As the count of known planets in distant star systems continues to grow (the number now exceeds 400), so too does the number of ways we have to learn about them. Reporting in Nature this week, a team of astronomers say they have measured the makeup of an exoplanet‘s atmosphere using an Earth-based telescope for the first time.
Mark Swain’s team directed NASA’s Infrared Telescope Facility toward HD 189733 b, a planet 63 light years away, discovered back in 2005. HD 189733 b was already known from space-borne observations to harbor several specific molecules in its atmosphere: water, methane, carbon dioxide and carbon monoxide [Scientific American]. Swain’s analysis confirmed those previous findings using spectrography, in which the light from an object is broken down into its component wavelengths, allowing the identification of atoms or molecules by their unique emission or absorption properties [Scientific American]. Swain’s team also turned up something else—a spike in emissions at a very particular wavelength of light, 3.3 microns, that the earlier observations didn’t detect and that Swain’s team can’t explain–at least not yet.
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How on Earth did the moon come into being? If you subscribe to the latest theory, the moon was born out of a nuclear explosion on Earth that sent a chunk of mass flying from the planet’s core into orbit, where it finally became the moon. But cool as that sounds, some killjoy scientists are pooh-poohing the hypothesis, calling it “unnecessary,” “nonsensical,” and “not physically sensible.”
The standard theory of the moon’s origin holds that a giant space object, possibly an asteroid, banged into Earth and sent a large piece of the planet flying into space. That piece eventually became the moon. But the composition of the moon doesn’t seem to support this theory. Researchers say if an asteroid or some such object smashed away part of the Earth, the Moon ought to be composed of about 80 percent of that object’s constituent material and about 20 percent of the Earth’s. But the makeup of moon rock closely mirrors that of the Earth [Popular Science].
An alternate theory, known as the fission theory, suggests that the moon spun out of the rapidly spinning blob of molten rock that would later become Earth [Popular Science]. But no one has been able to explain what caused a huge chunk of earth to spin away and become the moon. Now, researchers Rob de Meijer and Wim van Westrenem have proposed in an online paper that centrifugal forces may have concentrated heavy, radioactive elements like uranium and thorium at the boundary between the Earth’s mantle and its core. Then, they propose, a massive nuclear explosion occurred at the edge of Earth’s core, flinging red-hot, liquid rock into space. The orbiting detritus gradually congealed into what is now our planet’s lone satellite [Discovery News].
Such “georeactors” have existed on Earth before, albeit on a smaller scale than these researchers propose. But de Meijer and van Westrenem have gotten little support for their hypothesis, and plenty of scorn.
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A few days after the White House released its budget that proposes axing NASA’s Constellation program and providing more support to private space flight, the Obama administration began to follow through on the second part of that equation. NASA has announced that it’s giving $50 million to five companies to support new space vehicles.
That $50 million isn’t from the revised budget, but rather the American Reinvestment and Recovery Act (or in more common parlance, the $787 billion federal stimulus package). Nevertheless, NASA chief Charles Bolden said these five companies–Sierra Nevada Corporation, Blue Origin, Boeing, Paragon Space Development Corp., and United Launch Alliance–would play a large part in future plans. “Ladies and gentlemen, these are the faces of the new frontier. The vanguard,” said Bolden. “We will certainly be adding to this group in the near future” [Space.com].
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While astronomers continue to learn about peculiar phenomena in distant galaxies, our own sun’s behavior still presents a mystery. So NASA’s next mission, the Solar Dynamics Observatory, will watch every move the sun makes in the hope of fully figuring out its cycles of sunspots, solar flares, and other activity.
Set to launch next week aboard an Atlas V rocket, the SDO will snap 60 high-resolution images of the sun every minute. Using three specific science instruments, SDO will measure how much extreme ultraviolet light the Sun emits, map plasma flows in the Sun, map the surface of its magnetic field, and image the solar atmosphere [Astronomy]. Scientists hope this huge catalog of images, taken at a resolution far better than that of HDTV and measuring about 1.5 terabytes of data per day, will help them connect the flares and spots on the solar surface to what’s happening down below, inside the star.
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The Obama administration’s new budget may come in at a hulking $3.8 trillion, but one thing it doesn’t include is continued funding for the Constellation program. The program, which was intended to continue the work of the aging space shuttles, will get the ax if Congress approves the President’s plan. This also means that NASA would abandon its goal of returning to the moon by 2020.
