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Subject: Space Technology

  • Valentina Tereshkova: The First Woman in Space

    Why in the News?

    On June 16, 1963, Valentina Tereshkova made history as the first woman to venture into space. Her achievement marked a significant milestone in the Space Race between the USA and the USSR during the Cold War.

    About Valentina Tereshkova’s Space Journey

    • In 1962, Tereshkova was selected among five women for the Soviet space program, aiming to achieve ‘gender equality’ in space exploration.
    • The USSR’s decision to send a woman into space was partly influenced by the success of Yuri Gagarin’s mission in 1961 and the desire to surpass the US in space achievements.
    • Tereshkova’s affiliation with the Communist Party and her skills as a parachutist were factors in her selection for the Vostok 6 mission.

    The Mission – Vostok 6

    • On June 16, 1963, Tereshkova piloted Vostok 6, becoming the first woman to orbit the Earth.
    • She spent 71 hours in space, completing 48 orbits around the Earth during her mission.

    Impact and Legacy

    • Tereshkova’s mission boosted Soviet prestige in the Space Race, following earlier successes like launching Sputnik-1 in 1957 and Yuri Gagarin’s historic flight in 1961.
    • Despite her pioneering role, the USA would later achieve milestones like the Apollo moon landings, surpassing Soviet achievements in manned space missions.
    • Tereshkova continued to advocate for women’s participation in space exploration and held prominent positions in Soviet politics and the Air Force.

    Indian Women in Space 

    Indian women have made significant contributions to space exploration, marking milestones and inspiring future generations. Here are notable Indian women who have ventured into space:

    • Kalpana Chawla: Born in Karnal, Haryana, Kalpana Chawla was the first woman of Indian origin in space. She flew on two Space Shuttle missions, including STS-87 in 1997. Tragically, she lost her life during the re-entry of the Space Shuttle Columbia in 2003.
    • Sunita Williams: An American astronaut of Indian-Slovenian descent, Sunita Williams has set records for spacewalks and served as a flight engineer on the International Space Station (ISS). She has logged over 322 days in space across multiple missions.
    • Sirisha Bandla: An aeronautical engineer and Vice President at Virgin Galactic, Sirisha Bandla became the second India-born woman to travel to space on the Virgin Galactic Unity 22 mission in 2021.

    Women Pioneers of ISRO:

    • Lalitha Ramachandran: Joined ISRO in 1969 as a technical assistant at Vikram Sarabhai Space Centre (VSSC), becoming one of the first female chemical engineers recruited by ISRO. She retired as associate project director of the Cryogenic Upper Stage Project.
    • J Geetha: Joined ISRO in 1972 after working at Bhabha Atomic Research Centre. She reminisces about the challenges of data gathering in the pre-internet era and the mentorship she received from stalwarts like Satish Dhawan and Vasant R Gowarikar.
    • Radhika Ramachandran: Joined ISRO in 1984 and served in various roles, including technical liaison officer at ISRO’s New Delhi office and director of the Space Physics Laboratory. She highlights the merit-based culture and the support for open discussions and suggestions.
    • T S Ramadevi: Joined ISRO in 1970 after completing her BTech from CET, Thiruvananthapuram. She was part of the communications unit and contributed to the growth of ISRO’s transmission technologies. She retired as deputy director of management systems.
    • Athula Devi: Joined ISRO in 1987 and retired in January, having been part of the team that developed base software systems for the Gaganyaan launch. She emphasizes ISRO’s growth through failures and the team’s dedication to projects above personal recognition.

     

    PYQ:

    [2017] India has achieved remarkable successes in unmanned space missions including the Chandrayaan and Mars Orbiter Mission, but has not ventured into manned space missions. What are the main obstacles to launching a manned space mission, both in terms of technology and logistics? Examine critically. (10)

  • Lal Crater on Mars

    Why in the News?

    Back2Basics: International Astronomical Union (IAU)

    • The IAU was founded on July 28, 1919, during the Constitutive Assembly held in Brussels, Belgium.
    • Its creation was prompted by the need for international collaboration in astronomy, especially after the devastation caused by World War I.
    • It aims to promote and safeguard astronomy in all its aspects through international cooperation.
    • IAU is now headquartered in Paris, France.

