Current Affairs October 31, 2021


  • They have studied a meteorite that fell near the town of Katol in Nagpur District of Maharashtra on May 22, 2012, reporting for the first time, presence of veins of the mineral bridgmanite, which is the most abundant mineral in the interior of the Earth, within the Katol L6 Chondrite meteorite.
  • This finding adds evidence to the Moon-forming giant impact hypothesis. Abundant mineral “Bridgmanite is the most volumetrically abundant mineral of the Earth’s interior.
  • It is present in the lower mantle (from 660 to 2700 km), and it is important to understand its formation mechanism to better comprehend the origin and evolution of planetary interiors
  • The Moon-forming giant impact hypothesis is that long ago, nearly 4.5 billion years ago, the Earth collided with a planet the size of Mars named Thela, and the force of this impact was so huge as to melt the Earth down from the surface to a depth of 750 km to 1,100 km.
  • “Earth was an ocean of magma in the past. The heavier iron and nickel went to the core while the lighter silicates stayed in the mantle.
  • By studying the meteorite, we can understand more details about the formation of the Earth and other planets.
  • “Bridgmanite consists of magnesium, iron, calcium aluminum oxide and has a perovskite structure”
  • He further explains that while the crystal structure of natural bridgmanite has been reported in other meteorites such as the Tenham and Suizhou meteorites, their chemical composition does not fully match with the terrestrial bridgmanite present in the Earth’s interior between 660 and 2700 km depth.
  • “Our findings led to numerous other advances to understand how the Earth’s core formed about 4.5 billion years ago,”


Relay planting and strip cropping

  • “Integrated farming with intercropping increases food production while reducing environmental footprint”
  • “Relay planting” enhances yield,
  • within-field rotation or “strip rotation”, allowing strips for planting other plants (such as grass, fruits) besides the major crop was more fruitful,
  • “Soil munching,” that is, available means such as crop straw, in addition to the major crop such as wheat or rice
  • “No-till” or a reduced tillage, which increases the annual crop yield up by 15.6% to 49.9%, and decreasing the environmental footprint by 17.3%, compared with traditional monoculture cropping.
  • This led to the conclusion that small farm holders can grow more food and have reduced environmental footprint.
  • Relay planting means the planting of different crops in the same plot, one right after another, in the same season.
  • Examples of such relay cropping would be planting rice (or wheat), cauliflower, onion, and summer gourd (or potato onion, lady’s fingers and maize), in the same season .It also means better distribution of labour, insects spread less, and any legumes actually add nitrogen to the soil
  • Strip cropping is a method of farming used when a slope is too steep or too long, or otherwise, when one does not have an alternative method of preventing soil erosion.
  • The practice has been widespread in North America as a means of mitigating soil erosion from wind and water.
  • Strip cropping has been used in the U.S. (where the fields are larger than those in India), where they grow wheat, along with corn and soybean, in the same farm in an alternative manner.
  • However, this needs large lands. In India, where there are large fields (such as the ones owned by cities and state governments), the land is divided into strips, and strips of grass are left to grow between the crops.
  • Planting of trees to create shelters has helped in stabilising the desert in Western India.


Nunavut and polar bear

  • Monitoring what polar bears eat can reveal facts about environmental shifts and distribution of marine mammal prey. Researchers found by harvest-based sampling of polar bear in the Nunavut region that these were, in fact, flexible eaters, making them ideal as a monitoring tool to track environmental changes in the Arctic
  • Nunavut is a massive, sparsely populated territory of northern Canada, forming most of the Canadian Arctic Archipelago. Its islands have expanses of tundra, craggy mountains and remote villages, accessible only by plane or boat. It’s known for its indigenous Inuit people’s artwork, carvings and handmade clothing.


Banded appearance in Jupiter

  • Jupiter is known for its banded appearance white strips known as zones and darker, reddish ones, belts.
  • Using microwave radiometers, Juno probe discovered that the appearance (brightness) of Jupiter’s belts and zones inverts near the base of the clouds.
  • Since the brightness relates to either warmth of the atmosphere or presence of ammonia, researchers believe either of these parameters inverts as you go deep into the atmosphere of Jupiter.

About Juno mission

  • Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is operated by NASA’s Jet Propulsion Laboratory.
  • The spacecraft was launched from Cape Canaveral Air Force Station on 5 August 2011 UTC, as part of the New Frontiers program.
  • Juno entered a polar orbit of Jupiter on 5 July 2016 UTC, to begin a scientific investigation of the planet.
  • After completing its mission, Juno will be intentionally deorbited into Jupiter’s atmosphere. Juno’s mission is to measure Jupiter’s composition, gravitational field, magnetic field, and polar magnetosphere. It will also search for clues about how the planet formed, including whether it has a rocky core, the amount of water present within the deep atmosphere, mass distribution, and its deep winds, which can reach speeds up to 620 km/h (390 mph).
  • Juno is the second spacecraft to orbit Jupiter, after the nuclear powered Galileo orbiter, which orbited from 1995 to 2003.
  • Unlike all earlier spacecraft sent to the outer planets, Juno is powered by solar panels, commonly used by satellites orbiting Earth and working in the inner Solar System, whereas radioisotope thermoelectric generators are commonly used for missions to the outer Solar System and beyond. For Juno, however, the three largest solar panel wings ever deployed on a planetary probe play an integral role in stabilizing the spacecraft as well as generating power.


  • New research, led by University of Cambridge researchers, published in Science Advances, finds a different route to Alzheimer’s.
  • Rather than originating in a single point and spreading as a chain and killing brain cells, they found that the disease reaches different points early on.
  • The progress of the disease depends on how quickly it kills these cells.
  • The researchers used post mortem brain samples and also PET scans of living patient
  • Positron emission tomography is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption.



  • Facebook CEO Mark Zuckerberg announced the rebranding of his company to Meta.
  • The change, he said in a post, has been brought about “to reflect who we are and the future we hope to build”.
  • It is called metaverse (thus the new name). Metaverse is what the Facebook founder calls “an embodied internet”.
  • It is where “you’re in the experience, not just looking at it”.


  • Shows him being called in to join his friend’s playing cards in a virtual space.
  • They are all there as their chosen avatars, one of them even floating around the virtual room.
  • They hide or reveal their cards just as they would in a real setting. He then dials another friend, who talks about an artist who is hiding augmented reality art pieces on street walls for people to find.
  • The friends in the virtual space get sent the link of this art and view it then and there. Metaverse, for him, marks an evolution of how people connect with each other
  • Metaverse as a successor to the mobile internet and as something that will see contributions from many companies.
  • Metaverse is a virtual environment that will lend itself to immersive experiences.
  • It means, according to Mr. Zuckerberg, “having a shared sense of space and not just looking at a grid of faces”.
  • The “defining quality of the metaverse” is the feeling of presence.
  • Privacy is an area of concern because in an immersive environment, such as metaverse, a lot more of one’s personality and information will be revealed.
  • Social media platforms, like Facebook, essentially make their money through targeted advertisements.