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
March 31,2020

Months after the outbreak of COVID-19 in Wuhan city of central China, families of those deceased, who contracted the contagious infection, stood in long queues at funeral homes demanding to receive the cremated ashes of their loved ones.

Now this has spurred questions about the actual tally of COVID-19 related casualties in Wuhan, in a renewed pressure on the Chinese government that is already struggling to control its containment narrative of the pandemic spread.

Chinese media outlet Caixin showed how trucks carrying 2,500 urns with the ashes of the deceased COVID-19 cases were being shipped in a funeral home last week. Another picture published revealed how 3,500 urns were stacked within these funeral homes. It is therefore unclear how many urns have been filled in.

According to media reports, workers at several funeral parlors declined to provide any details as to how many urns were waiting to be collected, saying they either did not know or were not authorised to share the number.

Some families said they had been forced to wait for several hours to pick up the ashes. The photos circulated as mass deaths from the virus spiked in cities across the west, including Milan, Madrid and New York, where hospitals were erecting tents to handle the overflow as global infections soar past 500,000, with 24,000 dead.

According to Chinese government figures, 2,535 people in Wuhan have died of the virus. The announcement that a lockdown in place since January would be lifted came after the country said its tally of new cases had hit zero and stepped up diplomatic outreach to other countries hard hit by the virus, sending some of them medical supplies.

But some in China have been skeptical of the accuracy of the official tally, particularly given Wuhan's overwhelmed medical system, authorities' attempts to cover up the outbreak in its initial stages, and multiple revisions to the way official cases are counted.

Residents on social media have demanded disciplinary action against top Wuhan officials.

Many people who died had Covid-19 symptoms, but weren't tested and excluded from the official case tally, Caixin said. There were also patients who died of other diseases due to a lack of proper treatment when hospitals were overwhelmed dealing with those who had the coronavirus.

There were 56,007 cremations in Wuhan in the fourth quarter of 2019, according to data from the city's civil affairs agency. The number of cremations was 1,583 higher than those in the fourth quarter of 2018 and 2,231 higher than the fourth quarter of 2017.

Two locals in Wuhan who have lost family members to the virus said online that they were informed they had to be accompanied by their employers or officials from neighborhood committees when picking up the urns, likely as a measure against public gatherings.

COVID-19 is affecting 199 countries and territories around the world. Over 664,000 coronavirus cases have been registered globally out of which 30,890 have succumbed to the infection.

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News Network
March 21,2020

United Nations, Mar 21: The UN has called on all nations to stop the use of capital punishment or put a moratorium on it, a day after four men convicted of gang-raping and murdering a 23-year-old woman were hanged in India.

Seven years after the rape and murder of the young medical student, who came to be known as 'Nirbhaya', sent shock waves across the country, the four convicts - Mukesh Singh (32), Pawan Gupta (25), Vinay Sharma (26) and Akshay Kumar Singh (31) - were hanged to death on Friday at 5.30 am in New Delhi's Tihar Jail.

Responding to the hanging, UN Secretary-General Antonio Guterres' spokesperson Stephane Dujarric said the world organisation calls on all nations to stop the use of capital punishment or put a moratorium on it.

"Our position has been clear, is that we call on all States to halt the use of capital punishment or at least put a moratorium on this," Dujarric said at the daily press briefing on Friday.

The horrific gang-rape and murder of the physiotherapy intern on December 16, 2012, who came to be known as Nirbhaya, the fearless, had seared the nation's soul and triggered countrywide outrage.

This was the first time that four men have been hanged together in Tihar Jail, South Asia's largest prison complex that houses more than 16,000 inmates.

The executions were carried out after the men exhausted every possible legal avenue to escape the gallows. Their desperate attempts only postponed the inevitable by less than two months after the first date of execution was set for January 22.

The execution of the four convicts brings the curtains down on the case that shook not just India but also the world with the details of its brutality The widespread protests subsequently paved the way for a change in India's rape laws.

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News Network
May 20,2020

Washington, May 20: The United States recorded another 1,536 coronavirus deaths over the past 24 hours, the Johns Hopkins University tracker said.

That figure, tallied as of 8:30 pm (0030 GMT), raises to 91,845 the total number of COVID-19 deaths in the US.

The US tops the global rankings both for the highest death toll and the highest number of infections, with more than 1.5 million cases.

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