    Major Activities and Initiatives

    • General Assembly: The IAU holds a general assembly every three years in varying parts of the world at which professional astronomers meet to discuss research, new cooperative ventures, and similar matters of professional interest.
    • Astronomical Nomenclature: IAU standardises the nomenclature of celestial bodies, features, and phenomena. It maintains several working groups dedicated to naming conventions for stars, planets, asteroids, and other objects.
    • Research and Collaboration: It promotes international cooperation in astronomical research and supports initiatives such as observational campaigns, data sharing, and joint projects.
    • Education and Outreach: It is actively involved in promoting astronomy education and public outreach efforts worldwide. It supports educational programs, workshops, and resources for students, teachers, and the general public.

    Membership

    1. IAU membership spans 92 countries. Out of those countries, 85 are National Members.
    2. India is represented by the Astronomical Society of India (ASI).
    3. Its members are professional astronomers from all over the world, at the D. level and beyond, who are active in professional research, education, and outreach in astronomy.

    Crater Names and Significance

    • Lal Crater: Named after Prof. Devendra Lal, former director of PRL, this 65 km wide crater is positioned at -20.98° and 209.34°.
    • Mursan Crater: Named after a town in Uttar Pradesh, India, this ~10 km wide crater is situated on the eastern side of the Lal crater’s rim.
    • Hilsa Crater: Named after a town in Bihar, India, this ~10 km wide crater is positioned on the western side of the Lal crater’s rim.

    Scientific Importance of Lal Crater

    • Lava Coverage: The entire Lal crater area, located in the Tharsis volcanic region on Mars, is covered with lava.
    • Evidence of Water: Geophysical evidence, including a 45-meter thick sedimentary deposit, suggests the presence of water in the subsurface of the Lal crater. This finding supports the theory that Mars once had water flowing on its surface.
    • Infilling Process: Mursan and Hilsa craters, positioned on either side of the Lal crater, offer insights into the infilling process of the Lal crater. Their presence indicates that infilling occurred episodically over time.

    India’s 2nd Quest for Mars

    • The ISRO is expected to launch Mangalyaan-2, or Mars Orbiter Mission 2 (MOM 2), in 2025.
    • The mission will last one year and is aimed at studying the Red Planet.
    • The successor to Mangalyaan-1, or Mars Orbiter Mission 1 (MOM 1), Mangalyaan-2 will consist of only one orbiter and will be launched atop a GSLV Mark III rocket from Satish Dhawan Space Centre.

    Other missions to Mars

    • ExoMars rover (2022): European Space Agency’s mission to explore Mars.
    • Tianwen-1 (2021): China’s Mars Mission aims to explore and study the Martian surface.
    • UAE’s Hope Mars Mission (2021): UAE’s first interplanetary mission focused on studying the Martian atmosphere.
    • NASA’s Mars Insight (2018): A lander designed to study the interior of Mars.
    • NASA’s Curiosity (2012) and Perseverance (2020): Rovers exploring the Martian surface.
    • NASA’s Mars Reconnaissance Orbiter (2005), Mars Odyssey (2001), and MAVEN (2013): Orbiters studying Mars from space.
    • Mars 2 and Mars 3 (1971): Soviet Union’s missions to Mars, which included orbiter and lander components.

     

    PYQ:

    [2016] The Mangalyaan launched by ISRO

    1. is also called the Mars Orbiter Mission.
    2. made India the second country to have a spacecraft orbit the Mars after USA
    3. made India the only country to be successful in making its spacecraft orbit Mars in its very first attempt.

    Which of the statements given above is/are correct?

    (a) 1 only
    (b) 2 and 3 only
    (c) 1 and 3 only
    (d) 1, 2 and 3

  • How SpaceX’s Starship can revolutionise space travel and exploration?

    Why in the News?

