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A unique “double asteroid” was photographed by a powerful telescope as it whizzed by Earth last month at over 43,000 mph. The asteroid, classified as 1999 KW4, is made up of two components — a larger body orbited by a smaller one separated by about 1.6 miles. It got as close as 3.2 million miles to Earth on May 25 — about 14 times the distance from Earth to the Moon, the European Southern Observatory (ESO) said in a news release Monday. The double asteroid, which has an orbit well known to scientists, is not an impact threat to Earth,...

Gravitational waves are caused by calamitous events in the Universe. Neutron stars that finally merge after circling each other for a long time can create them, and so can two black holes that collide with each other. But sometimes there's a burst of gravitational waves that doesn't have a clear cause. One such burst was detected by LIGO/VIRGO on January 14, and it came from the same region of sky that hosts the star Betelgeuse. Yeah, Betelgeuse, aka Alpha Orionis. The star that has been exhibiting some dimming behaviour recently, and is expected to go supernova at some point in...

Earth's gravitational wave observatories -- which hunt for ripples in the fabric of space-time -- just picked up something weird. The Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo detectors recorded an unknown or unanticipated "burst" of gravitational waves on Jan. 14. The gravitational waves we've detected so far usually relate to extreme cosmic events, like two black holes colliding or neutron stars finally merging after being caught in a death spiral. Burst gravitational waves have not been detected before and scientists hypothesize they may be linked to phenomena such as supernova or gamma ray bursts, producing a tiny "pop" when...

Making lemonade from lemons, two teams of physicists have used data from misguided satellites to put Albert Einstein’s theory of gravity, the general theory of relativity, to an unexpected test. The opportunistic experiment confirms to unprecedented precision a key prediction of the theory—that time ticks slower near a massive body like Earth than it does farther away. As Einstein explained, gravity arises because massive bodies warp space-time. Free-falling objects follow the straightest possible paths in that curved space-time, which to us appear as the parabolic arc of a thrown ball or the circular or elliptical orbit of a satellite. As...

GPS has a new job. It does a great job of telling us our location, but the network of hyper-accurate clocks in space could get a fix on something far more elusive: dark matter. Dark matter makes up 80 per cent of the universe's matter but scarcely interacts with ordinary matter. A novel particle is the most popular candidate, but Andrei Derevianko at the University of Nevada, Reno, and Maxim Pospelov at the Perimeter Institute in Waterloo, Ontario, Canada propose that kinks or cracks in the quantum fields that permeate the universe could be the culprit. If they are right,...

Martin Bizzarro of the University of Copenhagen and his colleagues set out to determine the amount of iron in the early solar system. To do so, they measured nickel-60, a decay product of iron-60, in eight meteorites known to have formed at different times during the first 3 million years of the solar system. The meteorites that formed more than about a million years after the start of the solar system contain significantly more nickel-60 than do those that formed earlier, the team found. In a neighborhood of young stars, only a supernova could have produced iron-60, the parent of...

Asteroid Vesta: The 10th Planet? Discovery Brightens Odds of Finding Another Pluto Nemesis: The Million Dollar Question HOUSTON, TEXAS -- Our solar system may have had a fifth terrestrial planet, one that was swallowed up by the Sun. But before it was destroyed, the now missing-in-action world made a mess of things. Space scientists John Chambers and Jack Lissauer of NASA's Ames Research Center hypothesize that along with Mercury, Venus, Earth, and Mars -- the terrestrial, rocky planets -- there was a fifth terrestrial world, likely just outside of Mars's orbit and before the inner asteroid belt. Moreover, Planet V...

A FIFTH terrestrial planet may once have orbited between Mars and Jupiter. Although gravitational disturbances would have sent the planet hurtling into the sun or out into space long ago, traces of this long-gone world may still be visible in part of the asteroid belt today. Recent simulations have suggested that the gas giants of our solar system formed with circular orbits but moved into their more elongated paths about 4 billion years ago – 700 million years after the solar system formed. While the gas giants were in circular orbits, rocky planets should have formed in stable orbits out...

Late yesterday, NASA turned the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California towards Asteroid 1998 QE2 as it was heading towards its closest approach to Earth, and they got a big surprise: the asteroid is a binary system. 1998 QE2 itself is 1.7 miles (2.7 kilometers) in diameter, and the newly found orbiting moon is about 600 meters in diameter. The radar images were taken were taken on May 29, 2013, when the asteroid was about 3.75 million miles (6 million kilometers) from Earth. “Radar really helps to pin down the orbit of an asteroid as well as...

