>>21049252

Will be a good opportunity to get everyone watching thinking bigger.

NASA Astronomy Picture of the Day

June 19, 2024

NGC 6188: Dragons of Ara

Do dragons fight on the altar of the sky? Although it might appear that way, these dragons are illusions made of thin gas and dust. The emission nebula NGC 6188, home to the glowing clouds, is found about 4,000 light years away near the edge of a large molecular cloud, unseen at visible wavelengths, in the southern constellation Ara (the Altar). Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions from previous generations of massive stars, that swept up and compressed the molecular gas. This impressively detailed image spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance of NGC 6188.

https://apod.nasa.gov/apod/astropix.html?

NASA Updates Coverage for US Spacewalks 90, 91 Outside Space Station

JUN 18, 2024

NASA will provide live coverage as astronauts conduct two spacewalks outside the International Space Station scheduled for Monday, June 24 and Tuesday, July 2.

The first spacewalk is scheduled to begin at 8 a.m. EDT June 24, and last about six and a half hours. NASA will provide live coverage beginning at 6:30 a.m.

NASA will stream the spacewalk on NASA+, NASA Television’s public channel, the NASA app, YouTube, and the agency’s website. Learn how to stream NASA TV through a variety of platforms including social media.

NASA astronauts Tracy C. Dyson and Mike Barratt will exit the station’s Quest airlock to complete the removal of a faulty electronics box, called a radio frequency group, from a communications antenna on the starboard truss of the space station. The pair also will collect samples for analysis to understand the ability of microorganisms to survive and reproduce on the exterior of the orbiting laboratory.

Dyson will serve as spacewalk crew member 1 and will wear a suit with red stripes. Barratt will serve as spacewalk crew member 2 and will wear an unmarked suit.

U.S. spacewalk 90 will be the fourth spacewalk for Dyson and the third spacewalk for Barratt. It is the 271st spacewalk in support of space station assembly, maintenance, and upgrades.

U.S. spacewalk 90 was initially scheduled for June 13 but did not proceed as scheduled because of a spacesuit discomfort issue.

The second spacewalk is scheduled to begin at 9 a.m. July 2, and last about six and a half hours.

NASA will provide live coverage beginning at 7:30 a.m. Astronauts will remove and replace a gyroscope assembly, relocate an antenna, and prepare for future Alpha Magnetic Spectrometer upgrades.

NASA will stream the spacewalk on NASA+, NASA Television’s public channel, the NASA app, YouTube, and the agency’s website.

Following the completion of U.S. spacewalk 90, NASA will provide an update with participating crew members for U.S. spacewalk 91. It is the 272nd spacewalk in support of space station.

https://www.nasa.gov/news-release/nasa-updates-coverage-for-us-spacewalks-90-91-outside-space-station/

Perseverance Finds Popcorn on Planet Mars

JUN 18, 2024

After months of driving, Perseverance has finally arrived at ‘Bright Angel’, discovering oddly textured rock unlike any the rover has seen before.

The team now plans to drive up the slope to uncover the origin of this rock sequence and its relationship to the margin unit.

Having completed a survey of the intriguing and diverse boulders at 'Mount Washburn,’ the rover headed north, parking just in front of an exposure of layered light toned rock.

This provided the team with our first close-up look of the rocks that make up the ‘Bright Angel’ exposure, so Perseverance stopped to acquire images, before driving west to a larger and more accessible outcrop where the rover will conduct detailed exploration.

Perseverance arrived at the base of this outcrop on sol 1175, and geologists on the science team were mesmerized by the strange textures of the light toned rocks found there.

These rocks are filled with sharp ridges that resemble the mineral veins found at the base of the fan, but there appears to be more of them here. Additionally, some rocks are densely packed with small spheres, and we’ve jokingly referred to this as a ‘popcorn’-like texture.

Together, these features suggest that groundwater flowed through these rocks after they were laid down. Next, Perseverance will gradually ascend up the rock exposure, taking measurements as it goes.

Over the weekend, the abrasion tool will be used to take a close-up look and acquire detailed chemical information using the instruments on the rover’s arm. With this data in hand, the team will decide whether or not to sample.

Once our exploration at ‘Bright Angel’ is complete, we will drive south back across Neretva Vallis and explore a site called ‘Serpentine Rapids’.

https://science.nasa.gov/blogs/perseverance-finds-popcorn-on-planet-mars/

Nine killed, 46 injured in Chad's capital after ammunition depot explosions

June 19, 2024, 4:51 AM PDT

Nine people were killed and more than 40 injured when a fire set off explosions at a military ammunition depot in Chad’s capital, a government spokesperson said Wednesday.

Spokesperson Abderaman Koulamallah said 46 people are being treated for various injuries after the explosions in the Goudji district of the capital, N’Djamena.

