Category: Science & Tech

The rare green comet, which last visited Earth about 50,000 years ago, has returned to the skies. If the sky conditions are just right, C/2022 E3 (ZTF) can be seen with the naked eye.

What are Comets?

• Comets are frozen rocky or gas-filled objects that are remnants of the formation of the solar system.
• They tend to leave a light “behind them” due to their composition, characteristics, and movement path.
• The comet itself is green (called the comet’s head) and emits a whitish light behind it (often called the tail of the comet).
• Comets, like other celestial bodies, have orbits.
• Because of the sun’s gravity, they are sometimes drawn in close to the sun.
• As they approach the Sun, they heat up and spew gases and dust into a glowing head the size of a planet.
• To humans on Earth, the resulting dust trail looks like a trail of light from a distance.

What is Green Comet C/2022 E3 (ZTF)?

• Comet C/2022 E3 (ZTF) was discovered by the wide-field survey camera at the Zwicky Transient Facility in March of last year, when it was already inside Jupiter’s orbit.
• While initially thought to be an asteroid, it began to develop a tail as the Sun’s influence began to vapourise the ice.
• It was discovered with a magnitude of 17.3 when it was discovered.

Why is it green in colour?

• Comets have been observed emitting blue, whitish, or even green light.
• In this case, the green glow is thought to be caused by the presence of diatomic carbon – pairs of carbon atoms bound together – in the comet’s head.
• When excited by ultraviolet rays from solar radiation, the molecule emits green light.

When and where can you see the green comet?

• Northern Hemisphere observers will see the comet in the morning sky as it moves quickly toward the northwest during January.
• In early February, it will be visible in the Southern Hemisphere.
• When looking northwest in Indian skies, it can be found 16° above the horizon in the Bootes constellation.
• However, with the lights from buildings and streetlights on, it can be difficult to see without equipment.

Is the green comet uncommon?

• It last appeared in the skies above Earth during the Upper Paleolithic period, when Neanderthals roamed the planet and early Homo sapiens were just beginning to emerge.
• The green comet belongs to the category of long-period comets, which take more than 200 years to orbit the Sun.
• The comet’s highly elliptical orbit will take it back to the Oort cloud, where it will reappear roughly 50,000 years later.
• However, due to their orbits, it is not uncommon for comets to reappear close to Earth after many, many years.

Source: https://www.indiatoday.in/science/story/rare-green-comet-c2022-e3-ztf-reaches-earth-next-time-it-returns-humans-might-be-on-another-planet-2325809-2023-01-24#:~:text=By%20India%20Today%20Web%20Desk,the%20planet%20in%20its%20orbit.

NASA intends to launch a mission to Mars in 45 years using Bimodal Nuclear Propulsion.

Bimodal Nuclear Propulsion: What is it?

• A few years ago, NASA relaunched its programme to develop bimodal nuclear propulsion. Bimodal nuclear propulsion is a two-part system comprised of an NTP and a NEP component.
• This system is expected to allow Mars transits in 100 days.
• NASA Innovative Advanced Concepts (NIAC), a new programme launched by the US space agency in 2023, has chosen a nuclear concept for Phase I development.
• This new bimodal nuclear propulsion system will employ a “wave rotor topping cycle,” which has the potential to reduce transit times to Mars to 45 days.

How will nuclear propulsion work?

• Nuclear propulsion is divided into two categories: nuclear-thermal propulsion (NTP) and nuclear-electric propulsion (NEP) (NEP).
• The NTP system includes a nuclear reactor that will heat liquid hydrogen (LH2) propellant to create ionised hydrogen gas (plasma), which will then be channelled through nozzles to generate thrust.
• NEP is reliant on a nuclear reactor to power a Hall-Effect thruster (ion engine).
• It will produce an electromagnetic field that will ionise and accelerate an inert gas (such as xenon) to produce thrust.

