Planet's
1 view | +0 today
Follow
Your new post is loading...
Your new post is loading...
Scooped by Mani Neptune
Scoop.it!

3 Years of Hunting Planets | Planet Hunters.

3 Years of Hunting Planets | Planet Hunters. | Planet's | Scoop.it

Congratulations everyone! Today is our third birthday. Three years ago we weren’t sure if would even find Planets, today we have lots of candidates and even some confirmed Planets of our very own. Here’s a poster to celebrate: the Planet Hunters avatar made up of the almost-200,000 names of our registered users. Happy Birthday everyone!

more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

"The Great Dying" --MIT Insights into the Most Severe Mass Extinction in Earth’s History.

"The Great Dying" --MIT Insights into the Most Severe Mass Extinction in Earth’s History. | Planet's | Scoop.it
 
        
 
It was the greatest exinction event of all time (at least by Earth standards): Since the first organisms appeared on Earth approximately 3.8 billion years ago, life on the planet has had some close calls.
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

Blue Alien Planet Has Molten Glass Rain & Unusual Atmosphere, New ... - Huffington Post

Blue Alien Planet Has Molten Glass Rain & Unusual Atmosphere, New ... - Huffington Post | Planet's | Scoop.it
Toronto Star
Blue Alien Planet Has Molten Glass Rain & Unusual Atmosphere, New ...
Huffington Post
There's a "blue marble" alien planet just 63 light-years from Earth, but the world is anything but friendly to life.
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

NASA's 'Curiosity' Discovers Solar Eclipse Up Red Planet - French Tribune

NASA's 'Curiosity' Discovers Solar Eclipse Up Red Planet - French Tribune | Planet's | Scoop.it
French Tribune
NASA's 'Curiosity' Discovers Solar Eclipse Up Red Planet
French Tribune
If compared to these moons, the Galilean moons of Titan of Saturn, Jupiter, Uranus and Neptune in the family of the Sun are bigger.
more...
No comment yet.
Rescooped by Mani Neptune from Amazing Science
Scoop.it!

Planet with four suns discovered, by volunteers

Planet with four suns discovered, by volunteers | Planet's | Scoop.it
Astronomers discover a planet - about six times bigger than Earth - whose skies are lit by four different suns, some 5,000 light-years away.

 

The distant world orbits one pair of stars which have a second stellar pair revolving around them. The discovery was made by volunteers using the Planethunters.org website along with a team from UK and US institutes; follow-up observations were made with the Keck Observatory. The planet has been named PH1 after the Planet Hunters site. It is thought to be a "gas giant" slightly larger than Neptune - more than six times the radius of the Earth.


Via Dr. Stefan Gruenwald
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

Weather on the Outer Planets Only Goes So Deep

Weather on the Outer Planets Only Goes So Deep | Planet's | Scoop.it
Weizmann Institute researchers and their colleagues set an upper limit for the thickness of jet streams on Uranus and Neptune
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

Giant Alien Planet Discovered in Most Distant Orbit Ever Seen - Space.com

Giant Alien Planet Discovered in Most Distant Orbit Ever Seen - Space.com | Planet's | Scoop.it
Space.com
Giant Alien Planet Discovered in Most Distant Orbit Ever Seen
Space.com
The planet is more than 20 times farther away from its star than Neptune is from the sun. Credit: Vanessa Bailey. View full size image.
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

Oldest minerals from Mars found on Earth.

