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Extra heat trapped inside Pacific, Indian ocean : NASA

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Washington: A layer of the Indian and Pacific oceans, between 100-300 metres below the surface, has been accumulating more heat than previously recognized, thus temporarily hiding global warming, NASA has reported.

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The study of ocean temperature measurements shows that in recent years, extra heat from greenhouse gases has been trapped in the waters of the Pacific and Indian oceans.

According to researchers, this shifting pattern of ocean heat accounts for the slowdown in the global surface temperature trend observed during the past decade.

“Greenhouse gases continued to trap extra heat but for about 10 years starting in the early 2000s, global average surface temperature stopped climbing, and even cooled a bit, explained Josh Willis from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

During the 20th century, as greenhouse gas concentrations increased and trapped more heat energy on Earth, global surface temperatures also increased.

However, in the 21st century, this pattern seemed to change temporarily.

The study, published in the journal Science, also found that the movement of warm water has affected surface temperatures.

Researchers Veronica Nieves, Willis and Bill Patzert analysed direct ocean temperature measurements, including observations from a global network of about 3,500 ocean temperature probes known as the Argo array.

These measurements show temperatures below the surface have been increasing.

The Pacific Ocean is the primary source of the subsurface warm water found in the study, though some of that water now has been pushed to the Indian Ocean.

Since 2003, unusually strong trade winds and other climatic features have been piling up warm water in the upper 1,000 feet of the western Pacific, pinning it against Asia and Australia.

“The western Pacific got so warm that some of the warm water is leaking into the Indian Ocean through the Indonesian archipelago,” Nieves noted.

Pauses of a decade or more in Earth’s average surface temperature warming have happened before in modern times, with one occurring between the mid-1940s and late 1970s.

“In the long term, there is robust evidence of unabated global warming,” Nieves said.

(IANS)

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“It Is A More Rugged Surface Than We Predicted,” NASA’s Plan to Scoop Up Dirt from Asteroid Hits Complication

A Japanese spacecraft, Hayabusa2, touched down on another asteroid in February, also on a mission to collect material. Japan managed to return some tiny particles in 2010 from its first asteroid mission.

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This artist's rendering made available by NASA in July 2016 shows the mapping of the near-Earth asteroid Bennu by the OSIRIS-REx spacecraft. VOA

NASA’s plan to scoop up dirt and gravel from an asteroid has hit a snag, but scientists say they can overcome it.

The asteroid Bennu was thought to have wide, open areas suitable for the task. But a recently arrived spacecraft revealed the asteroid is covered with boulders and there don’t seem to be any big, flat spots that could be used to grab samples.

In a paper released Tuesday by the journal Nature, scientists say they plan to take a closer look at a few smaller areas that might work. They said sampling from those spots poses “a substantial challenge.”

“But I am confident this team is up to that substantial challenge,” the project’s lead scientist, Dante Lauretta, told reporters at a news conference Tuesday.

The spacecraft, called Osiris-Rex, is scheduled to descend close to the surface in the summer of 2020. It will extend a robot arm to pick up the sample, which will be returned to Earth in 2023. The spacecraft began orbiting Bennu at the end of last year, after spending two years chasing down the space rock.

FILE - This Nov. 16, 2018, image provide by NASA shows the asteroid Bennu.
This Nov. 16, 2018, image provide by NASA shows the asteroid Bennu. VOA

When the mission was planned, scientists were aiming to take dirt and gravel from an area measuring at least 55 yards (50 meters) in diameter that was free of boulders or steep slopes, which would pose a hazard.

“It is a more rugged surface than we predicted,” said Lauretta, of the University of Arizona in Tucson and one of the paper’s authors. But he said he believed a sample could still be collected.

NASA project manager Rich Burns said a spot will be chosen this summer and the setback won’t delay the sampling.

Patrick Taylor, who studies asteroids at the Lunar and Planetary Institute in Houston but didn’t participate in the spacecraft mission, noted in a telephone interview that the spacecraft was evidently maneuvering more accurately and precisely than had been expected.

“That gives me confidence they will be able to attempt a sample acquisition,” he said.

NASA
NASA project manager Rich Burns said a spot will be chosen this summer and the setback won’t delay the sampling. VOA

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Bennu is 70 million miles (110 million kilometers) from Earth. It’s estimated to be just over 1,600 feet (500 meters) across and is the smallest celestial body ever orbited by a spacecraft.

A Japanese spacecraft, Hayabusa2, touched down on another asteroid in February, also on a mission to collect material. Japan managed to return some tiny particles in 2010 from its first asteroid mission. (VOA)