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Hawaiian Telescope Discovers Ten Thousandth Near-Earth Object

English: Asteroid Toutatis from Paranal

English: Asteroid Toutatis from Paranal (Photo credit: Wikipedia)

 

Timelapse of Asteroid 2004 FH's flyby (NASA/JP...

Timelapse of Asteroid 2004 FH’s flyby (NASA/JPL Public Domain) 2004 FH is the centre dot being followed by the sequence; the object that flashes by near the end is an artificial satellite. Images obtained by Stefano Sposetti, Switzerland on March 18, 2004. Animation made Raoul Behrend, Geneva Observatory, Switzerland. (Photo credit: Wikipedia)

 

 

NASA said the 10,000th near-Earth object (NEO) has been discovered using the Pan-STARRS-1 telescope in Hawaii.

 

Astronomers spotted asteroid 2013 MZ5 on the night of June 18, marking a significant milestone for the NEO search. The space agency said 90 percent of all NEOs discovered were first detected by NASA-supported surveys.

 

“But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth,” said Lindley Johnson, program executive for NASA’s Near-Earth Object Observations Program at NASA Headquarters, Washington.

 

In order to be classified as an NEO, a comet or asteroid must approach Earth at an orbital distance to within about 28 million miles. They range in size from as small as a few feet to as large as 25 miles for the largest NEO. Asteroid 2013 MZ5 is about 1,000 feet across and will never be close enough to Earth to be considered potentially hazardous.

 

“The first near-Earth object was discovered in 1898,” said Don Yeomans, long-time manager of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “Over the next hundred years, only about 500 had been found. But then, with the advent of NASA’s NEO Observations program in 1998, we’ve been racking them up ever since. And with new, more capable systems coming on line, we are learning even more about where the NEOs are currently in our solar system, and where they will be in the future.”

 

About 10 percent of the 10,000 NEOs discovered are larger than six-tenths of a mile, which is roughly the size that could produce global consequences if one struck Earth. However, NASA says its program has found that none of these larger NEOs currently pose an impact threat.

 

NASA said scientists predict there to be about 15,000 NEOs that are one-and-a-half football fields in size, or 480 feet. There could be more than a million NEOs that are about one-third of a football field in size. An NEO hitting Earth would need to be about 100 feet or larger in order to cause significant damage in a populated area. The space agency said less than one percent of the 100-foot-sized NEOs have been detected.

 

“These days we average three NEO discoveries a day, and each month the Minor Planet Center receives hundreds of thousands of observations on asteroids, including those in the main-belt,” said Tim Spahr, director of the Minor Planet Center. “The work done by the NASA surveys, and the other international professional and amateur astronomers, to discover and track NEOs is really remarkable.”

 

Earlier this month, NASA announced a grand challenge focused on finding all asteroid threats to human populations. This “Great Challenge” asks citizen scientists, along with industry professionals, to focus on detecting and characterizing asteroids and learn how to deal with potential threats.

 

“We will also harness public engagement, open innovation and citizen science to help solve this global problem,” said NASA Deputy Administrator Lori Garver.

 

The space agency also invited industry and potential partners to offer up some ideas on accomplishing NASA’s goals to locate, redirect and explore an asteroid.

 

 

 

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Supermoon Coming June 24th

The Moon appears to be in a nearly circular orbit around the Earth. But that word “nearly” means that there are slight variations in its motion across the heavens.

As it turns out, the distance from the Earth to the Moon varies by about 30,000 miles. This sounds like a lot, but it only represents about a 6-7 percent deviation from the average distance between the two bodies.

On Earth, the difference between when the Moon is at its closest point (perigee) and its farthest position (apogee) causes the Moon to appear slightly smaller or larger in the sky. [Note: these terms can be a little confusing, because perigee and apogee vary after each orbit, which means they change from month to month and year to year. So they really represent the nearest and farthest points in the lunar orbit over a specific period of time.]