Benefits offered

• Nuclear propulsion has significant advantages over traditional chemical propulsion.
• These advantages include increased fuel efficiency, a higher specific impulse rating, and infinite energy density (virtually).
• The advantage of NEP over NTP and conventional chemical propulsion systems is that it has a Specific impulse of more than 10,000 seconds (ISP).
• ISP measures how efficiently a reaction mass engine (a rocket that uses propellant or a jet engine that uses fuel) generates thrust.

Advantages of manned missions

• A crewed mission to Mars using traditional propulsion technology could take up to three years.
• A transit time of 45 days, on the other hand, reduces the overall mission time to months rather than years.
• This will significantly reduce the major risks associated with Mars missions, such as radiation exposure, time spent in microgravity, and related health concerns.

These nuclear propulsion systems have limitations.

• This means that NEP systems can sustain thrust for nearly three hours.
• However, when compared to conventional rockets and NTP systems, the thrust level is lower.
• Under ideal conditions, the thermal energy conversion rate in outer space is only 30-40%.

Source: https://timesofindia.indiatimes.com/gadgets-news/explained-how-nuclear-powered-rockets-can-send-missions-to-mars-in-45-days/articleshow/97176430.cms

Around the end of last year, Lensa-generated images of online users were trending on social media. Lensa, a subscription app, creates graphic portraits known as “Magic Avatar” images from selfies uploaded by its users. As AI gains a strong foothold in the realm of art, do we have mechanisms in place to define what is right and wrong in this domain in the first place?

The Lensa app case

• Lensa, a subscription app, creates graphic portraits known as Magic Avatar images from selfies uploaded by its users.
• Celebrities from around the world stepped in to demonstrate how they looked so perfect in their Lensa avatars.
• However, a few days later, hundreds of female netizens around the world began reporting problems with their avatars. They emphasised how their avatar images showed their waists snatched and sultry poses.
• Lensa generated hypersexualized, semi-pornographic images even after these women uploaded different pictures.

How does Artificial Intelligence generate art?

• Algorithms based on textual prompts are used: AI art refers to any form of art created using Artificial Intelligence. As the first step, it employs algorithms that learn a specific aesthetic based on textual prompts and then sift through vast amounts of data in the form of available images.
• Algorithms generate new images: The algorithm then attempts to generate new images that correspond to the aesthetics that it has learned.
• Artists’ roles with right keystrokes: The artist takes on the role of a curator, inputting the appropriate prompt to create an aesthetically pleasing output. While artists use brush strokes in other digital platforms such as Adobe Photoshop, keystrokes are all that is required in programmes such as Dall-E and Midjourney.
• For example, consider the digital generation of an artwork such as Starry Night. While it would have taken Van Gogh days to conceptualise and achieve the right strokes and paint, in the AI art era, it is simply a matter of the right textual prompts.

Is it truly capable of capturing the essence of humanity?

• The impact of AI-generation on the public’s perception of art: Art is one of the few activities that adds meaning to one’s life. It remains to be seen whether AI-generated art will alienate the masses from the art experience.
• AI takes away the joy of creating artwork: Artificial intelligence-generated art dehumanises artworks. Making an artwork is perhaps the most satisfying aspect of creating it.
• Concerns about AI’s ability to detect subtle human emotions: It is also questionable whether AI art will be able to capture the most subtle of human emotions. How much humour is considered “humorous” for AI? Can AI express grief and pain in the profound ways that our poets have described? Can artificial intelligence capture Mona Lisa’s enigmatic smile, which gives the impression that she is shrouded in mystery?

Arguments in favour of this type of art

• Midjourney generated Thatre D opera Spatial: Last year, when an entry called “Théâtre D’opéra Spatial” generated from Midjourney (an artificial intelligence programme) by Jason M Allen won the Blue Ribbon at the Colorado State Fair, the question of whether AI art is causing “a death of artistry” was raised.
• Finding appropriate prompts is a genius art: AI artists such as Allen believe that finding appropriate prompts to create an artwork constitutes creativity and qualifies AI art as genuine or authentic.
• AI has the potential to democratise the art world: Some artists believe that AI art has the potential to democratise the art world by removing gatekeepers.

