terrestrial planets across our galaxy. The results were published in the Jan. 12, 2012, issue of the British science journal Nature. Image Credit: NASA, ESA, and M. Kornmesser (ESO


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Tea said ...

The below might be old news to some but after watching a moving, unique documentary about space, people and Chile. One fact just took me by surprise.

However as documentaries go Nostalgia of the light, is a must see. A film shot entirely in one of the most arid places in the world where the lack of moisture allows viewers of the night time sky, Astonomers and other star gazers, to opportunity see our galaxy as clearly as if you were in space. Incredible.

I have got to see that documentary. Zero humidity? That is amazing. I wonder how that happens?

It's sad when you see footage like this and then you look up at the city night sky and its pales so much in comparison

^^
I'm sure that's the Atacama desert in Chile,
It was featured in Top Gear where they drove through it.

Also, would love to view the skyline there, we just dont get that site in the city's

From Tea: "This means that there is likely to be a minimum of 1,500 planets within just 50 light-years of Earth. The results are based on observations taken over six years by the PLANET (Probing Lensing Anomalies NETwork) collaboration, which was founded in 1995."

- That's impressive. Now it would be interesting to know what percentage are likely to be earth-like. If we hit light speed (and so far science does seem to indicate it's as fast as we'll go), that's only 2 generations on board some sort of vessel before arrival from our system. You could actually have people born on earth die on another world. An amazing thought.

@ corr - BTW - its not a happy documentary but a good one!

Lurch said ...

From Tea: "This means that there is likely to be a minimum of 1,500 planets within just 50 light-years of Earth. The results are based on observations taken over six years by the PLANET (Probing Lensing Anomalies NETwork) collaboration, which was founded in 1995."

- That's impressive. Now it would be interesting to know what percentage are likely to be earth-like. If we hit light speed (and so far science does seem to indicate it's as fast as we'll go), that's only 2 generations on board some sort of vessel before arrival from our system. You could actually have people born on earth die on another world. An amazing thought.

I reckon the percentage for the amount of Earth-like planets would be pretty high indeed. And that would increase once you take into account the entire universe and not just the Milky Way.

An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes.

The discovery, made by astronomers using data from NASA's Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in X-rays as a million suns radiate at all wavelengths.

Researchers used Chandra to discover a new ultraluminous X-ray source, or ULX. These objects give off more X-rays than most binary systems, in which a companion star orbits the remains of a collapsed star. These collapsed stars form either a dense core called a neutron star or a black hole. The extra X-ray emission suggests ULXs contain black holes that might be much more massive than the ones found elsewhere in our galaxy.

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Supermassive black holes, weighing millions to billions times more than the sun, lurk in the centers of most galaxies. These hefty monsters lay quietly until an unsuspecting victim, such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches.

Astronomers have spotted these stellar homicides before, but this is the first time they identified the victim. Using several ground- and space-based telescopes, a team of astronomers led by Suvi Gezari of the Johns Hopkins University in Baltimore identified the victim as a star rich in helium gas. The star resides in a galaxy 2.7 billion light-years away. The team's results will appear in today's online edition of the journal Nature.

"When the star is ripped apart by the gravitational forces of the black hole, some part of the star's remains falls into the black hole while the rest is ejected at high speeds," Gezari said. "We are seeing the glow from the stellar gas falling into the black hole over time. We're also witnessing the spectral signature of the ejected gas, which we find to be mostly helium. It is like we are gathering evidence from a crime scene. Because there is very little hydrogen and mostly helium in the gas, we detect from the carnage that the slaughtered star had to have been the helium-rich core of a stripped star."

This observation yields insights about the harsh environment around black holes and the types of stars swirling around them. It is not the first time the unlucky star had a brush with the behemoth black hole.

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BTW the little black dot on the top left hand corner is the black hole ripping apart a star

That is amazing. Just think of the forces needed to destory a star that is probably billions of years old.

Black holes are caused when stars collapse in on themselves, creating a miniscule object with super-massive density. The gravitational force of a black hole is so powerful that not even light can escape its grasp, in fact light even gets warped as its pulled.

Remember to keep an eye out on the moon this weekend (the 6th for South Africa).

Perigee "Super Moon" On May 5-6



May 2, 2012: The full Moon has a reputation for trouble. It raises high tides, it makes dogs howl, it wakes you up in the middle of the night with beams of moonlight stealing through drapes. If a moonbeam wakes you up on the night of May 5th, 2012, you might want to get out of bed and take a look. This May’s full Moon is a "super Moon,” as much as 14% bigger and 30% brighter than other full Moons of 2012.

The scientific term for the phenomenon is "perigee moon." Full Moons vary in size because of the oval shape of the Moon's orbit. The Moon follows an elliptical path around Earth with one side ("perigee") about 50,000 km closer than the other ("apogee"). Full Moons that occur on the perigee side of the Moon's orbit seem extra big and bright.

Such is the case on May 5th at 11:34 pm Eastern Daylight Time1 when the Moon reaches perigee. Only one minute later, the Moon will line up with Earth and the sun to become brilliantly full. The timing is almost perfect.

Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other.