    • SpaceX’s Starship rocket completed its first fully successful test flight. This test flight brings SpaceX closer to its goal of creating a fully reusable rocket system, a development that could revolutionize space exploration and travel.

    What is Starship?

    • Starship is a two-stage heavy lift-off vehicle designed for crew and cargo transport to Earth orbit, the Moon, Mars, and beyond.
    • It stands nearly 120 meters tall, surpassing the Saturn V rocket.
    • The Super Heavy booster is powered by 33 Raptor engines, generating significant thrust, surpassing existing rocket systems like NASA’s Space Launch System (SLS).
    • Raptor engine fuel uses a mix of liquid oxygen and liquid methane, enabling efficient propulsion for the rocket.

    Cost Reduction and Efficiency with Starship

    • Starship can carry up to 150 tonnes of payload to low-Earth orbit.
    • It can be refuelled in space, thereby promising a significant reduction in the cost of space travel.
    • In-orbit refuelling allows Starship to operate like an aeroplane, reducing downtime between missions and maximizing efficiency.
    • Starship’s fully reusable design minimizes the need for costly hardware replacement, unlike traditional rocket systems.

    Scientific Benefits of Starship

    • Enhanced Payload Capability: Starship’s capacity for heavy payloads enables the launch of larger space telescopes and equipment for lunar and Martian missions.
    • Exploration Potential: Scientists can deploy larger and more sophisticated instruments, such as drilling rigs, to explore the Moon and Mars in unprecedented detail.
    • Sample Return Missions: Starship’s capability to return to Earth facilitates the retrieval of valuable samples from other planets, aiding in scientific research and understanding.

    PYQ:

    [2018] With reference to India’s satellite launch vehicles, consider the following statements:

    1. PSLVs launch satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
    2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
    3. GSLV Mk III is a four-stage launch vehicle with the first and third stages using solid rocket motors, and the second and fourth stages using liquid rocket engines.

    Which of the statements given above is/are correct?

    (a) 1 only
    (b) 2 and 3
    (c) 1 and 2
    (d) 3 only

  • What are Coronal Mass Ejections (CMEs)?

    Why in the News?

    • India’s solar mission Aditya-L1 recently captured images of the Sun and it’s Coronal Mass Ejections (CMEs) during a solar storm in May.
      • The Active region AR13664 on the Sun erupted several X-class and M-class flares, which were associated with Coronal Mass Ejections (CMEs).

    Coronal Mass Ejections (CMEs)

    • CMEs were discovered in 1971 and established their importance in solar-terrestrial relations later in the 1980s.
    • It consists of massive clouds of solar plasma and magnetic field lines.
    • It typically accompanies solar flares and filament eruptions.
    • The frequency of CMEs varies with the 11-year solar cycle, with about one a week observed during solar minimum and an average of two to three CMEs per day observed near solar maximum
    • They travel at thousands of km per hour.
    • They can lead to geomagnetic storms, aurorae, and in extreme cases, damage to electrical power grids.
    • Not all CMEs interact with Earth, but those that do can cause disruptions to satellite communications and power grids.
    • Halo CMEs are Earth-directed CMEs visible as rings in white-light coronagraph observations.

    About Aditya-L1:

    • Aditya-L1 mission is India’s first space mission to observe the Sun.
    • It is ISRO’s 2nd space-based astronomy mission after AstroSat, which was launched in 2015.
    • It was launched on September 2nd 2023 to observe the Sun and the solar corona.
    • The L1 point is a location in space where the gravitational forces of two massive objects, such as the Earth and the Sun, balance each other out, allowing a spacecraft to “hover” in a stable orbit.

    Launch Details: 

    • Polar Satellite Launch Vehicle (PSLV) with 7 payloads (instruments) on board.

