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“While this approximately 400-meter sized asteroid has a three-year orbital period around the sun and returns to the Earth’s neighborhood periodically, it does not represent a threat because its orbital path does not pass sufficiently close to the Earth’s orbit … Any statements about risk for impact of discovered asteroids and comets should be verified by scientists and the media by accessing NASA’s Near Earth Object (NEO) program web site.”

About 35 million years ago an asteroid about 5 to 8 kilometers in diameter, travelling at a speed of about 15 to 20 kilometers per second slammed into the area that is now known as the Tamyr Peninsula of northern Siberia, Russia. [1] The energy delivered by this hypervelocity impact was powerful enough to instantly melt thousands of cubic kilometers of rock and blast millions of metric tons of ejecta high into the air. Some of that ejecta landed on other continents. The explosion produced a 100 kilometer-wide impact crater with a rim of deformed rock up to 20 kilometers...

Asteroids and comets have a few things in common. They are both celestial bodies orbiting our Sun, and they both can have unusual orbits, sometimes straying close to Earth or the other planets. They are both “leftovers” — made from materials from the formation of our Solar System 4.5 billion years ago. But there are a few notable differences between these two objects, as well. The biggest difference between comets and asteroids, however, is what they are made of. While asteroids consist of metals and rocky material, comets are made up of ice, dust, rocky materials and organic compounds. When...

The comet 67P/Churyumov-Gerasimenko may actually be two objects stitched together. New images from ESA's Rosetta spacecraft show an odd constriction near the middle of the comet, suggesting that two clumps of matter may have merged in what scientists call a contact binary. The conclusions are preliminary, as Rosetta was still roughly 12,000 kilometers away from the comet when the images were taken. The comet could also have had a more regular single shape with parts carved out through impacts or ice melting as the object circled the sun, mission scientists say. They will have more details about the comet's...

In April, we reported that Ceres and Vesta, the largest and brightest asteroids respectively, were speeding through Virgo in tandem. Since then both have faded, but the best is yet to come. Converging closer by the day, on July 5, the two will make rare close pass of each other when they’ll be separated by just 10 minutes of arc or the thickness of a fat crescent moon. ... Both asteroids are still within range of ordinary 35mm and larger binoculars; Vesta is easy at magnitude +7 while Ceres still manages a respectable +8.3. From an outer suburban or rural...

Don't worry, NASA's known about it for ages. Like, four whole days. So here’s a fun fact: while you were sleeping last night, you had a near-death experience. Yes, you – and everyone else on this lovely planet. In the wee hours of the morning, a pretty sizeable asteroid soared by the Earth, just missing it. But we’re okay. For now. At 4:13am EDT, asteroid 2014 HL129 essentially side-swiped the Earth, coming within 186,000 miles of our planet. For reference, the moon is 238,855 miles away. Which means the asteroid was much, much closer to us than the moon will...

Chelyabinsk, a large city in western Russia, was best known for producing tractors and professional hockey players until the morning of February 15, 2013, when a 19-meter-wide meteor screamed through the sky and exploded with the force of 500 kilotons of TNT. The meteor generated a fireball many times brighter than the sun, so powerful it even caused sunburns. The shock wave blew out windows and knocked residents off of their feet, injuring more than 1,200. The object was the largest to strike Earth in more than a century... Asteroids that come within 28 million miles of our planet are...

Less than four months after getting switched back on — and only days after its “next light” images — NASA’s re-commissioned NEOWISE mission has made its first discovery: a never-before-seen near-Earth asteroid 27 million miles (43 million km) away. Identified in a series of images captured on Dec. 29, 2013 YP139 is a coal-black asteroid about 650 meters — over 2,100 feet — wide. The image above shows the asteroid as a circled red dot as it moved across NEOWISE’s field of view over a period of several hours. 2013 YP139 would be all but invisible in optical light because...

Video of Engine Test Using traditional chemical rockets, a trip to Mars – at quickest — lasts 6 months. But a new rocket tested successfully last week could potentially cut down travel time to the Red Planet to just 39 days. The Ad Astra Rocket Company tested a plasma rocket called the VASIMR VX-200 engine, which ran at 201 kilowatts in a vacuum chamber, passing the 200-kilowatt mark for the first time. "It's the most powerful plasma rocket in the world right now," says Franklin Chang-Diaz, former NASA astronaut and CEO of Ad Astra. The company has also signed...

Monday, January 20, at 10:00 GMT (which is 5:00 a.m. for U.S. East Coasters like me) the wake-up call will ring on ESA’s Rosetta spacecraft, bringing it out of hibernation after over two and a half years in preparation of its upcoming and highly-anticipated rendezvous with a comet. The wake-up will incite the warming of Rosetta’s star trackers, which allow it to determine its orientation in space. Six hours later its thrusters will fire to stop its slow rotation and ensure that its solar arrays are receiving the right amount of sunlight. ... After nearly a decade of soaring through...