The best time to look is when the Moon is near the horizon. For reasons not fully understood by astronomers or psychologists, low-hanging Moons look unnaturally large when they beam through trees, buildings and other foreground objects. On May 5th, this Moon illusion will amplify a full Moon that's extra-big to begin with. The swollen orb rising in the east at sunset should seem super indeed.

Folklore holds that all kinds of wacky things happen under the light of a full Moon. Supposedly, hospital admissions increase, the crime rate ticks upward, and people behave strangely. The idea that the full Moon causes mental disorders was widespread in the Middle Ages. Even the word "lunacy," meaning "insanity," comes from the Latin word for "Moon."

The majority of modern studies, however, show no correlation between the phase of the Moon and the incidence of crime, sickness, or human behavior. The truth is, the Moon is less influential than folklore would have us believe.

It's true that a perigee full Moon brings with it extra-high "perigean tides," but according to the National Oceanic and Atmospheric Administration this is nothing to worry about. In most places, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)--not exactly a great flood.

Super perigee Moons are actually fairly common. The Moon becomes full within a few hours of its closest approach to Earth about once a year on average. The last such coincidence occurred on March 19th, 2011, producing a full Moon that was almost 400 km closer than this one. As usual, no trouble was reported--unless you count a midnight awakening as trouble.

If so, close the drapes on May 5th. Otherwise, enjoy the super-moonlight.

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Great now I can go on that murder spree and blame it on the moon! !bm

PASADENA, Calif. – NASA's Spitzer Space Telescope has detected light emanating from a "super-Earth" planet beyond our solar system for the first time. While the planet is not habitable, the detection is a historic step toward the eventual search for signs of life on other planets.

"Spitzer has amazed us yet again," said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. "The spacecraft is pioneering the study of atmospheres of distant planets and paving the way for NASA's upcoming James Webb Space Telescope to apply a similar technique on potentially habitable planets."

The planet, called 55 Cancri e, falls into a class of planets termed super Earths, which are more massive than our home world but lighter than giant planets like Neptune. The planet is about twice as big and eight times as massive as Earth. It orbits a bright star, called 55 Cancri, in a mere 18 hours.

Previously, Spitzer and other telescopes were able to study the planet by analyzing how the light from 55 Cancri changed as the planet passed in front of the star. In the new study, Spitzer measured how much infrared light comes from the planet itself. The results reveal the planet is likely dark, and its sun-facing side is more than 2,000 Kelvin (3,140 degrees Fahrenheit), hot enough to melt metal.

The new information is consistent with a prior theory that 55 Cancri e is a water world: a rocky core surrounded by a layer of water in a "supercritical" state where it is both liquid and gas, and topped by a blanket of steam. "It could be very similar to Neptune, if you pulled Neptune in toward our sun and watched its atmosphere boil away," said Michaël Gillon of Université de Liège in Belgium, principal investigator of the research, which appears in the Astrophysical Journal. The lead author is Brice-Olivier Demory of the Massachusetts Institute of Technology in Cambridge.

The 55 Cancri system is relatively close to Earth, at 41 light-years away. It has five planets, with 55 Cancri e the closest to the star and tidally locked, so one side always faces the star. Spitzer discovered the sun-facing side is extremely hot, indicating the planet probably does not have a substantial atmosphere to carry the sun's heat to the unlit side.

NASA's James Webb Space Telescope, scheduled to launch in 2018, likely will be able to learn even more about the planet's composition. The telescope might be able to use a similar infrared method to Spitzer to search other potentially habitable planets for signs of molecules possibly related to life.

"When we conceived of Spitzer more than 40 years ago, exoplanets hadn't even been discovered," said Michael Werner, Spitzer project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Because Spitzer was built very well, it's been able to adapt to this new field and make historic advances such as this."

In 2005, Spitzer became the first telescope to detect light from a planet beyond our solar system. To the surprise of many, the observatory saw the infrared light of a "hot Jupiter," a gaseous planet much larger than the solid 55 Cancri e. Since then, other telescopes, including NASA's Hubble and Kepler space telescopes, have performed similar feats with gas giants using the same method.

In this method, a telescope gazes at a star as a planet circles behind it. When the planet disappears from view, the light from the star system dips ever so slightly, but enough that astronomers can determine how much light came from the planet itself. This information reveals the temperature of a planet, and, in some cases, its atmospheric components. Most other current planet-hunting methods obtain indirect measurements of a planet by observing its effects on the star.

During Spitzer's ongoing extended mission, steps were taken to enhance its unique ability to see exoplanets, including 55 Cancri e. Those steps, which included changing the cycling of a heater and using an instrument in a new way, led to improvements in how precisely the telescope points at targets.

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology (Caltech) in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

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@Tea

Could you please supply a link to this, please?

Updated - with link - BTW you should check out NASA's Spitzer section - Amazing stuff and they recently announced continuation of the spitzer project

Awesome, Thanks Tea!!

Also - if you guys get a chance - Watch this -

http://apod.nasa.gov/apod/ap120508.html

Interesting stuff!

So the Kepler and Spitzer telescopes are simalar in how they detect planets just that Spitzer uses Infrared light?

Seems so