    The 7 payloads include: 

      1. Visible Emission Line Coronagraph (VELC): Images of the solar corona in visible light to study its structure and dynamics.
      2. Solar Ultraviolet Imaging Telescope (SUIT): Images the solar chromosphere and transition region in ultraviolet light to understand heating and dynamics.
      3. Solar Low Energy X-ray Spectrometer (SoLEXS): Measures solar X-ray spectrum to study solar flares and coronal mass ejections.
      4. High Energy L1 Orbiting X-ray Spectrometer (HEL1OS): Measures high-energy solar X-rays to understand particle acceleration.
      5. Plasma Analyser Package for Aditya (PAPA): Measures solar wind plasma properties to study its interaction with Earth’s magnetosphere.
      6. Aditya Solar Wind Particle Experiment (ASPEX): Measures energetic particle properties in the solar wind to study their effects on Earth’s atmosphere.
    • Solar Irradiance Monitor (SIM): Measures solar irradiance variations and their impact on Earth’s climate.

    Objectives:

    • Aditya L1 will study the coronal heating, solar wind acceleration, coronal magnetometry, origin and monitoring of near-UV solar radiation and continuously observe the photosphere, chromosphere and corona, solar energetic particles and the magnetic field of the Sun.

    Location:

    • Aditya is placed in L1 Halo orbit which is about 1.5 million km from the Earth. The orbit allows the mission to look at the Sun continuously.
    • L1 refers to Lagrangian/Lagrange Point 1, one of 5 points in the orbital plane of the Earth-Sun system.
    • Lagrange Points are positions in space where the gravitational forces of a two-body system like the Sun and Earth produce enhanced regions of attraction and repulsion.

    PYQ:

    [2017] The terms ‘Event Horizon’, ‘Singularity’, ‘String Theory’ and ‘Standard Model’ are sometimes seen in the news in the context of-

    (a) Observation and understanding of the Universe

    (b) Study of the solar and lunar eclipses

    (c) Placing satellites in the orbit of the Earth

    (d) Origin and evolution of living organisms on the Earth

     

    https://www.thehindu.com/sci-tech/science/isro-releases-images-of-sun-captured-by-aditya-l1-during-may-solar-storm/article68273124.ece

  • Blaze Star: A Celestial Phenomenon in the Making

    Why in the News?

    • NASA predicts the dim star T Coronae Borealis will become visible to the naked eye by September 2024, reaching brightness comparable to Polaris.
      • A dim star known as the “Blaze Star,” officially designated as T Coronae Borealis (T CrB), located 3,000 light-years from our solar system, is set to become visible to the naked eye for the first time since 1946.

    About the Blaze Star

    • The Blaze Star located in the constellation Corona Borealis, also known as the “Northern Crown,” is situated between the constellations of Bootes and Hercules.
    • To locate Corona Borealis, begin by identifying prominent stars in the summer night sky, such as those of the Big Dipper.

    Understanding the Blaze Star Phenomenon

    • The Blaze Star is a rare recurrent nova, a binary star system comprising a cool, red giant star and a smaller, hotter white dwarf star in orbit around each other.
    • Every 80 years, the red giant transfers matter onto the white dwarf, triggering explosive phenomena.
    • Historical observations suggest the Blaze Star is on the brink of another explosion, following similar brightness patterns observed before previous eruptions in 1866 and 1946.
      • Precursor Signs: The star has been steadily brightening since 2015, followed by a visible dimming in March 2023, mirroring past eruption precursors.

    Implications for Observation

    • Peak Visibility: During its brightness peak, the Blaze Star is expected to be visible to the naked eye for several days, extending to just over a week with stargazing binoculars or a small telescope.
    • Astronomical Insights: The impending eruption offers a unique opportunity for astronomers to observe and study this celestial event, providing valuable insights into stellar evolution and dynamics.

    PYQ:

    [2013]  Consider the following phenomena

    1. Size of the sun at dusk

    2. Colure of the sun at dawn

    3. Moon being visible at dawn

    4. Twinkle of stars in the sky

    5. Polestar being visible in the sky

    Which of the above are optical illusions?

    (a) 1, 2 and 3

    (b) 3, 4 and 5

    (c) 1, 2 and 4

    (d) 2, 3 and 5

  • Galaxy JADES-GS-z14-0: Insights from NASA’s James Webb Space Telescope

    Why in the News? 

