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Showing posts with label national geographic. Show all posts
Showing posts with label national geographic. Show all posts

Monday, March 26, 2012

James Cameron Completes Record-Breaking Mariana Trench Dive

James Cameron
James Cameron emerges from his sub after returning from Challenger Deep

At noon, local time (10 p.m. ET), James Cameron's "vertical torpedo" sub broke the surface of the western Pacific, carrying the National Geographic explorer and filmmaker back from the Mariana Trench's Challenger Deep—Earth's deepest, and perhaps most alien, realm.

The first human to reach the 6.8-mile-deep (11-kilometer-deep) undersea valley solo, Cameron arrived at the bottom with the tech to collect scientific data, specimens, and visions unthinkable in 1960, when the only other manned Challenger Deep dive took place, according to members of the National Geographic expedition.

After a faster-than-expected, roughly 70-minute ascent, Cameron's sub, bobbing in the open ocean, was spotted by helicopter and would soon be plucked from the Pacific by a research ship's crane. Earlier, the descent to Challenger Deep had taken 2 hours and 36 minutes.

Expedition member Kevin Hand called the timing of the DEEPSEA CHALLENGER sub's ascent "perfect."

"Jim came up in what must have been the best weather conditions we've seen, and it looks like there’s a squall on the horizon," said Hand, a NASA astrobiologist and National Geographic emerging explorer.

Before surfacing about 300 miles (500 kilometers) southwest of Guam, Cameron spent hours hovering over Challenger Deep's desert-like seafloor and gliding along its cliff walls, the whole time collecting samples and video.

Among the 2.5-story-tall sub's tools are a sediment sampler, a robotic claw, a "slurp gun" for sucking up small seacreatures for study at the surface, and temperature, salinity, and pressure gauges. (See pictures of Cameron's sub.)

Now "the science team is getting ready for the returned samples," said NASA's Hand.

Cameron—best known for creating fictional worlds on film (Avatar, Titanic, The Abyss)—is expected to announce his initial findings later today. After analysis, full results are to be published in a future edition of National Geographic magazine.

"The Ultimate Test"

Retired U.S. Navy Capt. Don Walsh, who descended to Challenger Deep in 1960, said he was pleased to hear that Cameron had reached the underwater valley safely.

"That was a grand moment, to welcome him to the club," Walsh, said in a telephone interview from the sub-support ship.

"There're only three of us in it, and one of them—late Swiss engineer Jacques Piccard—"is dead. Now it's just Jim and myself."

Expedition physician Joe MacInnis called Cameron’s successful descent today "the ultimate test of a man and his machine."

After breaching the ocean surface, the DEEPSEA CHALLENGER was first spotted by a helicopter owned by Microsoft co-founder Paul Allen, a longtime Cameron friend. Allen was on the scene for the historic dive and posted live updates of the event on Twitter from aboard his yacht, the Octopus, which is providing backup support for the mission.

Science in Three Dimensions

Throughout the Mariana Trench dive, 3-D video cameras were kept whirring, and not just for the benefit of future audiences of planned documentaries.

"There is scientific value in getting stereo images because ... you can determine the scale and distance of objects from stereo pairs that you can't from 2-D images," Cameron told National Geographic News before the dive.

But "it's not just the video. The sub's lighting of deepwater scenes—mainly by an 8-foot (2.5-meter) tower of LEDs—is "so, so beautiful," said Doug Bartlett, a marine biologist at the Scripps Institution of Oceanography in San Diego, California.

"It's unlike anything that you'll have seen from other subs or other remotely operated vehicles," said Bartlett, chief scientist for the DEEPSEA CHALLENGE project, a partnership with the National Geographic Society and Rolex. (The Society owns National Geographic News.)

Medical, Psychological Rigors

As the 57-year-old explorer emerged from the sub's coffin—tight 43-inch-wide (109-centimeter-wide) cockpit, a medical team stood at the ready.

But if recent test dives—including one to more than five miles (eight kilometers meters) down—are any indication, Cameron should be physically fine, despite having been unable to extend his arms and legs for hours, expedition physician Joe MacInnis told National Geographic News before the dive.

"Jim is going to be a little bit stiff and sore from the cramped position, but he's in really good shape for his age, so I don't expect any problems at all," said MacInnis, a long-time Cameron friend.

In addition, the sub's "pilot sphere" has a handlebar, which Cameron could use to pull himself occasionally up during the dive. "Usually, shifting position is all that's required to buy yourself another few hours," he said.

Because Cameron had prepared extensively for the dive, he should be in good psychological health, said Walter Sipes, an aeronautics psychologist at NASA's Johnson Space Center.

"He's got prior experience doing this, not just in the simulator but also training dives ... and he's an adventurer, so I really don't think they'll have any issues to worry about," said Sipes, who is not part of the expedition.

Still, if Cameron plans to conduct more dives—which the team has indicated he will—Sipes recommends he get plenty of rest in between or risk mental fatigue.

"When you start to get fatigued, you start making mistakes," he added. "And since he's down there solo, he can't afford that. He's a [potential] single-point failure."

It should be at least a few weeks before any further DEEPSEA CHALLENGE dives, as the director's next breakneck mission will take him from the middle of the Pacific to London, where he's due at a premiere of his Titanic 3-D Wednesday.

"A Turning Point"

By returning humans to the so-called hadal zone—the ocean's deepest level, below 20,000 feet (6,000 meters)—the Challenger Deep expedition may represent a renaissance in deep-sea exploration.

