NASA probe beams back ultraviolet images of Martian atmosphere

October 18, 2016

Washington, Oct 18: In a first, NASA's MAVEN spacecraft has beamed back ultraviolet images of Mars that unveils dynamic, previously invisible activities in the atmosphere of the red planet such as change in ozone levels over the seasons and formation of clouds.master

The images were taken by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile Evolution mission (MAVEN) - a space probe designed to study the Martian atmosphere while orbiting Mars.

These were then used to make this movie of rapid cloud formation on Mars on July this year.

The movie uses four MAVEN images to show about seven hours of Mars rotation during this period, and interleaves simulated views that would be seen between the four images.

"MAVEN obtained hundreds of such images in recent months, giving some of the best high-resolution ultraviolet coverage of Mars ever obtained," said Nick Schneider from the University of Colorado, Boulder in the US.

Nightside images show ultraviolet (UV) "nightglow" emission from nitric oxide (NO). Nightglow is a common planetary phenomenon in which the sky faintly glows in the complete absence of external light.

Mars' nightside atmosphere emits light in the ultraviolet due to chemical reactions that start on Mars' dayside.

Ultraviolet light from the Sun breaks down molecules of carbon dioxide and nitrogen, and the resulting atoms are carried around the planet by high-altitude wind patterns that encircle the planet.

On the nightside, these winds bring the atoms down to lower altitudes where nitrogen and oxygen atoms collide to form nitric oxide molecules. The recombination releases extra energy, which comes out as ultraviolet light.

Scientists predicted NO nightglow at Mars, and prior missions detected its presence, but MAVEN has returned the first images of this phenomenon in the Martian atmosphere.

Splotches and streaks appearing in the images occur where NO recombination is enhanced by winds.

Such concentrations are clear evidence of strong irregularities in Mars' high altitude winds and circulation patterns. These winds control how Mars' atmosphere responds to its very strong seasonal cycles.

Dayside images show the atmosphere and surface near Mars' south pole in unprecedented ultraviolet detail. They were obtained as spring comes to the southern hemisphere.

Ozone is destroyed when water vapour is present, so ozone accumulates in the winter polar region where the water vapour has frozen out of the atmosphere.

The images show ozone lasting into spring, indicating that global winds are inhibiting the spread of water vapour from the rest of the planet into winter polar regions.

MAVEN observations also show afternoon cloud formation over the four giant volcanoes on Mars.
Clouds are a key to understanding a planet's energy balance and water vapour inventory, so these observations will be valuable in understanding the daily and seasonal behaviour of the atmosphere, researchers said.

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Agencies
May 17,2020

Washington, May 17: The overall number of global coronavirus cases has increased to over 4.6 million, while the death toll has surpassed 311,000, according to the Johns Hopkins University.

As of Sunday morning, the total number of cases stood at 4,634,068, while the death toll increased to 311,781, the University's Center for Systems Science and Engineering (CSSE) revealed in its latest update.

The US currently accounts for the world's highest number of cases and deaths at 1,467,796 and 88,754, respectively.

In terms of cases, Russia has the second highest number of infections at 272,043, followed by the UK (241,461), Brazil (233,142), Spain (230,698), Italy (224,760), France (179,630), Germany (175,752), Turkey (148,067) and Iran (118,392), the CSSE figures showed.

Meanwhile, the UK accounted for the second highest COVID-19 deaths worldwide at 34,546.

The other countries with over 10,000 deaths are Italy (31,763), Spain (27,563), France (27,532), and Brazil (15,662).

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News Network
June 26,2020

Washington, Jun 26: The US is reviewing its global deployment of forces to ensure it is postured appropriately to counter the People's Liberation Army, given the increasing threat posed by China to Asian countries like India, Malaysia, Indonesia, and the Philippines, Secretary of State Mike Pompeo said on Thursday.

Mr Pompeo made those remarks in response to a question during the virtual Brussels Forum 2020 of the German Marshall Fund.