    The James Webb Space Telescope (JWST), launched by NASA, has unveiled a groundbreaking find It has captured imagery of the universe’s earliest-known galaxy, revealing unexpected brightness and size given its formation during the universe’s infancy.

    James Webb Space Telescope (JWST)

    • JWST is a joint venture between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA) launched in December 2021.
    • It is an orbiting infrared observatory that will complement and extend the discoveries of the Hubble Space Telescope, with longer wavelength coverage and greatly improved sensitivity.
    • Webb was formerly known as the “Next Generation Space Telescope” (NGST) and it was renamed in 2002 after a former NASA administrator, James Webb.
    • It will be a large infrared telescope with an approximately 6.5-meter primary mirror.
    • JWST is positioned at the Earth-Sun L2 Lagrange point, 5 million km away.
    • It consists of a mirror, spanning 6.5 meters in diameter compared to Hubble’s 2.4 meters, as well as its specialized instruments optimized for infrared observations.

    Key Objectives:

    • JWST observes deeper into the universe than Hubble.
    • Observes celestial objects from earlier epochs.
    • Enables the detection of light from the universe’s earliest stars, dating back over 13.5 billion years.

    About JADES-GS-z14-0 Galaxy 

    • Named JADES-GS-z14-0, this galaxy was formed approximately 290 million years after the Big Bang.
    • Spanning about 1,700 light-years across, it consists of a mass equivalent to 500 million stars akin to our Sun.
    • Despite its ancient age, the galaxy is actively generating stars at a rapid pace, producing around 20 new stars annually.

    Scientific Insights:

    • Historical Context: Previously, the earliest-known galaxy was dated to approximately 320 million years post-Big Bang, indicating the significance of this new discovery.
    • Luminosity Theories: While hypotheses suggest various explanations for the galaxy’s luminosity, including supermassive black holes or unusually bright stars, further research is required to validate these theories.

    PYQ:

    [2012] Which of the following is/are cited by the scientists as evidence/evidence for the continued expansion of the universe?

    1. Detection of microwaves in space
    2. Observation of redshift phenomenon in space
    3. Movement of asteroids in space
    4. Occurrence of supernova explosions in space

    Select the correct answer using the codes given below:

    (a) 1 and 2

    (b) 2 only

    (c) 1, 3 and 4

    (d) None of the above can be cited as evidence

  • Agnibaan Sub Orbital Technology Demonstrator (SOrTeD)

    Why in the News?

    Agnikul Cosmos Private Limited, a space start-up from Chennai, made history by launching the world’s first rocket with a single-piece 3D-printed engine, named Agnibaan Sub Orbital Technology Demonstrator (SOrTeD), from Sriharikota.

    About 3D Printed PS4 Engine

    • The PS4 engine, which forms the uppermost stage of the Polar Satellite Launch Vehicle (PSLV), comprises two Earth-storable liquid engines.
    • It uses a bipropellant combination of nitrogen tetroxide as the oxidizer and monomethyl hydrazine as the fuel, both developed by ISRO’s Liquid Propulsion Systems Centre.
    • This same engine is employed in the Reaction Control System (RCS) of the first stage (PS1) of PSLV.
    • ISRO redesigned the PS4 engine for production using 3D printing technology.
    • The technology helped ISRO bring down the number of parts in the engine from 14 to a single piece.
    • ISRO was able to eliminate 19 weld joints and saved 97% of raw material.
    • It also reduced the overall production time by 60%.

    What is Agnibaan SOrTeD (Suborbital Tech Demonstrator)?

    • Agnibaan SOrTeD is a single-stage launch vehicle powered by Agnikul’s patented Agnilet semi-cryogenic engine.
    • In contrast to traditional sounding rockets, Agnibaan SOrTeD’s vertical take-off and precise trajectory enable orchestrated manoeuvres during flight.

    PYQ:

    [2018] With reference to India’s satellite launch vehicles, consider the following statements:

    1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
    2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
    3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines.

    Which of the statements given above is/are correct?

