Subject: Space Technology

Why in the News?

Researchers at the Indian Institute of Astrophysics (IIA) have successfully estimated the abundance of Helium in the Sun’s photosphere with precision for the first time.

About Helium in the Sun’s Photosphere:

• Helium is the second most abundant element in the Sun after Hydrogen and plays a key role in understanding solar composition, opacity, and energy transport.
• However, measuring its precise abundance in the Sun’s photosphere has been challenging due to the absence of observable Helium spectral lines in visible light.
• Traditionally, Helium abundance was estimated using indirect methods like extrapolating data from hotter stars, solar wind observations, and seismological studies of the Sun’s interior.
• These methods lacked direct photospheric observations, making the estimates less accurate.
• Accurate measurements of Helium are essential for modelling the Sun’s opacity and energy transport. This also has broader implications for understanding the composition of other stars.

Novel Method Recently Discovered:

• Researchers from the IIA introduced a novel method to directly estimate Helium abundance in the Sun’s photosphere.
• This technique uses spectral features from Magnesium (Mg) and Carbon (C), overcoming the challenge of no direct Helium spectral lines.
• Spectral lines from Mg, C, and hydrogenated molecules (MgH, CH, C2) were used to infer Helium abundance.
• Equivalent Width analyses and spectrum synthesis techniques helped model the behavior of these elements in varying Helium-to-Hydrogen ratios.
• The Helium-to-Hydrogen ratio in the Sun’s photosphere was found to be 0.1, consistent with previous studies. This confirms the validity of the new method.

Why in the News?

NASA’s Hubble Space Telescope recently discovered the Bullseye Galaxy (LEDA 1313424), which contains 9 rings, an unprecedented number.

This finding offers new insights into galaxy evolution and the possibility of the galaxy evolving into a Giant Low Surface Brightness (GLSB) galaxy.

About the Bullseye Galaxy (LEDA 1313424):

• The Bullseye Galaxy is unique for containing 9 rings, an unprecedented number in the study of ringed galaxies.
• Most ringed galaxies typically have 2 or 3 rings, making this discovery significant.
• The rings are believed to have formed after a collision with a blue dwarf galaxy about 50 million years ago, causing ripples in the gas and creating star-forming regions that became the rings.
• While individual stars’ orbits stayed the same, groups of stars gathered, forming distinct rings over time.
• This discovery offers valuable insights into galaxy interactions and the rare formation of multiple rings.

Bullseye Galaxy and Its Possible Evolution into a GLSB Galaxy:

• It shares traits with GLSB galaxies, such as its extended disk and hydrogen content.
• Researchers suggest that the Bullseye Galaxy might evolve into a GLSB galaxy, providing insights into the formation of such galaxies and the distribution of dark matter in the universe.

Why in the News?

NASA scientists have proposed using quantum technology to study gravitational changes on Earth by deploying a quantum gravity gradiometer (QGG) on a satellite in low-Earth orbit.

About Gravity Gradiometer & Quantum Gravity Gradiometer (QGG):

• A gravity gradiometer measures small variations in gravitational force over short distances.
• How It Works: It detects differences in the acceleration of falling objects, indicating the density of materials below the surface, such as hydrocarbon deposits or geological structures.
• Applications:
  • Oil Exploration: Detects underground hydrocarbon deposits by measuring gravitational differences.
  • Geological Studies: Used to explore subterranean features like minerals and fault lines.

• A Quantum Gravity Gradiometer (QGG) uses quantum technology to achieve much higher precision than traditional gravity gradiometers.

• • How It Works: Atoms are cooled to near absolute zero and manipulated with lasers. The phase shifts of these atoms, proportional to gravitational force, detect tiny changes in gravitational acceleration.
  • It can detect changes as small as 10^-15 m/s² over just 1 meter, offering much finer measurements than traditional instruments.
• Specifications: Weighs 125 kg, has a volume like a 250-liter oil drum, and consumes 350 watts of power (comparable to an older Intel CPU).

Applications of QGG in Space:

• Studying Gravitational Variations: Measures small changes in Earth’s gravitational field, aiding climate change studies, such as melting ice caps and shifting water reserves.
• Earth’s Gravitational Field Mapping: Improves understanding of Earth’s internal structure and seismic activities.
• Dark Matter Research: Provides insights into dark matter by detecting gravitational anomalies.
• Satellite Navigation: Enhances space navigation and satellite positioning.
• Mapping Underground Features: Used to map structures like mineral deposits and fault lines.
• Security: Detects underground structures like military bunkers and natural disasters, offering valuable security information.

Why in the News?

The ISRO through its CROP remote sensing framework, has estimated that the total wheat production from eight major wheat-growing states will reach 122.724 million tonnes by March 31, 2025.

About CROP:

• CROP is a semi-automated and scalable framework developed by ISRO’s National Remote Sensing Centre (NRSC).
• The primary goal of CROP is to provide a real-time view of the sowing, growth, and harvest progress of crops, especially wheat during the Rabi season.
• CROP utilizes data from multi-source remote sensing satellites to monitor agricultural areas across India.
• Technological Components of CROP:

1. 1. EOS-04 (RISAT-1A): Provides Synthetic Aperture Radar (SAR) data for crop monitoring, especially under varied weather conditions.
   2. EOS-06 (Oceansat-3): Offers optical remote sensing data for agricultural monitoring.
   3. Resourcesat-2A: Used for high-resolution optical imaging, focusing on agricultural areas for precise crop monitoring.