Obama’s budget ends work on the shuttle follow-on vehicle, known as Orion, as well as a pair of rockets developed to fly astronauts to the space station, the moon and other destinations in the solar system. “We are proposing canceling the program, not delaying it,” Peter Orszag, director of the Office of Management and Budget, told reporters [Reuters]. The announcement had been some time in coming: The Augustine panel that Obama convened last year to review human spaceflight concluded that Constellation couldn’t succeed without $3 billion in additional annual funding, and rumors broke out last week that the President’s budget would kill the program for good.
In place of the Constellation program’s Ares rockets and Orion crew capsule, Obama’s plan calls for funneling money to private companies that are jockeying for NASA contracts. The Washington Post reports that the plan would funnel $6 billion to support private space companies developing a vehicle to ferry astronauts back and forth from the International Space Station. Companies expected to seek the new space taxi business include United Launch Alliance, a partnership between Boeing and Lockheed Martin that launches rockets for theUnited States Air Force, and Space Exploration Technologies, a start-up company led by Elon Musk, who founded PayPal [ The New York Times]. The plan would also extend the life of the space station until 2020.
Commercial Spaceflight Federation president Bretton Alexander was understandably giddy at the prospect of private companies taking center stage. “At a time when job creation is the top priority for our nation, a commercial crew programme will create more jobs per dollar because it leverages millions in private investment and taps the potential of systems that serve both government and private customers,” he said [BBC News].
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NASA is sending a radar-equipped jet to conduct flights over Haiti and the Dominican Republic to capture 3-D images that could help predict future earthquakes. An estimated 170,000 people were killed in the 7.0 earthquake that battered Haiti on January 12. Unfortunately, experts predict more quakes as the country is situated in a seismically volatile zone.
A Gulfstream III jet is now on its way to map Haiti and the Dominican Republic, the two nations that share the island of Hispaniola. The Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, was originally on its way to Central America to study volcanoes, forests, and Mayan ruins, but on its way south it will now also study Hispaniola’s fault lines.
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While Jupiter’s two largest moons, Ganymede and Callisto, are nearly the same size, they’re far from identical twins. Now, in a Nature Geoscience study, Amy Barr and her team might have figured out this tale of two similar moons with very different histories.
Voyager and Galileo mission images showed Ganymede, seen here on the right, to be a geologically active place, with a surface that scientists think changes through tectonic processes like those that we have here on the Earth. Callisto, seen on the left, looks totally different: Its rock and ice have not mixed in the same way, and it doesn’t seem to have such active geology, despite being approximately the same size as Ganymede. For 30 years, researchers have wondered what process could have got enough heat into Ganymede to drive its geological evolution without setting off Callisto as well [ScienceNOW Daily News].
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If you’ve been expecting to hear from a far-off alien civilization, don’t hold your breath, suggests Frank Drake, the founder of Search for Extraterrestrial Intelligence (SETI)–the odds of ET phoning Earth may be diminishing. And your digital TV might well be to blame.
Speaking at a meeting of the Royal Society in London, Drake said that digital transmissions are effectively “gagging” the planet. In the fast-fading analog age, TV and radio signals transmitted around the world escaped into space. At present, the Earth is surrounded by a 50 light year-wide ”shell” of radiation from analogue TV, radio and radar transmissions, he said [The Telegraph]. Those signals reach distant stars, which means that if someone is home at any of those stars, they could heard us.
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After ten months of trying to extricate the Mars rover Spirit from a sandy patch on the Red Planet, NASA has finally given up. The space agency said Tuesday that Spirit will no longer be a fully mobile robot, roving over an alien planet. It will instead be a stationary science platform–which means a sedentary life for the robot geologist [that] has taken thousands of images and found evidence in Mars’ rocks of a wetter, warmer past [BBC].
Ten months ago, as Spirit was driving south beside the western edge of a low plateau called Home Plate, its wheels broke through a crusty surface and churned into soft sand hidden underneath [NASA]. The rover has been stuck there ever since, and now only four of its six wheels are functioning. Since all the maneuvers that the NASA instructed the rover to try have failed to free it, the sandpit known as “Troy” will be Spirit’s final resting place.
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Are you ready for some free fall?
Austrian daredevil Felix Baumgartner officially announced that sometime this year, he intends to jump from a balloon at a height of nearly 23 miles, breaking the 50-year-old world record for the highest parachute jump held by retired U.S. Air Force pilot Joe Kittinger. Kittinger is the Stratos mission’s capcom (short for capsule communicator), which means that he will be the voice in Baumgartner’s helmet. Kittinger’s advice to his successor: “Have fun, enjoy it, and tell us all about it when you get down” [Scientific American].
