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Small Asteroid Gives Earth a Close Shave in Highly Anticipated Flyby

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A small asteroid buzzed Earth early Thursday (Oct. 12) in a close flyby that scientists had been looking forward to for months.

The space rock, known as 2012 TC4, zoomed about 26,000 miles (42,000 kilometers) above Antarctica at 1:42 a.m. EDT (0542 GMT) Thursday. That’s about 11 percent the distance between Earth and the moon, and just beyond the orbit of geostationary satellites.

There was never any danger of an impact during this flyby, NASA researchers stressed. And 2012 TC4 is almost certainly too small to cause any serious concern, even if it did line up Earth in its crosshairs. (Before the flyby, scientists estimated the asteroid’s diameter to be between 33 feet and 50 feet, or 10 to 15 meters.) [Famous  Asteroid Flybys and Close Calls (Infographic)]

“The impact effects would be simply a flash through the atmosphere and a breakup — a very bright fireball, basically,” Paul Chodas, manager of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory in Pasadena, California, told Space.com. 

Artist’s illustration showing the small asteroid 2012 TC4 zooming by Earth on Oct. 12, 2017.

Credit: NASA/JPL-Caltech

But Chodas and other asteroid researchers around the world were keenly interested in the flyby nonetheless. They’ve been tracking 2012 TC4 for months, as a sort of dry run for dealing with an approaching asteroid that may indeed pose a threat to Earth.

“This campaign is a team effort that involves more than a dozen observatories, universities and labs around the globe so we can collectively learn the strengths and limitations of our near-Earth object observation capabilities,” campaign leader Vishnu Reddy, an assistant professor at the University of Arizona’s Lunar and Planetary Laboratory, said in a statement.

“This effort will exercise the entire system, to include the initial and follow-up observations, precise orbit determination and international communications,” Reddy added.

Diagram showing the asteroid 2012 TC4's flyby of Earth on Oct. 12, 2017.

Diagram showing the asteroid 2012 TC4’s flyby of Earth on Oct. 12, 2017.

Credit: NASA/JPL-Caltech

Among the telescopes that were involved is the big radar dish at NASA’s Goldstone Deep Space Communications Complex in the California desert, whose observations should help scientists nail down 2012 TC4’s size, Chodas said. (The Arecibo Observatory in Puerto Rico also would have been participating, he added, but it’s been offline since Hurricane Maria pounded the island.)

But don’t expect great radar images of the asteroid, as Goldstone and Arecibo have generated for other, much larger asteroids; 2012 TC4 is likely too small for any significant surface features to be resolved by radar, Chodas said.

Other scopes were slated to gather composition data during the flyby — information that should shed light on the space rock’s density, Chodas said. And scientists should have a good idea of 2012 TC4’s precise orbit in the aftermath of the encounter as well, he added.

As its name suggests, 2012 TC4 was discovered in 2012, by the Panoramic Survey Telescope & Rapid Response System in Hawaii. The asteroid flew past Earth that year — oddly enough, also on Oct. 12.

But the space rock dropped off the map shortly after that 2012 flyby, speeding beyond telescopes’ reach into the dark depths of the solar system. And now astronomers have welcomed it back with open arms.

Thursday’s flyby “was rather special in the sense that we don’t often know about small asteroids approaching the Earth years in advance,” Chodas said.

“It’s interesting to study such a small object, but it’s also very appropriate, because we’re more likely to see a small asteroid heading for Earth impact than a large one, simply because there are far more small ones than large ones,” he added.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

Space.com is the premier source of space exploration, innovation and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier. We transport our visitors across the solar system and beyond through accessible, comprehensive coverage of the latest news and discoveries. For us, exploring space is as much about the journey as it is the destination. So from skywatching guides and stunning photos of the night sky to rocket launches and breaking news of robotic probes visiting other planets, at Space.com you’ll find something amazing every day.

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'Stargate Origins' Brings Classic Sci-Fi Back Tonight

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Mars Meteorite Will Return to the Red Planet with NASA Rover

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Rohit Bhartia of NASA’s Mars 2020 mission holds a slice of a meteorite scientists have determined came from Mars. This slice will likely be used here on Earth for testing a laser instrument for NASA’s Mars 2020 rover; a separate slice will go to Mars on the rover.

A chunk of rock that was once part of Mars, but landed on Earth as a meteorite, will return to the Red Planet aboard a NASA rover set to launch in 2020

The meteorite, known as Sayh al Uhaymir 008 (SaU008) was found in Oman in 1999, but geologists determined that it likely originated on Mars, according to a statement from NASA’s Jet Propulsion Laboratory. Scientists think collisions between Mars and other large bodies in the solar system’s early days sent chunks of the Red Planet into space, where they might wander for eons before falling onto Earth’s surface.  

Now, NASA scientists are using the meteorite to calibrate an instrument that will fly on the Mars 2020 rover, which is scheduled to drop down on the Red Planet’s surface and collect rock samples that could one day be returned to Earth. One of the rover’s main goals is to evaluate the potential habitability of ancient and present-day Mars. [How NASA’s Mars 2020 Rover Will Work (Infographic)]

The meteorite is being used to calibrate an instrument called the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals), which will use techniques often used in forensic science to identify chemicals in the Martian rock samples, in features as thin as a human hair.