    (a) 1 only
    (b) 2 and 3
    (c) 1 and 2
    (d) 3 only

  • NASA’s PREFIRE Mission to study Earth’s Polar Regions

    Why in the News?

    NASA launched the ” PREFIRE mission”, deploying twin CubeSats to study heat emissions in the Arctic and Antarctic regions, aiming to enhance climate research.

    What are CubeSats?

    • CubeSats are essentially miniature satellites whose basic design is a 10 cm x 10 cm x 10 cm (which makes up for “one unit” or “1U”) cube — just a little bigger than a Rubik’s cube.
    • weight not more than 1.33 kg.

    • These satellites were first developed in 1999 by California Polytechnic State University at San Luis Obispo (Cal Poly) and Stanford University as educational tools. 
    • However, owing to their low cost and less mass in comparison to traditional satellites, they began to be put in orbit for technology demonstrations, scientific research, and commercial purposes.

    About PREFIRE Mission

    • Jointly developed by NASA and the University of Wisconsin-Madison. 
    • It aims to investigate and comprehend the intricate dynamics of heat emissions from Earth’s Polar Regions, specifically focusing on the Arctic and Antarctica.

    Components:

    • CubeSats: PREFIRE employs shoebox-sized CubeSats, each measuring around 6U (6 units), equipped with advanced instrumentation to facilitate data collection.
      • They measure around 90 cm in height and nearly 120 cm in width when the solar panels, which will power the satellite, are deployed.
      • The two satellites will be placed in a near-polar orbit (a type of low Earth orbit) at an altitude of about 525 kilometres.
    • Thermal Infrared Spectrometers (TIRS): Each CubeSat is outfitted with a Thermal Infrared Spectrometer, meticulously engineered to measure far-infrared radiation emitted by the Polar Regions.

    Mission Objectives:

    1. Investigate heat radiated from Earth’s Polar Regions into space and its impact on climate.
    2. Employ thermal infrared spectrometers to measure far-infrared energy emitted by Earth’s surface and atmosphere.
    3. Improve understanding of the greenhouse effect at the poles and its implications for climate change.
    4. Enhance climate and ice models to predict changes in sea level, weather, snow, and ice cover in a warming world.

    Why study heat budget of the Poles?

    • A large amount of the heat radiated from the Arctic and Antarctica is emitted as far-infrared radiation wavelengths of 3 μm to 1,000 μm within the infrared range of electromagnetic radiation.
    • However, there is currently no way to measure this type of energy.
    • As a result, there is a gap in knowledge about the planet’s energy budget.

    Significance of PREFIRE

    • PREFIRE’s observations will enhance predictions of climate and environmental changes, aiding in mitigating the effects of global warming.
    • Data collected will contribute to updating climate models and improving understanding of Earth’s atmospheric dynamics.

    PYQ:

    [2017] What is the purpose of ‘evolved Laser Interferometer Space Antenna (eLISA)’ project?

    (a) To detect neutrinos

    (b) To detect gravitational waves

    (c) To detect the effectiveness of missile defence system

    (d) To study the effect of solar flares on our communication systems

  • What is Zero Debris Charter?

    Why in the News?

    • The Zero Debris Charter was signed by twelve nations and the European Space Agency (ESA) at the ESA/EU Space Council.

    Zero Debris Charter

      • The Zero Debris Charter was unveiled at the ESA Space Summit in Seville, Spain, in November 2023.
      • The Charter was facilitated by ESA’s “Protection of Space Assets” Accelerator and developed through extensive collaboration among various space actors.
    • Objectives:
    • To achieve debris neutrality in space by 2030.
    • Long-term sustainability of human activities in Earth orbit.
    • Members:
      • The signatory countries are Austria, Belgium, Cyprus, Estonia, Germany, Lithuania, Poland, Portugal, Romania, Slovakia, Sweden, and the United Kingdom.
      • The ESA signed as an International Organization.

    Community Support and Leadership

    • Over 100 organizations are expected to sign the Charter in the coming months.
    • This includes national space agencies, satellite manufacturers, space startups, and astronomical societies.

