3D images show what lies beneath Mars poles

January 4, 2017

Washington, Jan 4: Scientists using data from a NASA probe have unveiled 3D subsurface images of Mars polar ice caps, showing previously obscured layering, larger volume of frozen carbon dioxide and bowl-shaped features that may be buried impact craters.mars

The information will help scientists better understand Martian climate changes and may allow them to determine the age of the polar caps without using climate models.

The 3D data volumes were assembled from observations by the Shallow Radar (SHARAD) onboard NASA's Mars Reconnaissance Orbiter (MRO) during more than 2000 orbit passes over each Martian pole.

"We have applied industry-developed techniques in a very novel fashion to a martian dataset, producing 3D volumes that are each over 600 times larger than any terrestrial or planetary dataset of this kind," said Nathaniel E Putzig, a senior scientist at the Planetary Science Institute in the US.

"It is gratifying to see so plainly in the SHARAD volumes structures that took years of effort to characterise with the single-orbit profiles," Putzig said.

Layering seen at the surface of the martian polar caps has been studied for decades. It has long been thought to represent a record of climate changes on that planet.

The interior structures of the caps remained a mystery until the arrival of radar sounders at Mars in the last decade.

An early version of the north polar 3D volume helped to assess the quantity of water ice transferred to the polar caps in the most recent retreat from a martian ice age.

First looks at the south polar 3D volume indicate that previously mapped deposits of carbon dioxide ice are somewhat larger than reported.

In both polar 3D volumes, known impact craters in and near the polar caps that are partially filled with ice have distinctive bowl-shaped signatures in the radar data, and similar signatures are found elsewhere within the polar ices but without any surface expression.

Whether the latter structures truly are impact craters remains to be determined.
Age estimates of planetary surfaces throughout the solar system rely on statistical data for impact craters on the Moon's surface calibrated to radiometrically dated samples returned during the Apollo programme.

This method has been used to estimate the surface ages of the martian polar caps, but estimates for the ages of the caps themselves have had to rely on numerical models of past climate changes.

If a sufficient number of the bowl-shaped features found in the radar volumes are shown to be impact craters, scientists will be able to assess the age of the polar caps using cratering statistics alone.

The extent to which age estimates from this new volumetric method agree or disagree with those from climate models will have important implications for the accuracy of these dating techniques.

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Agencies
June 7,2020

New Delhi, Jun 7: The Government of India (GoI) must strengthen the laws to protect animals, said People for the Ethical Treatment of Animals (PETA) India CEO Dr Manilal Valliyate on Sunday, following an elephant's death in Kerala and cow injured due to ingestion of explosives in Himachal Pradesh.

"Such incidents are not just restricted to certain regions but are happening all across the country. PETA receives more than 100 similar cases every day. People send in their complaints to us, not just for cows and elephants but for so many other animals as well," he said.

The PETA chief urged the GoI to strengthen the laws established to protect animals.

"As per the current laws set out against animal cruelty, the perpetrator would only be charged Rs 50,000 as a fine. That is equivalent to no punishment at all," added PETA India CEO.

He expressed his anguish against municipal agencies as well, saying that they are not doing "serious" work. He also highlighted how cows are left on the roads to wander, after milking them, to feed on garbage, in several parts of the country.

"These injustices against animals through explosives has been going on for quite a while. But for the first time, it has received such public attention," he said.

After a pregnant elephant was fed cracker-filled pineapple and her eventual death on May 27 in Kerala's Palakkad district, a pregnant cow sustained fatal injuries on May 25 due to accidental ingestion of explosives in Dadh village of Bilaspur district of Himachal Pradesh.

One person has been arrested in the Dadh village for allegedly hurting the cow.

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Agencies
May 31,2020

Cape Canaveral, May 31: SpaceX, the private rocket company of billionaire entrepreneur Elon Musk, launched two Americans into orbit from Florida on Saturday in a landmark mission marking the first spaceflight of NASA astronauts from U.S. soil in nine years.

A SpaceX Falcon 9 rocket lifted off from the Kennedy Space Center at 3:22 p.m. EDT (19:22 GMT), launching Doug Hurley and Bob Behnken on a 19-hour ride aboard the company’s newly designed Crew Dragon capsule bound for the International Space Station.

Just before liftoff, Hurley said, “SpaceX, we’re go for launch. Let’s light this candle,” paraphrasing the famous comment uttered on the launch pad in 1961 by Alan Shepard, the first American flown into space.

Minutes after launch, the first-stage booster rocket of the Falcon 9 separated from the upper second-stage rocket and flew itself back to Earth to descend safely onto a landing platform floating in the Atlantic.

