By Matt Smith, CNN
The future of NASA's planet-hunting Kepler space observatory was in question Wednesday after a part that helps aim the spacecraft stopped working, the U.S. space agency said.
Controllers found Tuesday that Kepler had gone into a "safe mode" and one of the reaction wheels needed to orient the spacecraft would not spin, Associate NASA Administrator John Grunsfeld told reporters. NASA engineers are trying to figure out whether they can get the balky part back into service or whether they can resume control by another method, Grunsfeld said.
"We're not ready to call the mission over," he said. But at roughly 40 million miles from Earth, "Kepler is not in a place where I can go up and rescue it."
The Kepler mission has identified 132 planets beyond our solar system since its launch in 2009, leading scientists to believe that most stars in our galaxy have planets circling them. It has gone into a "safe mode" with its solar panels facing back at the sun, giving controllers intermittent communication with the craft as it spins.
NASA plans to capture an asteroid and start sending astronauts aloft again by 2017, even with a tighter budget, the U.S. space agency announced Wednesday.
The Obama administration is asking Congress for just over $17.7 billion in 2014, down a little more than 1% from the nearly $17.9 billion currently devoted to space exploration, aeronautics and other science.
The request includes $105 million to boost the study of asteroids, both to reduce the risk of one hitting Earth and to start planning for a mission to "identify, capture, redirect, and sample" a small one. The plan is to send an unmanned probe out to seize the asteroid and tow it into orbit around the moon, where astronauts would study it.
By Matt Smith, CNN
The meteor that exploded over the steppes of southwestern Russia sent a low-frequency rumble bouncing through the Earth, giving scientists new clues about the biggest cosmic intruder in a century.
The big boom over Chelyabinsk on February 15 also produced a wave of sound thousands of times lower than a piano's middle C - far below the range of human hearing, according to the international agency that watches for nuclear bomb tests. The Comprehensive Test Ban Treaty Organization said that sound wave showed up on sensors from Greenland to Antarctica, making it the largest ever detected by its network.
Scientists then used that wave to calculate the size of the small asteroid that plunged to Earth, said Margaret Campbell-Brown, an astronomer at Canada's University of Western Ontario.
By Matt Smith, CNN
It's not the kind of place you'd call home: an airless, rocky planet so close to its sun that some metals will melt on its surface.
But it's a big little discovery for NASA's space observatory Kepler. The space agency says the planet, dubbed Kepler-37b, is the smallest yet found beyond our solar system.
Slightly larger than the moon and about a third the size of Earth, it's one of three planets circling the star Kepler-37, NASA announced Wednesday - and the first of dozens of discovered exoplanets known to be smaller than any that orbit our sun.
The findings were reported in this week's edition of the journal Nature.
NASA put its newest Landsat satellite into orbit on Monday, extending a long-running program that has been beaming back dramatic images of Earth for more than 40 years.
The Landsat Data Continuity Mission - to be designated Landsat 8, once it's up and running - lifted off from California's Vandenberg Air Force Base atop an Atlas V booster.
The $855 million platform, about the size of a sport-utility vehicle, has been in the works for years amid concerns about maintaining the U.S. suite of geoscience satellites.
Space, it has been said, is big. Really big.
But big enough for two companies that want to mine near-Earth asteroids?
A venture announced Tuesday in California hopes so.
Deep Space Industries says it wants to start sending miniature scout probes, dubbed "Fireflies," on one-way missions to near-Earth asteroids as soon as 2015. Larger probes, "Dragonflies," that will bring back 50- to 100-pound samples from prospective targets could be on their way by 2016, company CEO David Gump told reporters.
The SpaceX Dragon capsule remains on course for the International Space Station despite losing one of nine booster engines, but a satellite launched on the same rocket didn't reach its intended orbit, its operator said Monday.
SpaceX launched the first commercial space cargo mission on Sunday night. But a minute and 19 seconds after the Falcon 9 booster lifted off from Cape Canaveral, Florida, one of the nine Merlin engines that power the rocket "lost pressure suddenly," the company disclosed Monday.
The rocket "did exactly what it was designed to do," as its flight computer made adjustments to keep the Dragon headed into the proper orbit. The unmanned capsule, which is carrying about 1,000 pounds of supplies for the space station, is scheduled to arrive at the orbital platform on Wednesday, SpaceX said.
X-ray data from NASA's MESSENGER probe points to high levels of magnesium and sulfur on the surface of the planet Mercury, suggesting its makeup is far different from that of other planets, scientists say.
The unmanned orbiter has been beaming back data from the first planet for a year and a half. Readings from its X-ray spectrometer point to a planet whose northern volcanic plains formed through upwellings of rocks more exotic than those often found on the Earth, the Moon or Mars, said Shoshana Weider, a researcher at the Carnegie Institution of Washington.
"Before this MESSENGER mission, a lot of people assumed it was very like the Moon - it's dark, it's grey," Weider said. But while the Moon's surface formed when light materials floated to the top of an ocean of molten rock, the low level of calcium on Mercury indicates that didn't happen there.
After two space shuttle flights in the 1980s, astronaut Sally Ride spent much of the rest of her life trying to encourage children, particularly girls, to give the sciences a shot.
Ride, the first American woman in space, was part of a wave of women who entered the traditionally male disciplines of natural sciences and engineering in the 1970s. One of those she inspired was Catherine "Cady" Coleman, who told CNN's "Newsroom" that she never considered becoming an astronaut before meeting Ride in 1982.
"When I'd think of what they look like, it's those Mercury Seven standing in front of an airplane, a bunch of guys that were older than me with not as much hair," she said. "And suddenly you meet Sally Ride, and it became clear to me that maybe this is something I can pursue."
Scientists hope to test new samples of Pacific bluefin tuna after low levels of radioactive cesium from Japan's Fukushima Daiichi nuclear accident turned up in fish caught off California in 2011, researchers reported Monday.
The bluefin spawn off Japan, and many migrate across the Pacific Ocean. Tissue samples taken from 15 bluefin caught in August, five months after the meltdowns at Fukushima Daiichi, all contained reactor byproducts cesium-134 and cesium-137 at levels that produced radiation about 3% higher than natural background sources - but well below levels considered dangerous for human consumption, the researchers say.
Cesium-137 has a radioactive half-life of about 30 years, and traces of the isotope still persist from above-ground nuclear bomb tests in the 1950s and '60s. But cesium-134, which has a half-life of only two years, "is inarguably from Fukushima Daiichi," Stanford University marine ecologist Dan Madigan told CNN.