Key Features of the Study:

• The study used a combination of SAR and optical data to accurately assess crop progress during the 2024-25 Rabi season.
• The wheat sown area, as of March 31, 2025, stands at 330.8 lakh hectares, which is in line with the figures reported by the Ministry of Agriculture and Farmers Welfare (324.38 lakh hectares as of February 4, 2025).
• Wheat production in the eight major wheat-growing states is estimated to be 122.724 million tonnes by March 31, 2025, based on the data gathered through the remote sensing method.

Why in the News?

50 years ago on April 19, 1975, India marked a major milestone in its space history with the successful launch of Aryabhata, its first satellite.

About Aryabhata

• Aryabhata, India’s first satellite, was launched on April 19, 1975, with Soviet assistance from the Kapustin Yar Cosmodrome.
• Named after the ancient Indian mathematician and astronomer Aryabhata, the satellite was a significant milestone in India’s space journey.
• It had a unique 26-sided polyhedron design, measuring 1.4 meters in diameter and weighing 360 kg.
• The satellite’s faces were covered with solar panels, except for the top and bottom.
• Aryabhata orbited the Earth every 96.3 minutes with an inclination of 50.7 degrees, and its apogee and perigee were 619 km and 563 km, respectively.
• Its mission was to conduct experiments in solar physics and X-ray astronomy.
• Despite experiencing a power failure after 5 days, Aryabhata continued transmitting data for several more days, completing a remarkable 17 years in orbit.
• This success was pivotal for India, establishing the country’s space capabilities.

Why in the News?

Kerala State Electricity Board (KSEB) has partnered with IIT Bombay to launch a pilot project on Vehicle-to-Grid (V2G) technology, integrating electric vehicles into the power grid.

About V2G Technology:

• V2G enables Electric Vehicles (EVs) to send power back to the grid when not in use, turning EV batteries into decentralized energy storage devices.
• It involves two key functions:

1. Grid-to-Vehicle (G2V): Power is transferred from the grid to charge the EV.
2. Vehicle-to-Grid (V2G): Power is sent from the EV back to the grid, making the vehicle a distributed energy source.

• Smart charging strategies optimize charging based on grid demand and renewable energy availability, enhancing grid stability and enabling renewable energy integration.

Applications of V2G:

• Grid Support: EVs can supply power back to the grid during high-demand periods, improving grid stability.
• Solar Energy Integration: V2G encourages charging during the day when solar power is abundant, and storing excess energy to supply the grid at night.
• Emergency Power Source: EVs can act as backup power during crises or natural disasters, providing electricity to communities.

Why in the News?

Scientists using the James Webb Space Telescope (JWST) have found signs of possible life on exoplanet K2-18 b by detecting gases usually produced by Earth’s biological processes.

Key findings of the Recent Study:

• Scientists detected significant biosignatures in the atmosphere of K2-18 b, including dimethyl sulphide (DMS) and dimethyl disulfide (DMDS).
• These gases, on Earth, are primarily produced by marine phytoplankton.
• High concentrations of these gases suggest the possibility of microbial life, particularly in the planet’s oceans.
• However, researchers caution that this is not definitive proof of life but a potential biosignature indicating biological processes.
• Further studies and observations are needed to confirm whether these gases are biologically produced or the result of other processes.

About 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 isa 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, and its specialised instruments optimised 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.

Why in the news?

China has unveiled the Three Gorges Antarctic Eye telescope in Antarctica.

About the Three Gorges Antarctic Eye Telescope

• The Three Gorges Antarctic Eye is a 3.2m wide radio/millimetre-wave telescope located at China’s Zhongshan Station in Antarctica.
• It was developed by China Three Gorges University (CTGU) and Shanghai Normal University (SHNU).
• This telescope can detect radio waves and millimeter waves, types of invisible light, allowing scientists to study phenomena like neutral hydrogen and ammonia molecules, essential for understanding star formation and gas movement in space.
• Unlike most telescopes, it works with both radio and millimeter waves, providing a more comprehensive view of space.
• It is built in one of the harshest environments on Earth, with operating temperatures below -60°C and strong winds, making construction particularly challenging.

Why in the News?

The European Space Agency (ESA) is preparing to launch Biomass Mission to map the world’s forests and enhance our understanding of their crucial role in the global carbon cycle.

About the Biomass Mission by ESA

• The ESA will launch the Biomass mission on April 29, 2025, aboard the Vega C rocket from French Guiana.
• The mission aims to map the world’s forests, gathering data on their role in the carbon cycle and how they change over time.
• It will be placed in a sun-synchronous orbit (SSO) at around 666 km, optimizing sunlight for observations.
• It is the 7th mission in ESA’s Earth Explorer Program, focusing on data related to Earth’s atmosphere, hydrosphere, and land surface.

Features of the Biomass Mission:

• Biomass uses a P-band Synthetic Aperture Radar (SAR) sensor (70 cm frequency), capable of penetrating forest canopies to measure carbon storage in trees and the forest floor.
• It will be the first satellite to use this cutting-edge P-band SAR technology, offering unprecedented forest biomass data.
• Equipped with a 12-meter antenna, the satellite will deploy upon launch to conduct broad Earth observations.
• It will create 3D images of forests, from canopy to roots, providing detailed insights into forest health and carbon storage.

Significance of the Biomass Mission:

• The mission will fill critical gaps in forest biomass and height data, improving understanding of forests’ role in the carbon cycle and climate change.
• Biomass will measure carbon storage in forests and track changes due to deforestation and human activity.
• The mission’s data will aid climate change mitigation strategies by tracking carbon fluxes between forests and the atmosphere.
• It will support environmental monitoring, assist policymakers, and contribute to global climate change strategies.