High above the Earth, the Crew Dragon jettisoned moments later from the second-stage rocket, sending the capsule on its way to the space station.

The exhilarating spectacle of the rocket soaring flawlessly into the heavens came as a welcome triumph for a nation gripped by racially-charged civil unrest as well as ongoing fear and economic upheaval from the coronavirus pandemic.

The Falcon 9 took off from the same launch pad used by NASA’s final space shuttle flight, piloted by Hurley, in 2011. Since then, NASA astronauts have had to hitch rides into orbit aboard Russia’s Soyuz spacecraft.

“It’s incredible, the power, the technology,” said U.S. President Donald Trump, who was at Kennedy Space Center at Cape Canaveral in Florida for the launch. “That was a beautiful sight to see.”

The mission’s first launch attempt on Wednesday was called off with less than 17 minutes remaining on the countdown clock. Weather again threatened Saturday’s launch, but cleared in time to proceed with the mission.

SPACEFLIGHT MILESTONES

NASA chief Jim Bridenstine has said resuming launches of American astronauts on American-made rockets from U.S. soil is the space agency’s top priority.

“I’m breathing a sigh of relief, but I will also tell you I’m not gonna celebrate until Bob and Doug are home safely.” Bridenstine said.

For Musk, the launch represents another milestone for the reusable rockets his company pioneered to make spaceflight less costly and more frequent. And it marks the first time commercially developed space vehicles - owned and operated by a private entity rather than NASA - have carried Americans into orbit.

The last time NASA launched astronauts into space aboard a brand new vehicle was 40 years ago at the start of the space shuttle program.

Musk, the South African-born high-tech entrepreneur who made his fortune in Silicon Valley, is also chief executive of electric carmaker and battery manufacturer Tesla Inc. He founded Hawthorne, California-based SpaceX, formally known as Space Exploration Technologies, in 2002.

Hurley, 53, and Behnken, 49, NASA employees under contract to fly with SpaceX, are expected to remain at the space station for several weeks, assisting a short-handed crew aboard the orbital laboratory.

Boeing Co, producing its own launch system in competition with SpaceX, is expected to fly its CST-100 Starliner vehicle with astronauts aboard for the first time next year. NASA has awarded nearly $8 billion combined to SpaceX and Boeing for development of their rival rockets.

Trump also hailed the launch as a major advance toward the goal of eventually sending humans to Mars.

He was joined at the viewing by Musk, as well as Vice President Mike Pence, Commerce Secretary Wilbur Ross, Education Secretary Betsy DeVos, Florida congressman Matt Gaetz and Senator Rick Scott.

Earlier on Saturday, the crew bid goodbye to their families. Prior to climbing into a specially designed Tesla automobile for the ride to the launch site, Behnken told his young son, “Be good for mom. Make her life easy.”

During the drive, Behnken and Hurley passed former astronaut Garrett Reisman who held a sign saying, “Take me with you.”

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Agencies
June 16,2020

Paris, Jun 16: Increasing numbers of readers are paying for online news around the world even if the level of trust in the media, in general, remains very low, according to a report published Tuesday.

Around 20 percent of Americans questioned said they subscribed to an online news provider (up to four points over the previous year) and 42 percent of Norwegians (up eight points), along with 13 percent of the Dutch (up to three points), compared with 10 percent in France and Germany.

But between a third and a half of all news subscriptions go to just a few major media organisations, such as the New York Times, according to the annual Digital News Report by the Reuters Institute.

Some readers, however, are also beginning to take out more than one subscription, paying for a local or specialist title in addition to a national news source, the study's authors said.

But a large proportion of internet users say nothing could convince them to pay for online news, around 40 percent in the United States and 50 percent in Britain.

YouGov conducted the online surveys of 40 countries for the Reuters Institute in January, with 2,000 respondents in each.

Further surveys were carried out in six countries in April to analyse the initial effects of COVID-19.

The health crisis brought a revival of interest in television news -- with the audience rising five percent on average -- establishing itself as the main source of information along with online media.

Conversely, newspaper circulation was hard-hit by coronavirus lockdown measures.

The survey found trust in the news had fallen to its lowest level since the first report in 2012, with just 38 percent saying they trusted most news most of the time.

However, confidence in the news media varied considerably by country, ranging from 56 percent in Finland and Portugal to 23 percent in France and 21 percent in South Korea.

In Hong Kong, which has been hit by months of sometimes violent street protests against an extradition law, trust in the news fell 16 points to 30 percent over the year.

Chile, which has had regular demonstrations against inequality, saw trust in the media fall 15 percent while in Britain, where society has been polarised by issues such as Brexit, it was down 12 points.

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