Local media reported the blasts started just before midnight Tuesday and lasted more than 30 minutes as nearby buildings shook and ammunition was thrown from the depot with explosive force.

Explosions and fire at a military ammunition depot in Chad’s capital caused fatalities and set off frantic efforts to put out the fire and treat the wounded, authorities and witnesses said Wednesday.

The explosions late Tuesday at the depot in N’Djamena lit up the sky as thick smoke covered the clouds in the West African nation.

The fire “caused human and material damage,” President Mahamat Deby Itno posted on Facebook. “Peace to the souls of the victims, sincere condolences to the bereaved families and quick recovery to the injured.”

He did not give the number of fatalities.

The cause of the fire was not immediately clear, and the president said an investigation would be conducted.

People living in the area panicked, thinking the explosion was an armed attack, resident Oumar Mahamat said.

The situation was later brought under control with security and health officials deployed in the area, government spokesperson Abderaman Koulamallah said. He urged residents to remain calm.

Local media reported the blasts started just before midnight and lasted more than 30 minutes as nearby buildings shook and ammunition was thrown from the depot with explosive force.

Authorities called on residents to stay out of the area, which was taken over by security forces gathering the scattered artillery shells.

Allamine Moussa, a resident, called on the government to “come to our aid urgently” after he and other residents fled their homes.

“Many families have recorded deaths and it’s sad,” Moussa said.

Chad, a country of nearly 18 million people, has been reeling from political turmoil before and after a controversial presidential election that resulted in Deby Itno’s victory.

He had led the country as interim president during the period of military rule that followed the death of his father in 2021.

The explosion might not be entirely coincidental and “feels more like a message” to the government in Chad, which has been embroiled in both an internal political crisis with the recent election as well as regional tensions with the war in neighboring Sudan, according to Cameron Hudson, an Africa expert at the Center for Strategic and International Studies.

Recent claims about Chad’s alleged involvement put the country “on both sides of the war in Sudan and creates an untenable position at home for Deby,” said Hudson, a former U.S. official. “A house divided cannot stand.”

https://www.nbcnews.com/news/world/chad-explosions-kill-nine-rcna157900

NASA Satellites Find Snow Didn’t Offset Southwest US Groundwater Loss

JUN 17, 2024

Record snowfall in recent years has not been enough to offset long-term drying conditions and increasing groundwater demands in the U.S. Southwest, according to a new analysis of NASA satellite data.

Declining water levels in the Great Salt Lake and Lake Mead have been testaments to a megadrought afflicting western North America since 2000.

But surface water only accounts for a fraction of the Great Basin watershed that covers most of Nevada and large portions of California, Utah, and Oregon.

Far more of the region’s water is underground. That has historically made it difficult to track the impact of droughts on the overall water content of the Great Basin.

A new look at 20 years of data from the Gravity Recovery and Climate Experiment (GRACE) series of satellites shows that the decline in groundwater in the Great Basin far exceeds stark surface water losses.

Over about the past two decades, the underground water supply in the basin has fallen by 16.5 cubic miles (68.7 cubic kilometers).

That’s roughly two-thirds as much water as the entire state of California uses in a year and about six times the total volume of water that was left in Lake Mead, the nation’s largest reservoir, at the end of 2023.

While new maps show a seasonal rise in water each spring due to melting snow from higher elevations, University of Maryland earth scientist Dorothy Hall said occasional snowy winters are unlikely to stop the dramatic water level decline that’s been underway in the U.S. Southwest.

The finding came about as Hall and colleagues studied the contribution of annual snowmelt to Great Basin water levels.

“In years like the 2022-23 winter, I expected that the record amount of snowfall would really help to replenish the groundwater supply,” Hall said.

“But overall, the decline continued.” The research was published in March 2024 in the journal Geophysical Research Letters.

“A major reason for the decline is the upstream water diversion for agriculture and households,” Hall said.

Populations in the states that rely on Great Basin water supplies have grown by 6% to 18% since 2010, according to the U.S. Census Bureau. “As the population increases, so does water use.”

Runoff, increased evaporation, and water needs of plants suffering hot, dry conditions in the region are amplifying the problem. “With the ongoing threat of drought,” Hall said, “farmers downstream often can’t get enough water.”

While measurements of the water table in the Great Basin — including the depths required to connect wells to depleted aquifers — have hinted at declining groundwater, data from the joint German DLR-NASA GRACE missions provide a clearer picture of the total loss of water supply in the region.

The original GRACE satellites, which flew from March 2002 to October 2017, and the successor GRACE–Follow On (GRACE–FO) satellites, which launched in May 2018 and are still active, track changes in Earth’s gravity due primarily to shifting water mass.

GRACE-based maps of fluctuating water levels have improved recently as the team has learned to parse more and finer details from the dataset.

