Artist’s concept of the pulsar and its planet. The system could fit into our Sun, represented by the yellow surface.
What’s the News: An international team of astronomers has found an exotic planet possibly made of diamond, located about 4,000 light-years away from Earth. The researchers believe that the unusual planet was once a sun-like star, transformed into its current state by its hungry stellar companion, a millisecond pulsar.
What’s the News: Based on early Kepler data, astronomers say that the Milky Way galaxy may house at least two billion Earth-like planets—one for every several dozen sun-like stars. As NASA researcher Joseph Catanzarite told Space.com, “With that large a number, there’s a good chance life and maybe even intelligent life might exist on some of those planets. And that’s just our galaxy alone — there are 50 billion other galaxies.” But while 2 billion sounds like a lot, it’s actually far below many scientists’ expectation; Catanzarite says his teams’ findings actually show that Earth-like planets are “relatively scarce.”
How the Heck:
What’s the Context:
Not So Fast:
Next Up: The astronomers plan on calculating an even more accurate number once all of Kepler’s data is in.
Reference: Joseph Catanzarite and Michael Shao. “The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars.” arXiv:1103.1443v1 Image: Kepler/NASA
The Kepler space telescope, launched nearly two years ago, has already proven its worth as an exoplanet hunter many times over. But the discoveries keep on coming. NASA just announced that Kepler has found its first rocky planet–and that the rocky world is only 1.4 times the size of Earth, making it the smallest exoplanet ever found.
Phil Plait explains that this nearly Earth-sized isn’t actually Earth-like and habitable:
[I]t orbits extremely close in to its star, circling over the star’s surface at a distance of roughly 3 million kilometers (1.8 million miles) — amazingly, it takes less than an Earth day to make one circuit. But being that close to a star comes at a price: the surface temperature of the planet must be several thousand degrees!
The planet, Kepler-10b, may not be habitable to life as we know it, but Plait is still plenty excited. Get the rest of the story on how the planet was found and what its discovery means over at Bad Astronomy.
80beats: Astronomers Predict a Bonanza of Earth-Sized Exoplanets
80beats: How Excited Should We Be About the New “Goldilocks” Exoplanet?
80beats: Astronomers Find a Bevy of Exoplanets; Won’t Discuss Most Interesting Ones
80beats: After a Flawless Launch, Kepler Telescope Gets Ready for Planet Hunting
DISCOVER: How Long Until We Find a Second Earth?
It’s the size of Jupiter, orbits at about the distance of Mercury, and isn’t too far from the temperature range of Earth. Meet Corot-9b, the newest find in the cavalcade of exoplanets and the one its discoverers say is most like the worlds of our own solar system.
“Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium,” said team member Tristan Guillot of the Côte d’Azure Observatory in Nice, France. “And it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures” [Space.com]. The large group of astronomers reporting the find in Nature estimate the planet’s temperature at a range between just below zero and slightly above 300 degrees Fahrenheit. It completes an orbit in 95 days, though it’s about 1,500 light years away.
Mix one part science fiction, one part misunderstood Mayan history, one part Hollywood movie hype, and quite a bit of public credulity, and what do you get? A new wave of doomsday hysteria that is causing scientists to step forward to reassure the public that the world is not, actually, going to end on December 21, 2012.
The rumors flying around the Internet offer a number of ways in which the world may end, including a planetary collision and changes to the Earth’s rotation or magnetic field, but they all agree on that date of doom. You can bet that the viral marketing campaign promoting the upcoming planetary disaster movie 2012 has a little something to do with the recent uptick in paranoia.
“Two years ago, I got a question a week about it,” said NASA scientist David Morrison, who hosts a website called Ask an Astrobiologist. “Now I’m getting a dozen a day. Two teenagers said they didn’t want to see the end of the world so they were thinking of ending their lives” [Los Angeles Times]. In response, Morrison put together a list [pdf] of 10 frequently asked questions about the potential for apocalypse, and refuted them one by one. The clamor has grown so loud that Morrison coined a new word to describe the phenomenon: “cosmophobia,” a fear of the cosmos.
Planets, planets, everywhere! Astronomers have announced the discovery of 32 new planets orbiting distant stars, bringing the list of known exoplanets up to more than 400. The batch of freshly discovered worlds include four that are only five or six times the mass of Earth, an encouraging sign in the quest for a truly Earth-like world that could support life. Researcher Stephane Udry says the discovery is exciting because it suggests that low-mass planets could be numerous in our galaxy. “From [our] results, we know now that at least 40% of solar-type stars have low-mass planets. This is really important because it means that low-mass planets are everywhere, basically” [BBC News].