Concerns about data biases

• There is bias in the data available for AI inputs due to a lack of representation of women, people of colour, and other marginalised groups in less privileged communities.
• The majority of training data for AI art is currently generated in the Global North and is frequently tainted by ableism, racism, and sexism stereotypes.
• Historically, art has served a political function by serving as a forum for dissent. Can AI art overcome data’s inherent biases to foster meaningful political engagement?

@the end

AI-generated art can introduce new ideas and possibilities to the art world, but it is important to consider how it may alter people’s perceptions of art and whether it eliminates the human touch. It is also worth considering whether AI can truly capture the emotions that make art so special. It’s best to approach AI-generated art with an open mind and consider both the positive and negative aspects.

Source: https://indianexpress.com/article/opinion/columns/ai-generated-art-human-biases-8399070/

A team of Indian scientists from the Indian Institute of Geomagnetism (IIG) reported the first evidence of the presence of solitary waves around Mars in a first-of-its-kind discovery.

What are Solitary Waves?

• Solitary waves are distinct (bipolar or monopolar) electric field fluctuations with constant amplitude-phase relationships.
• Their shape and size are less affected as they spread.
• Solitary waves are thought to be in charge of plasma energization and transport in the Earth’s magnetosphere.

Uncovering the hidden solitary waves

• The Earth is a massive magnetic entity encased in a magnetosphere created by the movement of molten iron in its core.
• This magnetosphere forms a protective layer around our home planet, shielding us from the Sun’s solar winds.
• However, unlike Earth, Mars lacks a strong intrinsic magnetic field, allowing the high-speed solar wind to interact directly with the Martian atmosphere.
• This interaction suggests that, even with a weak and flimsy magnetosphere, solitary waves on Mars are still a possibility.

Why is this a significant achievement for India?

• Despite several Mars missions, their presence was never detected — until now.
• Indian scientists, on the other hand, have successfully identified and reported the first-ever solitary waves detected on Mars.
• They arrived at this conclusion by analysing approximately 450 solitary wave pulses observed by NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft’s Langmuir Probe and Waves instrument.

Decoding the data

• Their analysis revealed distinct electric field fluctuations lasting between 0.2 and 1.7 milliseconds.
• Such signals were most common between dawn and dusk at altitudes ranging from 1000 to 3500 kilometres above Mars’ surface.
• More research is needed to determine why these waves are dominant at certain times of the day.

The importance of such waves on Mars

• These pulses are most visible at an altitude of 1000-3500 km around Mars in the dawn and afternoon dusk sectors.
• Researchers are investigating their role in particle dynamics in the Martian magnetosphere, as well as whether such waves contribute to the loss of atmospheric ions on Mars.
• The study of these waves is critical because wave-particle interactions directly control particle energization, plasma loss, transport, and so on.

Source: https://timesofindia.indiatimes.com/home/science/indian-scientist-led-team-first-to-find-evidence-of-solitary-waves-in-mars-magnetosphere/articleshow/97041561.cms

• ISRO stated that it has yet to receive approval from the Indian government for the Venus mission, and that the mission may be delayed until 2031 as a result.

Shukrayaan I: Venus Orbiter Mission

• Shukrayaan-I is an Indian Space Research Organization (ISRO) planned Venus orbiter to study the planet’s surface and atmosphere.
• The concept was born in 2012, and five years later, ISRO began preliminary research after the Department of Space received a 23% increase in the 2017-2018 budget.
• Depending on its final configuration, the orbiter could carry up to 100 kilogrammes (220 lb) of science payload and have 500 W of available power.
• The launch will involve GSLV Mark II.

Anticipated launch date

• ISRO had hoped to launch Shukrayaan I in mid-2023, but due to the pandemic, the date was pushed back to December 2024.
• Optimal launch windows from Earth to Venus occur every 19 months or so.
• This is why ISRO has ‘backup’ launch dates in 2026 and 2028 in case the 2024 opportunity is missed.
• However, even more optimal windows that reduce the amount of fuel required at liftoff occur every eight years.