On June 24th, the Moon will be in a nearly full moon phase as it reaches perigee, making it appear slightly larger in the night sky. On that day, the Moon will be the closest to Earth that it will be for all of 2013. Such approaches, when perigee coincides closely with a full moon, are known as supermoons. But the apparent size difference is very difficult to see; only careful measurements reveal the difference.

This particular supermoon is actually not that great. Occurrences in each of the coming years will be even better. The best one of the century won’t happen until December 6, 2052. And the Moon will not cross within 356,400 kilometers until January 1, 2257 (356,371 km), a truly rare approach!

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Ancient Martians May Have Been Hydrogen Powered

While it’s hard to imagine much life surviving on the arid surface of Mars, there’s still some hope of finding Martian life in underground habitats. But for any life forms to survive, they’d need some kind of energy source, like the way we breathe oxygen. One interesting possibility is that Mars life may be hydrogen powered.

Top 10 Places To Find Alien Life

A group of researchers led by Lisa Mayhew, of CU Boulder, has identified a particular chemical reaction that may take place between iron-containing minerals and water, which produces hydrogen gas. So much hydrogen gas, in fact, that it could potentially support life in underground habitats — either here on our own planet, or in similar ecological niches on Mars.

Specifically, this chemical reaction is known to occur between seawater and igneous rocks under the ocean floor. Near hydrothermal vents, at high temperatures, the rocks release iron ions into the water that react with the surrounding water to produce iron oxides and hydrogen gas.

While this hydrogen (dissolved in the water) is produced in regions too hot for life to flourish (over 200°C), it seeps out from the rocks into cooler regions where some microbes are already known to be sustained by it. Mayhew and her colleagues have found the first evidence that this reaction can work perfectly well at lower temperatures too. She explains, ”Water-rock reactions that produce hydrogen gas are thought to have been one of the earliest sources of energy for life on Earth.”

“However,” she elaborated, “we know very little about the possibility that hydrogen will be produced from these reactions when the temperatures are low enough that life can survive. If these reactions could make enough hydrogen at these low temperatures, then microorganisms might be able to live in the rocks where this reaction occurs, which could potentially be a huge subsurface microbial habitat for hydrogen-utilizing life.”

ANALYSIS: Intraterrestrials: Mars Life May Hide Deep Below

With a reaction like this happening so easily, it gives some interesting insight into how primitive life may have survived on the infant Earth — and if primitive terrestrial life could have survived this way, then primitive Martian life could have just as easily done the same.

Could hydrogen-powered life have lived on Mars? Currently, the possibility still can’t be ruled out. A mechanism like this one could certainly have provided a plentiful supply of energy for indigenous martian microbes. Mayhew and her team found that hydrogen could be produced at temperatures in the range of 50-100°C, by rocks containing a specific mineral called spinel.

Spinels are a common type of mineral found on both Mars and Earth (they’re often found together with rubies here on our own planet). On close investigation, the researchers found that the spinels helped facilitate the formation of hydrogen, allowing the reaction to proceed even at lower temperatures than it had been observed before.

Lifestyles of the Modern Martian

While modern Mars may not be burdened with an overabundance of water, it was almost certainly a much more watery world in the past. The recent discovery of martian pebbles give incontestable proof that rivers once flowed on Mars. That said, there’s some evidence that Mars may still be hiding water. Previously, other rock-water reactions, such as serpentinisation, have been suggested before to explain the presence of methane gas in the Martian atmosphere.

The truth is, Mars is a mysterious little world. We’ve been sending robot explorers there for decades, but there’s a lot about it which is still a little puzzling. That said, we understand a lot more about our planetary neighbor now than ever before, and some things about it are, frankly, quite familiar.

As it happens, Mars is familiar enough that some astrobiologists are confident that if we can find life anywhere else in our solar system, we might find it there. After all, it’s not all that much colder than Earth, and has none of the searing heat and acid skies found on certain other nearby planets.

If Mars is hiding warmer temperatures and liquid water below its surface, it’s just possible that some kind of Martian life might be hiding underground even today. While there’s no way of saying for certain, it’s an intriguing possibility.

 

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