"We're going to make sure we're postured appropriately to counter the PLA. We think that the challenge of our times, and we're going to make sure we have resources in place to do that," Mr Pompeo said.
 
The force posture review is being done at the direction of President Donald Trump, as part of which the US is reducing the number of its troops in Germany from about 52,000 to 25,000, he said.

Mike Pompeo said that the force posture would be dictated by the ground realities.

"In certain places there will be fewer American resources. There'll be other places - I just talked about the threat from the Chinese Communist Party, so now threats to India, threats to Vietnam, threats to Malaysia, Indonesia, South China Sea challenges, the Philippines," he said.

"To the extent that that changed, the difference in what the US decided to do impacts adversely a threat some place, it may be that other nations need to step up and take responsibility for their own defense in ways that they hadn't done previously. So, we want to do this in full consultation with all of our partners all around the world, and certainly our friends in Europe," Mr Pompeo said.

President Trump is being criticised for reducing troops from Germany. His critics say that this will increase the threat from Russia to Europe.

Mike Pompeo, however, did not agree with that argument.

It has been a long time since there has been a strategic review of our force posture all across the world. The US undertook that starting about 2.5 years ago, whether that was our forces in Africa, our forces in Asia, the force we have in the Middle East and in Europe, he said.

"We began to say these are often decisions that were made in a different time. Should we reallocate those a different way? Should we have a different composition of those forces? Everyone always wants to talk about ground troops. I get it. I was a young tank officer. You described that. There's nothing I like as much as a good M1 tank.

"But it's often the case that the capacity to deter Russia or other adversaries isn''t determined any longer by just having a bunch of folks garrisoned someplace. So, we really went to back fundamentally relook, what is the nature of the conflict, what''s the nature of the threat, and how should we allocate our resources, whether that''s our resources in the intelligence community, our resources from the Air Force or the Marines and Army," Mr Pompeo said.

Last week, Mike Pompeo criticised the Chinese Army for "escalating" the border tension with India and militarising the strategic South China Sea. He also described the ruling Communist Party of China (CPC) as a "rogue actor".

"Our broad set of allocation of security apparatus, our ability to counter cyber threats, how do we allocate them? What''s the best way to do this? And the decision that you see the president made with respect to Germany is an outcome from a collective set of decisions about how we''re going to posture our resources around the world," said the top American diplomat on Thursday.

Changes in force posture is being taken in consultations with allies and friends, Mr Pompeo said.

"President Trump has spoken to this. (Defense) Secretary (Mark) Esper will be in London today and in Brussels tomorrow. We''ll talk about our plan and how we''re thinking about delivering it," he said.

"But you should understand this, and I hope our European partners will understand this as well. When you see what we ultimately conclude, how we ultimately deliver on the statements of the president made, that they''re aimed squarely at what we believe to be democracies'' fundamental interest and certainly America's most fundamental interest," Mr Pompeo said.

Earlier this month, Mike Pompeo had said that China's actions, be it on the India border, or in Hong Kong or in the South China Sea, were part of the behaviour of the ruling Communist Party in Beijing in the recent past.

China has been fast expanding military and economic influence in the Indo-Pacific region, triggering concern in various countries of the region and beyond.

China is engaged in hotly contested territorial disputes in both the South China Sea and the East China Sea. Beijing has built up and militarised many of the islands and reefs it controls in the region. Both areas are stated to be rich in minerals, oil and other natural resources and are vital to global trade.

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News Network
June 24,2020

Geneva, Jun 24: The global cumulative count of confirmed coronavirus cases is approaching nine million, with 133,326 cases recorded over the past day, the World Health Organisation (WHO) said in its daily situation report on Tuesday.

Over the past 24 hours, 3,847 people died from COVID-19 worldwide, taking the cumulative death toll to 469,587 fatalities, according to the report.

The global case total has now reached 8,993,659.

The Americas still account for the majority of cases and deaths -- 4.4 million and 224,207, respectively.

The United States remains the country with the highest count of cases and fatalities -- 2.3 million and 119,761, respectively.

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