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.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
July 24,2020

The total number of global coronavirus cases has topped 15.4 million, while the deaths have increased to over 631,000, according to the Johns Hopkins University.

As of Friday morning, the total number of cases stood at 15,439,456, while the fatalities rose to 631,926, the University's Center for Systems Science and Engineering (CSSE) revealed in its latest update.

The US accounted for the world's highest number of infections and fatalities at 4,034,831 and 144,242, respectively, according to the CSSE.

Brazil came in the second place with 2,287,475 infections and 84,082 deaths.

In terms of cases, India ranks third (1,238,798), and is followed by Russia (793,720), South Africa (408,052), Peru (371,096), Mexico (370,712), Chile (334,683), the UK (298,721), Iran (284,034), Spain (270,166), Pakistan (269,191), Saudi Arabia (260,394), Italy (245,338), Turkey (223,315), Colombia (218,428), France (216,667), Bangladesh (216,110), Germany (204,881), Argentina (148,027), Canada (114,398), Qatar (108,244) and Iraq (102,226), the CSSE figures showed.

The other countries with over 10,000 deaths are the UK (45,639), Mexico (41,908), Italy (35,092), France (30,185), India (29,861), Spain (28,429), Iran (15,074), Peru (17,654) and Russia (12,873).

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
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."

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
News Network
April 12,2020

Apr 12: India and other South Asian countries are likely to record their worst growth performance in four decades this year due to the coronavirus outbreak, the World Bank said on Sunday.

The South Asian region, comprising eight countries, is likely to show economic growth of 1.8 per cent to 2.8 per cent this year, the World Bank said in its South Asia Economic Focus report, well down from the 6.3 per cent it projected six months ago.

India's economy, the region's biggest, is expected to grow 1.5 per cent to 2.8 per cent in the fiscal year that started on April 1. The World Bank has estimated it will grow 4.8 per cent to 5 per cent in the fiscal year that ended on March 31.

"The green shoots of a rebound that were observable at the end of 2019 have been overtaken by the negative impacts of the global crisis," the World Bank report said.

Other than India, the World Bank forecast that Sri Lanka, Nepal, Bhutan and Bangladesh will also see sharp falls in economic growth.

Three other countries - Pakistan, Afghanistan and the Maldives - are expected to fall into recession, the World Bank said in the report, which was based on country-level data available as of April 7.

Measures taken to counter the coronavirus have disrupted supply chains across South Asia, which has recorded more than 13,000 cases so far - still lower than many parts of the world.

India's lockdown of 1.3 billion people has also left millions out of work, disrupted big and small businesses and forced an exodus of migrant workers from the cities to their homes in villages.

In the event of prolonged and broad national lockdowns, the report warned of a worst-case scenario in which the entire region would experience an economic contraction this year.

To minimize short-term economic pain, the Bank called for countries in the region to announce more fiscal and monetary steps to support unemployed migrant workers, as well as debt relief for businesses and individuals.

India has so far unveiled a $23 billion economic plan to offer direct cash transfers to millions of poor people hit by its lockdown. In neighbouring Pakistan, the government has announced a $6 billion plan to support the economy.

"The priority for all South Asian governments is to contain the virus spread and protect their people, especially the poorest who face considerable worse health and economic outcomes," said senior World Bank official Hartwig Schafer.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.