SCIENTISTS have captured the moment a giant solar flare from a distant star scorched one of its orbiting planets, blasting the upper atmosphere away. NASA's Swift Telescope detected a huge X-ray flare from the star 63 light years from Earth and then the Hubble recorded the pictures as it ripped into an orbiting gas giant known as "HD 189733b". While the planet managed to survive the experience, scientists calculated it received three million times as many X-rays as Earth receives during a solar flare. At least 900 tonnes of gas was ejected from the planet's atmosphere per second at a...

Proposed by British scientists as a joint effort of NASA and the European Space Agency, the mission would offer the first close-up view of Uranus in 25 years.British space scientists are leading plans to send a probe to explore giant ice planet Uranus. They have put forward a detailed proposal to the European Space Agency to launch a joint mission with NASA to the distant world, 1.8 billion miles from the sun. It would give scientists their first close-up views of Uranus since NASA’s Voyager 2 flew past and captured fleeting pictures 25 years ago. The £400million mission is designed...

The Geminid meteor shower, which peaks each year in December... are *not* caused by debris left behind from an active comet... Until recently, the favored view of Phaethon was that it's a dead comet -- the rocky core of a "dirty snowball" that lost its ices after too many close encounters with the sun. ... In June 2009 astronomers using the STEREO sun-watching probe suddenly saw the rocky body flare to life as it neared the sun, brightening by a factor of two... So, not so dead after all. But that brings us back to figuring out what exactly Phaethon...

It's a classic image from every youngster's science textbook: a cutaway image of Earth's interior. The brown crust is paper-thin; the warm mantle orange, the seething liquid of the outer core yellow, and at the center the core, a ball of solid, red-hot iron. Now a new theory aims to rewrite it all by proposing the seemingly impossible: Earth has not one but two inner cores. The idea stems from an ancient, cataclysmic collision that scientists believe occurred when a Mars-sized object hit Earth about 4.45 billion years ago. The young Earth was still so hot that it was mostly...

Deep down, the moon may be more like Earth than scientists ever thought. A new moon-rock study suggests the satellite has an iron core... The moon's core could be a clue to its ancient origins, which have long puzzled astronomers. "Our moon is too big to be a moon," Taylor said. "It's huge compared to the moons we see around other planets, so it has always been suspected that there was something strange in its origin." ...Rock samples from NASA's Apollo 15 and Apollo 17 moon missions of the early 1970s have now shed more light on the moon's origins,...

Ten years ago, NASA researchers discovered that the Pioneer 10 and 11 spacecraft had fallen slightly behind course during their 35-year journeys to the outer reaches of the solar system. In what has become known as the Pioneer anomaly, which was the subject of one of the talks this weekend at the American Physical Society here in St. Louis, nobody knows for sure why it happened. It probably stemmed from leaking gas or heat. But there's also the possibility, however remote, that gravity doesn't behave the way we expect. Until recently, researchers haven't had the data to distinguish the different...

"It turns out that there are a significant number of asteroids that aren't just a single object, but two and even on occasion three in orbit around one another," Pollock said. He and his colleagues record information related to changes in amount of light reflected from asteroids. Sometimes this indicates the existence of a pair of asteroids that are revolving around each other... "When a single, irregularly shaped asteroid spins, the amount of reflective area changes and it appears to change brightness," Pollock said. "When you have two rotating asteroids revolving around one another, the brightness changes are much more...

The new role that quantum information plays in gravity sets the scene for a dramatic unification of ideas in physics One of the hottest new ideas in physics is that gravity is an emergent phenomena; that it somehow arises from the complex interaction of simpler things. A few month's ago, Erik Verlinde at the the University of Amsterdam put forward one such idea which has taken the world of physics by storm. Verlinde suggested that gravity is merely a manifestation of entropy in the Universe. His idea is based on the second law of thermodynamics, that entropy always increases over...

(PhysOrg.com) -- A new theory suggests the Moon was formed after a natural nuclear explosion in the Earth's mantle rather than after the impact of a massive object with the Earth, as previously thought. The problem with the impact hypothesis is that simulations calculate the Moon should be composed of 80% impactor and 20% Earth, whereas in fact the isotope ratios of light and heavy elements found in Moon rocks so far examined are virtually identical to those on Earth. The fission hypothesis is an alternative explanation for the formation of the moon, and it predicts similar isotope ratios in...