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Both Uranus and Neptune have quirky magnetic poles—they’re located about 60 degrees off the geographic pole rather than very nearby, like ours is. The reason, researchers suggest in a new Nature Physics study, could be that oceans of diamond—yes, oceans of diamond—cover our solar system’s two most distant planets.
The diamond idea isn’t a new one, but it’s a terribly hard question to study because you have to get diamond to melt in the lab to study it, and this experiment was the first to document the pressure and temperature at which that happens. The mineral is notoriously hard, of course, but there’s something more: Diamond doesn’t like to stay diamond when it gets hot. When diamond is heated to extreme temperatures it physically changes, from diamond to graphite. The graphite, and not the diamond, then melts into a liquid. The trick for the scientists was to heat the diamond up while simultaneously stopping it from transforming into graphite [Discovery News].
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America seems to be more and more linked to Asia–not just by complicated financial ties, but also by currents of air pollution that are boosting smog levels in American skies. For years scientists wondered why some rural areas in the western United States had high levels of ozone, when the areas had very little industry or automobile traffic. The answer, apparently, was blowing in the wind.
A new study, published in Nature reveals that springtime ozone levels in western North America are on the rise, because of air pollution coming in from south and east Asia.
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Once, most of exoplanets that astronomers spotted were giants, but now they’re seeing more and more new planets with masses not far off from the Earth’s. One of those newly found Earth-like exoplanets, however, may not have always been so similar to our own world: An astronomer made the case last week that the small, sweltering planet was once a mighty gas giant that shrank.
Astronomers discovered Corot-7b in September. Its diameter is roughly 1.7 times that of Earth. Based on its size and mass, its density is similar to Earth’s, indicating that it is a rocky Earth-like orb [ABC News]. But the comparisons end there. While it’s rocky like Earth, this fiery hellhole is no place for life. It orbits its star at a distance of only 1.6 million miles (we’re presently at a much more comfortable 93 million miles from our sun) and completes a revolution in only 20 hours’ time. And, NASA’s Brian Jackson argued at last week’s American Astronomical Society meeting, Corot-7b is probably just a shell of its former self, and once was a type of gas giant called a “hot Jupiter.”
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On January 7, 1610, Galileo Galilei pointed his “spyglass” to the heavens and stared up at Jupiter, one of the brightest lights in the evening sky, and noted what he at first assumed to be three bright stars near the planet. But over the following nights, he realized that those three bright bodies weren’t fixed in the heavens like stars, but rather seemed to dance around Jupiter along with a fourth, smaller body.
Galileo triumphantly announced his discovery of four “planets” that revolved around Jupiter in his March treatise, Starry Messenger [pdf]. Thinking of his pocketbook, he dutifully proposed naming them the Medicean Stars in honor of his patron, Cosimo de Medici. But the name didn’t stick, and today we honor the scientist rather than the patron by calling Jupiter’s four largest satellites the Galilean moons.
The discovery dealt a death blow to the Ptolemaic understanding of the universe, in which all planets and stars were believed to orbit the Earth. For, as Galileo wrote in his treatise, “our own eyes show us four stars which wander around Jupiter as does the moon around the earth.”
In the 400 years that have passed since Galileo first laid eyes on them, we’ve learned a great deal about the moons Io, Europa, Ganymede, and Callisto (all named after the mythological paramours of Jupiter). If all goes according to plan we’ll soon get to know them much more intimately–NASA and the European Space Agency are currently planning missions to closely observe three of the moons. Click though this gallery to view NASA’s most stunning photos of the four satellites, and to find out what we’ve discovered in the four centuries since Galileo began the work.
(For more on Galileo’s discovery and what it meant to science, check out this post from DISCOVER’s Phil Plait.)
Image: NASA/JPL/DLR
Back in December 1995, the Hubble Space Telescope created the now-famous “deep field” image, which took more than 300 exposures over the course of 10 days to peer deep into the history of the universe and spot more than 1,500 galaxies. A decade and a half later—after failures, upgrades, and the “ultra deep field“—Hubble marches on. Yesterday at the American Astronomical Society meeting, astronomers announced they’d used the telescope to look deeper into the past than ever before.
The new image captures 7,500 galaxies of all kinds and shapes. The oldest galaxies in the image glow an intense blue, indicating high concentrations of the lighter elements hydrogen and helium. Hydrogen fusion inside active stars creates heavier elements such as iron and nickel, which get spread across the universe when massive stars explode. These elements cause modern galaxies to glow in a rainbow of colors, so the extreme blueness of the newfound galaxies suggests that they formed before very many massive stars had lived and died [National Geographic News].
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