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
June 27,2020

Washington, Jun 27: Facebook has said that it will flag all "newsworthy" posts from politicians that break its rules, including those from President Donald Trump.

Separately, Facebook's stock dropped more than 8 per cent, erasing roughly USD 50 billion from its market valuation, after the European company behind brands such as Ben & Jerry's and Dove announced it would boycott Facebook ads through the end of the year over the amount of hate speech and divisive rhetoric on its platform.

Later in the day, Coca-Cola also announced it joined the boycott for at least 30 days.

CEO Mark Zuckerberg had previously refused to take action against Trump posts suggesting that mail-in ballots will lead to voter fraud, saying that people deserved to hear unfiltered statements from political leaders.

Twitter, by contrast, slapped a "get the facts" label on them.

Until Friday, Trump's posts with identical wording to those labelled on Twitter remained untouched on Facebook, sparking criticism from Trump's opponents as well as current and former Facebook employees.

Now, Facebook is all but certain to face off with the president the next time he posts something the company deems to be violating its rules.

"The policies we're implementing today are designed to address the reality of the challenges our country is facing and how they're showing up across our community," Zuckerberg wrote on his Facebook page announcing the changes.

Zuckerberg said the social network is taking additional steps to counter election-related misinformation.

In particular, the social network will begin adding new labels to all posts about voting that will direct users to authoritative information from state and local election officials.

Facebook is also banning false claims intended to discourage voting, such as stories about federal agents checking legal status at polling places.

The company also said it is increasing its enforcement capacity to remove false claims about local polling conditions in the 72 hours before the US election.

Ethan Zuckerman, director of the Massachusetts Institute of Technology's Center for Civic Media, said the changes are a "reminder of how powerful Facebook may be in terms of spreading disinformation during the upcoming election".

He said the voting labels will depend on how good Facebook's artificial intelligence is at identifying posts to label.

"If every post that mentions voting links, people will start ignoring those links. If they're targeted to posts that say things like 'Police will be checking warrants and unpaid traffic tickets at polls' a classic voter suppression disinfo tactic and clearly mark posts as disinfo, they might be useful," he said.

But Zuckerman noted that Facebook "has a history of trying hard not to alienate right-leaning users, and given how tightly President Trump has aligned himself with voter-suppressing misinfo, it seems likely that Facebook will err on the side of non-intrusive and ignorable labels, which would minimize impact of the campaign."

Earlier in the day, shares of Facebook and Twitter dropped sharply after consumer-product maker Unilever announced a new ad boycott on Facebook, Twitter and Instagram through at least the end of the year.

The European company said it took the move to protest the amount of hate speech online.

Unilever said the polarised atmosphere in the United States ahead of November's presidential election placed responsibility on brands to act.

In addition to the decline in Facebook shares, Twitter ended the day more than 7 per cent lower.

Unilever, which is based in the Netherlands and Britain, joins a raft of other advertisers pulling back from online platforms.

Facebook in particular has been the target of an escalating movement to withhold advertising dollars to pressure it to do more to prevent racist and violent content from being shared on its platform.

"We have decided that starting now through at least the end of the year, we will not run brand advertising in social media newsfeed platforms Facebook, Instagram and Twitter in the U.S.," Unilever said.

"Continuing to advertise on these platforms at this time would not add value to people and society."

Facebook did not immediately respond to a request for comment. On Thursday, Verizon joined others in the Facebook boycott.

Unilever "has enough influence to persuade other brand advertisers to follow its lead," said eMarketer analyst Nicole Perrin.

She noted that Unilever pulled back spending "for longer, on more platforms (including Twitter) and for more expansive reasons" in particular, by citing problems with "divisiveness" as well as hate speech.

Sarah Personette, vice president of global client solutions at Twitter, said the company's "mission is to serve the public conversation and ensure Twitter is a place where people can make human connections, seek and receive authentic and credible information, and express themselves freely and safely."

She added that Twitter is "respectful of our partners' decisions and will continue to work and communicate closely with them during this time."

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News Network
July 2,2020

Jul 2: Democratic presidential candidate and former US vice-president Joe Biden has said that if he wins the November elections, strengthening the relationship with India which is America’s "natural partner", will be a high priority for his administration.

"India needs to be a partner in the region for our safety's sake and quite frankly for theirs," he said in response to a question on India-US relationship during a virtual fundraiser event on Wednesday.

At the fundraiser hosted by Chairman and CEO of Beacon Capital Partners Alan Leventhal, the former vice president said that India and the United States were natural partners.

"That partnership, a strategic partnership, is necessary and important in our security," Biden said when asked by an attendee whether India is critical to the US' national security.

Referring to his eight years as the vice president, he said, "In our administration, I was proud to play a role more than a decade ago in securing Congressional approval for the US-India Civil Nuclear Agreement, which is a big deal".

"Helping open the door to great progress in our relationship and strengthening our strategic partnership with India was a high priority in the Obama-Biden administration and will be a high priority if I'm elected president,” Biden said.

Both as the vice president and a senator from Delaware, he was a big supporter of India-US relationship.

About the November polls, Biden said that the character of the country is on the ballot. The upcoming election is the most important poll of a lifetime and that the country is currently engaged in a battle for its soul, he claimed.

Biden also slammed President Donald Trump and his administration over the handling of the coronavirus pandemic.

"Trump ignored warnings from the very beginning, refused to prepare and failed to protect the country. Not just now but throughout his presidency, undermining the very core pillars of ours, what I would argue, moral and economic strength.

"I really do believe that our country is crying out for leadership and maybe even more important, some healing. Today, we have an enormous opportunity not only to rebuild but to build back better than before. To build a better future. That's what America does," he added.

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News Network
April 26,2020

Apr 26: The Chinese city of Wuhan, where the global coronavirus pandemic began, now has no remaining cases in its hospitals, a health official told reporters on Sunday.

"The latest news is that by April 26, the number of new coronavirus patients in Wuhan was at zero, thanks to the joint efforts of Wuhan and medical staff from around the country," National Health Commission spokesman Mi Feng said at a briefing.

The city had reported 46,452 cases, 56% of the national total. It saw 3,869 fatalities, or 84% of China's total.

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