“Improved spatial resolution helped in this study to distinguish the location of the mass trends in the Western U.S. roughly ten times better than prior analyses,” said Bryant Loomis, who leads GRACE data analysis at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The diminishing water supplies of the U.S. Southwest could have consequences for both humans and wildlife, Hall said.

In addition to affecting municipal water supplies and limiting agricultural irrigation, “It exposes the lake beds, which often harbor toxic minerals from agricultural runoff, waste, and anything else that ends up in the lakes.”

In Utah, a century of industrial chemicals accumulated in the Great Salt Lake, along with airborne pollutants from present-day mining and oil refinement, have settled in the water.

The result is a hazardous muck that is uncovered and dried as the lake shrinks. Dust blown from dry lake beds, in turn, exacerbates air pollution in the region.

Meanwhile, shrinking lakes are putting a strain on bird populations that rely on the lakes as stopovers during migration.

According to the new findings, Hall said, “The ultimate solution will have to include wiser water management.”

https://www.nasa.gov/science-research/earth-science/nasa-satellites-find-snow-didnt-offset-southwest-us-groundwater-loss/

>>21049928

The orange paint almost looks a little golden

Monitoring marine litter from space is now a reality

19/06/2024

The quantity of plastic floating on the sea surface is rarely high enough to generate a detectable signal from space.

Plastics and other floating debris have to accumulate into dense patches of at least tens of metres in area to be detectable using existing satellites.

These patches of floating litter are called ‘slicks’, ‘streaks’ or ‘litter windrows’. They are often filament-shaped, resulting from the presence of convergence current lines on the sea surface.

Detecting such litter windrows is indicative of high pollution at a particular place and time. But could such scattered and short-lived patches of litter provide sufficiently useful data for global monitoring of plastic pollution?

“We didn’t know if the abundance of litter windrows was enough to draw maps, or to reveal trends over time,” notes Andrés Cózar, from the University of Cádiz, co-director of the project.

To find out ESA Discovery funded a consortium of space companies and research institutes from six countries.

Using a six-year historical series of 300 000 satellite images, the team scanned the entire Mediterranean Sea every three days, at a spatial resolution of 10 metres, on the hunt for windrows.

They relied on the multispectral imaging Sentinel-2 satellites of Europe’s Copernicus programme, which while not designed for litter detection, have a somewhat limited capability for plastic detection.

“Searching for litter aggregations of metres in size on the ocean surface is like looking for needles in a haystack,” explains Manuel Arias, from the Institute of Marine Sciences, CSIC, in Spain, the other project co-director.

Automation was what made the project possible, harnessing supercomputers and advanced search algorithms. The team found thousands of litter windrows, most more than a kilometre long – and some reaching 20 km in length.

The result was the most complete map of marine litter pollution to date.

“Litter detections with a non-specialised satellite allowed us to identify the most polluted areas and their major changes over weeks and years,” comments Andrés Cózar. “Litter is injected into the Mediterranean Sea as the rainstorms rage.”

A key element of this work has been in understanding the significance of the litter windrow structures in the context of marine monitoring, being mainly associated with land-based litter emissions in the preceding days.

This makes them especially useful for surveillance and management of the problem.

In the paper the team assess the effectiveness of action plans against marine litter around Rome, identify a pollution hotspot related to shipping through the Egypt’s Suez Canal and put forward satellite data for guiding cleanup operations in Spain’s Bay of Biscay.

Manuel Arias explains: “The tool is ready to be used in other world regions, which I am convinced will teach us much about the littering phenomenon, including identification of sources and the pathways to the ocean.”

Andrés Cózar adds: “There is still room for improvement. The sensor used in our proof was not designed to detect plastic. Detection capability would be enormously improved if we put observation technology into orbit tailored for ocean plastics.”

The ability to monitor marine litter pollution in this way also holds broader promise. The deployment of a sensor specifically dedicated to detect and identify floating objects one metre in size could also be useful for tasks such as oil spill monitoring, loss of cargo or even search and rescue at sea.

Paolo Corradi, overseeing the project for ESA Discovery, comments: “The importance of these results and the applicability of this methodology can indeed be extended in a wider sense to the monitoring and characterisation of generic floating matter accumulations.

This could be the more general target of a dedicated small satellite mission, which would collect the interest of a large scientific community, while addressing the need for large scale monitoring of marine litter pollution.”

“ESA Discovery is our funding programme to ensure our Agency is ready for tomorrow, looking into future ways we might make use of space,” comments Dietmar Pilz, ESA Director of Technology, Engineering and Quality.

“The potential detection of marine plastic litter has been a topic of interest for a number of years within ESA Discovery. I am pleased to see this work has resulted in such a landmark scientific paper, exploiting the incredible value of the data from Europe’s Copernicus satellites.”

https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Monitoring_marine_litter_from_space_is_now_a_reality