Other Venus missions

• Venus missions, referred to as VERITAS and EnVision, are planned for 2031 by the US and European space agencies, respectively.

Source: https://www.thehindu.com/sci-tech/science/isro-pushing-venus-mission-shukrayaan-to-2031/article66382110.ece#:~:text=In%20a%20talk%20on%20January,a%20result%20be%20postponed%20to

Circulations of the Indian Ocean Studies have shown that tectonically driven changes in ocean gateways, such as the closure of the Central American Seaway, a body of water that once separated North America from South America, have had a dramatic impact on Indian Ocean circulation since the late Miocene period.

Global overturning circulation (GOC)

• It is the transport of cold, deep waters equatorward and warm, near-surface waters poleward.
• It regulates ocean heat distribution and atmospheric CO2 levels, and thus plays an important role in global climate.

Concept: Panama Closure Hypothesis

• This article focuses on the Panama Closure Hypothesis.
• According to the Panama Hypothesis, the gradual closure of the Panama Seaway between 13 million years ago (13 Ma) and 2.6 Ma resulted in less mixing of Atlantic and Pacific water masses.
• As a result, the North Atlantic Deep water circulation formed.
• It boosted the Atlantic thermohaline circulation, increased North Atlantic temperatures and evaporation, and increased precipitation in Northern Hemisphere high latitudes.

The Effects of the Panama Canal Closure

• Tectonic changes are thought to have resulted in the formation of two distinct water bodies: northern component water in the North Atlantic and Antarctic Bottom Water (AABW) in the Southern Ocean.
• As a result, it is also hypothesised that large-scale changes in Deep Water Circulation (DWC) in the world’s oceans would have occurred.
• The impact on the Indian Ocean gyre
• The Indian Ocean lacks major deep-water formations of its own.
• It only serves as a host for NCW and AABW.
• Furthermore, the northern Indian Ocean is located at one of the GOC’s terminal ends, far from deep-water formation regions and oceanic seaways.

New research findings

• The researchers created an authigenic neodymium isotope record from the Arabian Sea and reconstructed the Indian Ocean’s DWC record from 11.3 million years ago (Miocene era) to 1.98 million years ago (Pleistocene era).
• The record shows a clear shift from a Pacific water-dominated deep circulation system to the emergence of a modern-like deep water circulation system in the Indian Ocean around nine million years ago.
• During the Miocene-Pliocene transition, it was composed of Antarctic bottom water and northern component water (about six million years ago).
• This suggests that the late Miocene Central American Seaway closure had a widespread impact on the evolution of ocean deep water circulation and validates the so-called Panama Closure Hypothesis.

Back2Basics: Indian Ocean Circulation

• The Indian Ocean circulation/gyre is one of the five major oceanic gyres, which are large systems of rotating ocean currents that form the backbone of the global conveyor belt.
• The South Equatorial Current and the West Australian Current are the two major currents that make up the Indian Ocean gyre.
• The Indian Ocean gyre, which normally moves counter-clockwise, reverses direction in the winter due to the seasonal winds of the South Asian Monsoon.

How does it function?

• In the summer, the land is warmer than the ocean, so surface winds blow from the ocean to the land.
• During the winter, however, these temperatures reverse, causing winds to blow from the land to the sea.
• Air pressure gradients over the Indian Ocean and the gyre are small because the majority of the air pressure gradient is retained behind the Tibetan plateau.
• As a result of the protection from the full-force winds blowing off the Mongolian high-pressure region, winds of moderate strength prevail.
• The Winter Monsoon season in the Indian Ocean region is the dry season for most of Southern Asia due to these moderate, dry winds.
• The Indian Ocean currents, which comprise the Indian Ocean gyre, are directly affected by this seasonal wind cycle, causing reversal.

Source: https://www.thehindu.com/sci-tech/reconstructing-past-deep-water-circulations-of-indian-ocean/article66377125.ece