    Space Debris Challenges

    • ESA estimates over one million pieces of space debris larger than 1 cm in Earth orbit.
    • These debris pieces pose significant risks to satellites and astronauts.

    Threats posed by Space Debris

    Space debris also leads to two major risks:

    1. It creates unusable regions of the orbit due to excessive debris, and
    2. Leads to the ‘Kessler syndrome’ – the creation of more debris due to cascading collisions resulting from one collision.

  • Understanding Water Loss on Venus

    Why in the News?

    Over four billion years ago, Venus had enough water to potentially cover its surface with an ocean approximately 3 km deep, but today, it would remain with only 3 cm.

    • A research by US scientists explain the Non-Thermal Dissociative Recombination (DR) responsible for faster loss of water from Venus.

    About Venus

    • Venus is the second planet from the Sun. It is a terrestrial planet and is the closest in mass and size to its orbital neighbour Earth.
    • Venus is notable for having the densest atmosphere of the terrestrial planets, composed mostly of carbon dioxide with a thick, global sulphuric acid cloud cover.
    • At the surface it has a mean temperature of 464 °C (737 K) and a pressure of 92 times that of Earth’s at sea level.
    • These extreme conditions compress carbon dioxide into a supercritical state close to Venus’s surface.
    • Internally, Venus has a core, mantle, and crust. Venus lacks an internal dynamo, and its weak induced magnetosphere is caused by atmospheric interactions with the solar wind.
    • Venus is one of two planets in the Solar System (the other being Mercury), that have no moons.
    • The rotation of Venus has been slowed and turned against its orbital direction (retrograde) by the currents and drag of its atmosphere.
    • It takes 224.7 Earth days for Venus to complete an orbit around the Sun, and a Venusian solar year is just under two Venusian days long.

    Water Loss on Venus:

    • Venus lost its water primarily due to two factors:
        • Evaporation due to Greenhouse Effect: Its dense atmosphere rich in carbon dioxide, creating a strong greenhouse effect and surface temperatures around 450 degrees Celsius, which prevents water from existing in liquid form.
        • Proximity to the Sun: This leads to the disintegration of water molecules into hydrogen and oxygen in the ionosphere under solar heat and ultraviolet radiation.
    • Mechanism of Water Loss:
    1. Thermal Process: Initially, hydrodynamic escape was significant, where solar heating caused the outer atmosphere to expand, allowing hydrogen to escape into space. This process cooled and slowed about 2.5 billion years ago.
    2. Non-Thermal Process: Focus of recent study; involves hydrogen escaping into space, reducing water formation as oxygen atoms lack hydrogen to bond with.

    Key Research Findings: Non-thermal Dissociative Recombination (DR)

    The discrepancy in water loss rates was addressed by identifying a previously overlooked chemical reaction involving the formyl cation (HCO+).

    • HCO+ dissociative recombination (DR) reaction occurs when HCO+ gains an electron and splits into CO and a hydrogen atom, which then escapes into space.
    • This reaction is responsible for losing out water without evaporation.
    • This reaction was modelled to significantly increase the rate of hydrogen escape, potentially doubling the rate at which Venus lost water.
    • The model suggests that water levels on Venus would have been stable from nearly 2 billion years ago due to the ongoing non-thermal HCO+ DR reaction, yet some water remains today.

    Future Research on Venus

    • Existence of HCO+ Ions: Direct evidence of HCO+ ions in Venus’s atmosphere is still missing. Past missions did not focus on this molecule, and its involvement in water loss was not previously considered crucial.
    • Future Missions: The findings underscore the importance of future Venus missions to investigate the presence of HCO+ in the upper atmosphere, similar to the MAVEN mission to Mars.

    PYQ:

    [2011] What is the difference between asteroids and comets?

    1. Asteroids are small rocky planetoids, while comets are made of ice, dust and rocky material.
    2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.
    3. Comets show a perceptible glowing tail, while asteroids do not.

    Which of the statements given above is/ are correct?

    (a) 1 and 2 only

    (b) 1 and 3 only

    (c) 3 only

    (d) 1, 2 and 3