While remotely operated vehicles, or ROVs, are much less expensive than manned subs, "the critical thing is to be able to take the human mind down into that environment," expedition member Patricia Fryer said, "to be able to turn your head and look around to see what the relationships are between organisms in a community and to see how they're behaving—to turn off all the lights and just sit there and watch and not frighten the animals, so that they behave normally.

"That is almost impossible to do with an ROV," said Fryer, a marine geologist at the Hawai'i Institute of Geophysics & Planetology.

Andy Bowen, project manager and principal developer of the Nereus, an ROV that explored Challenger Deep in 2009, said a manned mission also has the potential to inspire public imagination in a way a robot can't.

"It's difficult to anthropomorphize machines in a way that engages everyone's imagination—not in the same way that having boots on the ground, so to speak, can do," said Bowen, who's not an expedition member.

Biological oceanographer Lisa Levin, also at Scripps, said that the DEEPSEA CHALLENGE program's potential for generating public interest in deep-ocean science is as important as any new species Cameron might have discovered.

"I consider Cameron to be doing for the trenches what Jacques Cousteau did for the ocean many decades ago," said Levin, who's part of the team but did not participate in the seagoing expedition.

At a time of fast-shrinking funds for undersea research, "what scientists need is the public support to be able to continue exploration and research of the deep ocean," Levin said.

Perhaps referring to his friend's most recent movie, expedition physician MacInnis called Cameron a real-world "avatar."

"He's down there on behalf of everybody else on this planet," he said. "There are seven billion people who can’t go, and he can. And he’s aware of that."

For his part, Cameron seems sure that the DEEPSEA CHALLENGER will be exploring the depths for a long time to come. In fact, he's so confident in his star vehicle, he started mulling sequels even before today's trench dive.

Phase two might include adding a thin fiber-optic tether to the ship, which "would allow science observers at the surface to see the images in real time," said Cameron, a National Geographic Society explorer-in-residence.

"And phase three might be taking this vehicle and creating a second-generation vehicle."

DEEPSEA CHALLENGE, then, may be anything but a one-hit wonder. To expedition chief scientist Bartlett, the Mariana Trench dive could "represent a turning point in how we approach ocean science.

"I absolutely think that what you're seeing is the start of a program, not just one grand expedition."




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Monday, December 12, 2011

Solar Storms Are "Sandblasting" the Moon, NASA Study Hints

solar storm
Solar Storm
The moon gets periodically "sandblasted" by intense solar storms that can strip tons of material from the lunar surface, a new NASA study suggests.

The sun is constantly emitting charged particles, or ions, in all directions in a stream called the solar wind. Scientists previously knew that solar ions can collide with and eject material on the moon's surface in a process dubbed sputtering.

But a new computer simulation finds that this sandblasting effect kicks into high gear during intense bursts of solar plasma—charged gas—known as coronal mass ejections (CMEs).

A strong CME can hurl about a billion tons of solar particles at up to a million miles (1.6 million kilometers) an hour in a cloud that is many times the size of Earth.

Normal solar wind is made up mostly of lightweight protons—hydrogen atoms that have been stripped of their electrons. But CMEs contain a much higher percentage of heavier ions such as helium, oxygen, and even iron.

These heavier atoms slam into the moon with greater force than protons, so they can dislodge a larger number of atoms from the surface.

"We found that when this massive cloud of plasma strikes the moon, it acts like a sandblaster and easily removes volatile material from the surface," study co-author William Farrell, leader of the Dynamic Response of the Environment At the Moon, or DREAM, team at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement.

"The model predicts 100 to 200 tons of lunar material—the equivalent of ten dump truck loads—could be stripped off the lunar surface during the typical two-day passage of a large CME."

Once ejected, about 90 percent of sputtered moon particles escape into space, where they become ionized and are drawn into the solar wind, said study co-author Rosemary Killen, also of NASA Goddard.

"The material is in atomic form," Killen added in an email to National Geographic News. "It is not meteoric and does not produce meteor showers" on Earth.

Sputtering Can Help Probe Moon's Chemistry?

CMEs are most likely to happen during solar maximum, a period of high magnetic activity on the sun that occurs about once every 11 years.

"The more active the sun, the more often coronal mass ejections take place," said Richard Elphic, a planetary scientist at the NASA Ames Research Center in California who was not involved in the study.

"You can have at the height of solar maximum a [large] CME maybe every week or so, and in some cases every few days. And that might be followed by a couple weeks of quiet."

Right now the sun is ramping up toward the next predicted solar maximum in 2013—which might aid research that uses sputtering to reveal clues about lunar chemistry.

A new moon orbiter scheduled to launch in 2013, called the Lunar Atmosphere And Dust Environment Explorer, or LADEE, could test the new model's predictions.

If the simulation is correct, then CME sputtering should loft lunar surface atoms to LADEE's orbital altitude, around 12 to 30 miles (20 to 50 kilometers).

"As the LADEE project scientist," Elphic said, "my excitement is in using these CME 'scavenging events' as active probes of the sputtering process, to learn what [types of atoms] are liberated and how long they stick around before equilibrium returns."

Moon Landing Footprints in No Danger

While the new model hints that the amount of lunar material stripped off by sputtering is more than scientists had thought, the amount of lost material is still very small compared to the total mass of the moon.

Also, the loss of lunar surface material is more or less balanced by incoming particles from micrometeorites, meteors, and the solar wind itself.

That means Earth's only natural satellite—and the features on it—are in no danger of being eroded away anytime soon. (Also see "The Moon Has Shrunk, and May Still Be Contracting.")

"The astronaut's footprints will still be there in recognizable form after a million years—if we're still around to see them," Elphic said.

News by Nationalgeographic


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