UPSC Daily Current Affairs | Prelim Bits 23-08-2024

Toxic mercury in Arctic’s permafrost

As the Arctic’s permafrost thaws in a warming climate, an enormous amount of toxic mercury is being released into the environment.

• Permafrost – They are any ground that remains completely frozen 32°F (0°C) or colder—for at least two years straight.
• Permafrost is made of a combination of soil, rocks and sand that are held together by ice.
• These are most common in regions with high mountains and in Earth’s higher latitudes—near the North and South Poles.

• Active layer – It is the top layer of the permafrost that does not stay frozen all year.
• It thaws during the warm summer months and freezes again in the fall.
• Permafrost Thawing - As Earth’s climate warms, the ice inside the permafrost melts, leaving behind water and soil.
• Mercury Bomb - A significant amount of total mercury (THg) is liberated from permafrost during glacial erosion in Arctic.
• Abrupt thawing events can rapidly mobilise metres-thick deposits of sediment, potentially releasing large mercury.
• The mercury content was generally higher in sediment, with finer rather than coarser grains
• Thaw slumps – It is a type of landslide that occurs in the terrestrial Arctic’s permafrost region.
• Thaw slumps adjacent rivers around the arctic region - Mackenzie river, Yukon and Koyukuk rivers, elevate suspended particulate mercury contents downstream.
• Most mercury eroded from the banks during river migration is redeposited with sediments.
• Arctic Mercury - Mercury is a global environmental contaminant with both natural sources and sources associated with human activities.
• Much of the mercury contaminating the Arctic is a result of transport by air and ocean pathways from sources outside of the Arctic.
• Over 98% of atmospheric mercury is emitted outside the region and is transported to the Arctic via long-range air and ocean transport.
• Impact - People and wildlife living in the Arctic are some of the most exposed human populations globally to mercury.
• Mercury is a neurotoxin that can cause serious harm to the brain and nervous system, particularly when it accumulates in the food chain.
• Many indigenous communities, including Alaskan communities, rely on subsistence fishing and have disproportionately elevated blood mercury levels linked to dietary exposure.

References

Down to Earth |Toxic mercury trapped in Arctic’s permafrost

Kodaikanal Tower Tunnel Telescope

Scientists have discovered a new method to explore the Sun's secrets by studying magnetic fields at different layers of its atmosphere using data from the Kodaikanal Tower Tunnel Telescope.

References

1. PIB | Kodaikanal Tower Tunnel Telescope
2. India Today | Kodaikanal Tower Tunnel Telescope

Island of Madeira

Wildfires in Madeira have endangered world-heritage forests and stranded tourists, with nearly 6% of the island's total area burned.

Reference

Down to Earth | Island of Madeira

Underground Ocean on Ariel

The scientists using the James Webb Space Telescope have detected carbon dioxide ice on Uranus' moon Ariel, marking a key discovery in the search for water in the solar system.

• Scientists working on the “Moons of Uranus” project has been closely studying 4 specific moons orbiting Uranus in order to find traces of ammonia, organic molecules, water, or carbon dioxide ice.
• They found that carbon dioxide ice was present on the surface of Uranus’ moon called Ariel.
• Potential Underground Ocean- The presence of carbon dioxide ice on Ariel suggests there may be a liquid ocean beneath its surface.
• Possible Chemical Processes- The underground ocean may be releasing carbon dioxide through chemical processes, which then escapes to the surface via ice cracks.
• Another theory suggests that Uranus' magnetic field could be breaking down molecules to generate carbon dioxide.
• Additional Findings- Carbon monoxide and traces of carbonates were also found on Ariel’s surface. Carbonates are typically formed when water interacts with rocks.
• Significance- Underground oceans are considered important in the search for extra-terrestrial life, as they may harbour or sustain life.

References

1. India Express | underground ocean on Uranus’ moon
2. Brittanica | Ariel

JUICE probe

European scientists were due to attempt a first in orbital gymnastics tapping into the gravity of the earth.

• JUICE probe- The Jupiter Icy Moons Explorer (JUICE) probe.
• It is a European Space Agency (ESA) mission designed to explore Jupiter and its 3 large moons i.e. Callisto, Europa, and Ganymede.
• Launched in - April, 2023, aboard an Ariane 5 rocket from the Guiana Space Centre.
• Goals
  • Exploring the moons - Create detailed maps of the moons' surfaces, analyze the water bodies beneath them, and characterize them as planetary objects and potential habitats
  • Studying Jupiter - Monitor Jupiter's magnetic, radiation, and plasma environment, and understand its origin, history, and evolution
  • Searching for life - Investigate the possibility of life in space by studying the moons' subsurface oceans, which are believed to have conditions that could support life.

Gravity assist

• It is a technique where a spacecraft brushes past a planet or moon, using its gravity to alter speed or trajectory.
• Scientists will tapping into the gravity of the earth to guide the JUICE probe towards Jupiter in the first-ever double slingshot manoeuvre.
• In a novel double manoeuvre, the JUICE probe will first use the gravity of the moon to swing towards the earth on exactly the right trajectory.
• If successful, it will put JUICE on course to reach Jupiter and its 3 large ocean-bearing moons - Callisto, Europa and Ganymede in 2031 with the help of three further single gravity assists
  • Venus in 2025, and then
  • The earth again in 2026 and 2029.

References

1. The Hindu | Juice Probe
2. ESA | Juice spacecraft specs