A close-up of a meteorite that likely came from Mars.

A close-up of a meteorite that likely came from Mars.

Credit: NASA/JPL-Caltech

The researchers will study the meteorite on Earth, where they are able to make sure their instruments are producing a correct analysis of the rock, and understand what features of the rock are perceptible to their instruments. When the rover settles onto Mars, researchers can once again use the rock to make sure their instruments are working as they should be, before pointing them at features of the Martian surface. 

“We’re studying things on such a fine scale that slight misalignments, caused by changes in temperature or even the rover settling into sand, can require us to correct our aim,” said Luther Beegle, principal investigator for SHERLOC, in the statement. “By studying how the instrument sees a fixed target, we can understand how it will see a piece of the Martian surface.”

There are only about 200 confirmed Martian meteorites that have been found on Earth, according to the statement. The SaU008 meteorite comes from London’s Natural History Museum, which lends out hundreds of meteorites (most of them not from Mars) every year for scientific studies. The SHERLOC team needed a Martian meteorite that was robust enough to endure the journey to Mars without flaking or crumbling. (Launch from Earth and entry into the Martian atmosphere are both very strenuous events for everything on board.) The rock also “needed to possess certain chemical features to test SHERLOC’s sensitivity. These had to be reasonably easy to detect repeatedly for the calibration target to be useful,” according to the statement.  

A slice of a Martian meteorite undergoes oxygen cleaning to remove organics. This slice will remain on Earth to be used for testing and calibrating instruments.

A slice of a Martian meteorite undergoes oxygen cleaning to remove organics. This slice will remain on Earth to be used for testing and calibrating instruments.

Credit: NASA/JPL-Caltech

Usually, instruments like SHERLOC are calibrated with a variety of materials including rock, metal and glass. And Mars meteorites have been used for instrument calibration in the past. In fact, another instrument aboard the Mars 2020 rover, called SuperCam, will be adding a Mars meteorite to NASA’s calibration target, according to the statement. And while this would be the first Mars meteorite to return to the surface of the Red Planet, NASA’s Mars Global Surveyor, which orbits the Red Planet, carries a chunk of a Martian meteorite.

SHERLOC will carry other materials from Earth in addition to Su008, including materials that could be used to make a spacesuit for use on Mars. Observations of how the material withstands the radiation, atmosphere and temperature variations on Mars will provide valuable information for possible crewed trips to the Red Planet.  

“The SHERLOC instrument is a valuable opportunity to prepare for human spaceflight as well as to perform fundamental scientific investigations of the Martian surface,” Marc Fries, a SHERLOC co-investigator and curator of extraterrestrial materials at Johnson Space Center, said in the statement. “It gives us a convenient way to test material that will keep future astronauts safe when they get to Mars.”

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

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Kepler Space Telescope Discovers 95 More Alien Planets

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Planets around other stars are the rule rather than the exception, and there are likely hundreds of billions of exoplanets in the Milky Way alone. NASA’s Kepler space telescope has found more than 2,400 alien worlds, including a new haul of 95 planets announced on Feb. 15, 2018.

The exoplanet discoveries by NASA’s Kepler space telescope keep rolling in.

Astronomers poring through data gathered during Kepler’s current extended mission, known as K2, have spotted 95 more alien planets, a new study reports. 

That brings the K2 tally to 292, and the total haul over Kepler’s entire operational life to nearly 2,440 — about two-thirds of all the alien worlds ever discovered. And more than 2,000 additional Kepler candidates await confirmation by follow-up observations or analysis. [7 Greatest Exoplanet Discoveries by NASA’s Kepler (So Far)]

Kepler launched in March 2009, on a mission to help scientists determine just how common rocky, potentially habitable worlds such as Earth are throughout the Milky Way. For four years, the spacecraft stared continuously at about 150,000 stars, looking for tiny dips in their brightness caused by the passage of planets across their faces.

This work was highly productive, as noted above. But in May 2013, the second of Kepler’s four orientation-maintaining “reaction wheels” failed, and the spacecraft lost its superprecise pointing ability, bringing the original mission to a close.

But mission managers figured out a way to stabilize Kepler using sunlight pressure, and the spacecraft soon embarked on its K2 mission, which involves exoplanet hunting on a more limited basis, as well as observing comets and asteroids in our own solar system, supernovas and a range of other objects and phenomena.

For the new study, researchers analyzed K2 data going all the way back to 2014, zeroing in on 275 “candidate” signals.

“We found that some of the signals were caused by multiple star systems or noise from the spacecraft,” study lead author Andrew Mayo, a Ph.D. student at the Technical University of Denmark’s National Space Institute, said in a statement. “But we also detected planets that range from sub-Earth-sized to the size of Jupiter and larger.”

Indeed, 149 of the signals turned out to be caused by bona fide exoplanets, 95 of which are new discoveries. And one of the new ones is a record setter.

“We validated a planet on a 10-day orbit around a star called HD 212657, which is now the brightest star found by either the Kepler or K2 missions to host a validated planet,” Mayo said. “Planets around bright stars are important because astronomers can learn a lot about them from ground-based observatories.”

The new study was published today (Feb. 15) in The Astronomical Journal.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

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Russian Cargo Ship Delivers 3 Tons of Supplies to Space Station

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