Oldest minerals from Mars found on Earth. | Planet's | Scoop.it
A meteorite recently retrieved from the Sahara Desert bears the oldest known minerals ever seen from the planet Mars, say scientists in the US, Australia and France. These minerals are 4.4 billion years old and therefore formed just 150 million years after the red planet's birth. Their age confirms earlier indications that the Martian crust formed quickly, as did the crusts of the Earth and Moon. Today, Mars is a cold, dry, nearly airless desert, but ancient Mars was warmer and wetter, and may even have given rise to life. The planet had a thicker atmosphere then and dried-up riverbeds – signs of a milder climate – course through parts of the planet's oldest terrain, highlands that blanket most of the southern hemisphere. Scientists know that the highlands are ancient because these regions bear the most craters. Although NASA has tried to land eight spacecraft on Mars – and succeeded seven times – these landers were not able to measure the ages of rocks nor determine all the chemical elements that constitute them. Scientists therefore value Martian meteorites that they can scrutinize in the laboratory – rocks with isotopic compositions that reveal they came from Mars. Unfortunately, with only one previous exception, all the other Martian meteorites are so young that they originated long after the climate deteriorated. First-ever rock from the highlands "It is very exciting that we have the first-ever sample to come from the Martian highlands," says Munir Humayun, a geochemist at Florida State University in Tallahassee. He and his colleagues studied a Martian meteorite named NWA 7533. It was one of five stones that landed together in northwest Africa, which is what NWA stands for. The meteorite is a so-called breccia, a collage of different rock fragments. Breccias can form after an asteroid hits a planet and throws up chunks of rock that later conglomerate. These impact breccias litter the cratered highlands of the Moon and presumably Mars. But breccias can also arise after violent volcanic eruptions. Which type of breccia is NWA 7533 – impact or volcanic? "When we got this meteorite, we looked inside the breccia for clues as to impact," Humayun says. The search focused on siderophiles, which are "iron-loving" elements. These are rare in a planet's crust because they sink with iron into the core but are common in asteroids. Sure enough, the meteorite abounded with siderophiles such as nickel and iridium, indicating it was an impact breccia – and therefore probably came from the heavily cratered highlands. "So we thought, 'Wow! This looks like a highland breccia'," Humayun says. If so, it had to be old. Zircons remember But science is rarely that simple, and this interpretation conflicted with a report earlier this year by other researchers who found that another Martian stone – which fell with NWA 7533 – was too young to have come from the ancient cratered highlands. Fortunately, NWA 7533 contains tough minerals called zircons. "From a geochronological point of view, zircons are like elephants: they remember," says Humayun. "They are resistant to almost anything." Even impacts do not destroy them. Moreover, zircon crystals trap uranium, which decays into lead, allowing scientists to date them. With one exception, every zircon in the meteorite had the same age – 4.4 billion years. Humayun's reaction? "Like, eureka!" "This is a really exciting find," says Harry McSween of the University of Tennessee at Knoxville, a planetary scientist unaffiliated with the research team. "It is a much more representative sample of the ancient crust of Mars than we have seen before [among meteorites]," he says. "The zircon method is the best method there is for defining the age of crystallization of a magma, so I'm real confident in this 4.4-billion-year age." Only one other Martian meteorite is ancient. In 1996 scientists claimed that a meteorite named ALH 84001 harboured fossils of Martian life. The meteorite was then thought to be 4.5 billion years old, but like the fossils themselves, that figure has not held up to further scrutiny. Later work lowered the age to 4.1 billion years. Therefore, the 4.4-billion-year-old zircons in the new meteorite are the oldest known minerals from Mars. Fast-forming crust As the meteorite is a breccia, the zircons came from different rocks throughout the Martian crust, yet all but one have the same old age. That means the crust formed fast, says Humayun. Otherwise, the zircons would have a spread of ages. In addition, the zircons are as old as the earliest zircons on the Earth and Moon, so all three worlds created their crusts at the same time. Although the new meteorite's zircons are ancient, the rock itself may be younger. The scientists do not know when the various fragments cemented together to assemble the breccia. The meteorite contains soil with a composition that nearly matches what NASA's Spirit rover saw at Gusev Crater. Unlike modern Martian soil, however, the meteoritic soil lacks much sulphur or chlorine – probably because flowing water on a warmer, wetter world carried these elements away. The scientists publish their work today in Nature. About the author Ken Croswell is a US-based astronomer and the author of Magnificent Mars
more...
No comment yet.
Scooped by Mani Neptune
Scoop.it!

Learn about the stars and planets with Ian Ridpath tonight - On The Wight

Learn about the stars and planets with Ian Ridpath tonight - On The Wight | Planet's | Scoop.it
Island Echo
Learn about the stars and planets with Ian Ridpath tonight
On The Wight
...
more...
No comment yet.
Rescooped by Mani Neptune from Amazing Science
Scoop.it!

At Least One in Six Stars in Our Galaxy Has an Earth-sized Planet

At Least One in Six Stars in Our Galaxy Has an Earth-sized Planet | Planet's | Scoop.it

The quest for a twin Earth is heating up. Using NASA's Kepler spacecraft, astronomers are beginning to find Earth-sized planets orbiting distant stars. A new analysis of Kepler data shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury. Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there.