Herschel used its far-infrared vision with the HIFI instrument to see a clear spectral signature of the water vapor. But, interestingly, Herschel did not see water vapor every time it looked. There were variations in the water signal during the dwarf planet’s 9-hour rotation period. The telescope spied water vapor four different times, on one occasion there was no signature. The astronomers deduced that almost all of the water vapor was seen to be coming from just two spots on the surface. Although Herschel was not able to make a resolved image of Ceres, the team was able to derive...

“I have announced this star as a comet, but since it is not accompanied by any nebulosity and, further, since its movement is so slow and rather uniform, it has occurred to me several times that it might be something better than a comet. But I have been careful not to advance this supposition to the public.” -Giuseppe Piazzi, discoverer of Ceres, the first Asteroid Out beyond Mars, but not quite out as far as Jupiter, a collection of thousands of rocky objects, ranging in size from pebbles all the way up to the size of Texas, lies the...

The asteroid Vesta may be the brightest asteroid in the solar system, but it remains shrouded in mystery. When NASA's Dawn probe enters into orbit around Vesta on July 15 — the first spacecraft to visit the 330-mile-wide (530-kilometer) protoplanet — it promises to shed light on the many enigmas of the second-largest body in the asteroid belt. NASA launched the $466 million Dawn mission in 2007, with Vesta as the first (but not last) stop. The Dawn probe is also expected to visit Ceres, the largest asteroid in the solar system, but only after unlocking the secrets of Vesta....

If you were riding with NASA’s Dawn spacecraft, now cruising the asteroid belt between Mars and Jupiter, you would see a brightening new point of light against the starry background. This is Vesta, your immediate destination. Artist rendition of Dawn gathering spectral data from Vesta. Scientists have estimated that Dawn will enter Vesta’s gravitational field on July 16, 2011, and begin taking data when it descends to an altitude of 2700 km from the surface. Dawn’s first image of Vesta, the second-largest object in the asteroid belt, still has fewer pixels than those of it taken by the Hubble Space...

This image shows the first, unprocessed image obtained by NASA's Dawn spacecraft of the giant asteroid Vesta in front of a background of stars. It was obtained by Dawn's framing camera on May 3, 2011, from a distance of about 750,000 miles (1.2 million kilometers). CREDIT: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Crater patterns on Vesta and Ceres could help pinpoint when Jupiter began to form during the evolution of the early Solar System. A study modelling the cratering history of the largest two objects in the asteroid belt, which are believed to be among the oldest in the Solar System, indicates that the type and distribution of craters would show marked changes at different stages of Jupiter’s development. Results will be presented by Dr Diego Turrini at the European Planetary Science Congress in Potsdam, Germany, on Monday 14 September. The study, carried out by scientists at the Italian National Institute for...

Astronauts, space buffs and an unimpressed public hunger for space exploration that's more dramatic, more heroic, more new. Something like, say, landing astronauts on a distant rock hurtling through space at 15 miles per second. That's exactly the kind of trip NASA has been studying. In fact, scientists at the space agency recently determined that a manned mission to a near-Earth asteroid would be possible using technology being developed today... This wouldn't be our first trip to an asteroid. We've been visiting them by proxy for years now, using unmanned space probes. In 2000 NASA's NEAR Shoemaker spacecraft arrived at...

I'm mainly posting this because the liftoff image is one of the most impressive I've seen.

A NASA probe blasted into space early Thursday, kicking off an unprecedented mission to explore the two largest asteroids in the solar system. Riding atop a Delta 2 rocket, NASA's Dawn spacecraft launched toward the asteroids Vesta and Ceres at 7:34 a.m. EDT (1134 GMT) from Cape Canaveral Air Force Station in Cape Canaveral, Fla. "In my view, we're going to be visiting some of the last unexplored worlds in the solar system," said Marc Rayman, Dawn director of system engineering at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. Dawn's eight-year mission will carry the 2,685-pound (1,212-kilogram) probe across...

CAPE CANAVERAL, Fla. - NASA is about to embark on an unprecedented asteroid-belt mission with a spacecraft aptly named Dawn. The 3 billion-mile, eight-year journey to probe the earliest stages of the solar system will begin with liftoff, planned for just after sunrise Thursday. Rain is forecast, however, and could force a delay. Scientists have been waiting for Dawn to rise since July, when the mission was put off because of the more pressing need to launch NASA's latest Mars lander, the Phoenix. Once Phoenix rocketed away in August, that cleared the way for Dawn. "For the people in the...