The discovery was made with the HARPS telescope at the European Southern Observatory‘s facility in Chile. HARPS uses the so-called wobble method to detect planets, in which researchers look for the slight quiver in a star’s regular movements that indicates the gravitational tug of an orbiting planet.
Planets were found around a surprising variety of star types. Gas giant planets were found orbiting “metal-poor” stars — those lacking in elements other than hydrogen and helium — which until now had been considered unlikely places for planets to form [Washington Post]. Researchers also located four exoplanets around relatively cool, small stars known as M-class red dwarfs, and will continue to examine such stars for signs of Earth-like planets. The team expects to keep spotting planets by the dozen, says Udry: “Nature doesn’t like a vacuum so if there is space to put a planet it will put a planet there” [Reuters].
80beats: Study: Strange Planet Has Atmosphere of Gaseous Rock—and It Rains Pebbles
80beats: Rock Solid Evidence of a Rocky, Earth-like Exoplanet
80beats: New Telescope Could Reveal a Milky Way Packed With Habitable Planets
DISCOVER: How Long Until We Find a Second Earth?
Image: European Southern Observatory. Artist’s impression of a newly discovered planet orbiting the star Gliese 667 C, which is part of a triple star system.
In a star system 330 light years away from Earth, astronomers have spotted a giant planet that booms around its parent star in tight, fast circles, completing an orbit (the planet’s “year”) in less than one Earth day. The exoplanet, known as Wasp-18b, is so close to its star that researchers say it appears to be spiraling inwards to its fiery doom. But the odds of seeing a planet in its death throes are so low that researchers are searching for alternate explanations, and say the planet could force scientists to rethink established ideas about planetary forces known as tidal interactions [National Geographic News].
The planet is known as a “hot Jupiter,” meaning that it’s a massive gas giant like our own solar system’s Jupiter, but it orbits in close proximity to its star. Current theories say that such a massive planet so close to its star should be pulling on the host star, creating a tidal effect similar to the moon’s pull on Earth. At that range the planet’s pull would be so strong that it would drain energy from its orbit, causing the planet to rapidly fall into the star [National Geographic News]. But if that’s the case, the planet would meet its death in less than a million years. Since the star system is thought to be about 1 billion years old, the odds of catching the planet in its last stages are one in a thousand.
Scientists have spied a new exoplanet–and not only is it the biggest one yet, but it’s also moving the wrong direction. Unlike other planets, which orbit the same way their stars rotate, WASP-17 moves the opposite way, according to a study published in Astrophysical Journal.
Planets are born from the same ball of rotating gas that creates their parent star, which is why they usually orbit — and spin — in the same direction as their star. While WASP-17 is the first planet known to orbit backwards, some planets in our own solar system, such as Venus, are spinning backwards [Wired]. WASP-17’s backwards motion is known by astronomers as a retrograde orbit.
NASA’s Kepler spacecraft has only been in operation for 10 days, but it’s already spotted a planet, according to a report in Science. That leaves experts optimistic about the craft’s potential to find other Earth-like planets.
Scientists already knew that the planet Kepler found existed. It’s called HAT-P-7b, and it’s a planetary body that’s too heavy and too hot to support life. Still, Kepler gave scientists new details about the planet, including that the planet has a hazy, ozone-like atmosphere. The analysis proves that Kepler’s onboard telescope and light-detecting instruments are at least 100 times more precise than the ground-based detectors that originally found HAT-P-7b [L.A. Times], because Earth-based telescopes must wrestle with distortion from the atmosphere, while Kepler only looks through the clear near-vacuum of space.
Scientists say that Kepler’s capabilities should be sufficient to find Earth-like planets in the “habitable zone” of a star system–that is, the ring where temperatures climb high enough to allow liquid water to exist, but aren’t so scorching as to burn up the surface of the planet.
Only 20 years ago, astronomers were arguing over whether a colleague had discovered the first exoplanet–a planet beyond our solar system that is in orbit around an alien sun. Fast forward to the present day, and researchers have now spotted more than 300 exoplanets in our Milky Way galaxy, and the new topic of discussion is whether a group of astronomers has detected the first extragalactic planet in the Andromeda galaxy.
A new study to be published in the Monthly Notices of the Royal Astronomical Society explains that it should be possible to identify extragalactic planets with the technique of gravitational microlensing, in which a distant source star is briefly magnified by the gravity of an object passing in front of it. This technique has already found several planets in our galaxy, out to distances of thousands of light years. Extending the method from thousands to millions of light years won’t be easy, says [study coauthor] Philippe Jetzer, … but it should be possible [New Scientist]. In fact, it may have already been accomplished.