 

Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics (CfA), presented the analysis today in a press conference at a meeting of the American Astronomical Society in Long Beach, Ca. A paper detailing the research has been accepted for publication in The Astrophysical Journal.

 

Kepler detects planetary candidates using the transit method, watching for a planet to cross its star and create a mini-eclipse that dims the star slightly. The first 16 months of the survey identified about 2,400 candidates. Astronomers then asked, how many of those signals are real, and how many planets did Kepler miss?

 

By simulating the Kepler survey, Fressin and his colleagues were able to correct both the impurity and the incompleteness of this list of candidates to recover the true occurrence of planets orbiting other stars, down to the size of Earth.

 

"There is a list of astrophysical configurations that can mimic planet signals, but altogether, they can only account for one-tenth of the huge number of Kepler candidates. All the other signals are bona-fide planets," says Fressin.

Most sun-like stars have planets.

 

Altogether, the researchers found that 50 percent of stars have a planet of Earth-size or larger in a close orbit. By adding larger planets, which have been detected in wider orbits up to the orbital distance of the Earth, this number reaches 70 percent.

 

Extrapolating from Kepler's currently ongoing observations and results from other detection techniques, it looks like practically all Sun-like stars have planets.

 

The team then grouped planets into five different sizes. They found that 17 percent of stars have a planet 0.8 - 1.25 times the size of Earth in an orbit of 85 days or less. About one-fourth of stars have a super-Earth (1.25 - 2 times the size of Earth) in an orbit of 150 days or less. (Larger planets can be detected at greater distances more easily.) The same fraction of stars has a mini-Neptune (2 - 4 times Earth) in orbits up to 250 days long.

 

Larger planets are much less common. Only about 3 percent of stars have a large Neptune (4 - 6 times Earth), and only 5 percent of stars have a gas giant (6 - 22 times Earth) in an orbit of 400 days or less.


Via Dr. Stefan Gruenwald
more...
John Barnett's comment, March 16, 2013 9:06 AM
Seems we often like to reinterpret for what we are hoping for ... even in science, which is a more dangerous area to mislead. The title here implies it's more likely to find an earth-like planet. The details on the article indicate differently - most all the earth-sized planets are too close to their sun, the larger planets are much closer than in our solar system as well, and any the size of our multi-purpose protector Jupiter is very, very rare from what I read here. Jupiter appears to allow for our farther orbit from the sun and protects us from the majority of space missiles (large comets and asteroids). Our earth is in an extremely rare sweet spot that has the balance to allow for more advanced life. (Hope all this moves us all to value and preserve it properly all the more!)
Rescooped by Mani Neptune from Amazing Science
Scoop.it!

Research model suggests moons of some planets developed from rings

Research model suggests moons of some planets developed from rings | Planet's | Scoop.it

French researchers Sébastien Charnoz and Aurélien Crida have proposed in a paper published in the journal Science that moons that orbit some of the planets in our solar system came about due to accretion from material in rings that used to surround the planets, rather than as entities that took shape while their host planets were forming.

 

Space researchers have long proposed that moons circulating planets generally came to exist in one of three ways: as entities that formed on their own as their host was developing, as clumps that coalesced from material shed from a planet struck by some other body, or by being captured as they passed by. In this new research, Charnoz and Crida propose a fourth possibility – that the moons were formed from material in rings that surrounded their host planet.

In attempting to explain how moons orbiting planets such as Uranus, Neptune and Pluto, came about, the researchers created mathematical models that could predict moon formation from material surrounding a planet. Their models suggest that when material in a ring reaches a certain critical point at some distance from the host, called the Roche radius, the gravity from the host planet is offset by the gravitational pull that each piece exerts on others in the ring. Because of this, material in the ring begins to coalesce with some pieces eventually accreting enough material to form a moon. They add that the speed at which material in the ring orbits the host may account for the number of moons that form. Slow moving material might result in the formation of several small moons, while fast moving material may result in just one, as might have been the case with Earth and its single moon. Their model explains, they suggest, why all of the moons orbiting planets (except for Jupiter) in our solar system grow in size as they orbit farther from the host planet. Jupiter they say, is an exception, with its moons likely originating in tandem with the planet birth itself. The researchers concede that their models can't explain how the rings themselves came to exist, but suggest it's possible that they came about due to collisions with other bodies moving through space.

 


Via Dr. Stefan Gruenwald
more...
No comment yet.