In News:

In late September, Earth will temporarily capture a small asteroid known as 2024 PT5. This phenomenon, where an asteroid becomes a "mini-moon," will last for about two months before the asteroid escapes back into space. While Earth has gained mini-moons before, such occurrences are quite rare; most asteroids either miss the planet entirely or burn up upon entering the atmosphere.

What Is a 'Mini-Moon'?

Mini-moons are small asteroids that get temporarily captured by Earth's gravity, orbiting the planet for a limited time. These asteroids are typically small and difficult to detect—only four mini-moons have been identified in Earth's history, and none remain in orbit today. Some objects previously thought to be mini-moons were later determined to be space debris, including rocket stages and satellites.

Details About 2024 PT5

Discovered on August 7 through the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS), 2024 PT5 measures approximately 33 feet in length, making it invisible to the naked eye and standard amateur telescopes. However, it is detectable by professional astronomical equipment.

According to Carlos de la Fuente Marcos, a professor at the Complutense University of Madrid, 2024 PT5 originates from the Arjuna asteroid belt, which consists of space rocks that share similar orbits with Earth. There is also speculation that it could be a fragment resulting from an impact on the moon, as noted by Paul Chodas from NASA's Jet Propulsion Laboratory (JPL).

However, some experts argue that 2024 PT5 may not fully qualify as a mini-moon. For an asteroid to be classified as such, it must complete at least one full orbit around Earth. Instead, 2024 PT5 will follow a horseshoe-shaped path, leading Lance Benner, a principal investigator at JPL, to express skepticism about its classification as a mini-moon.

Significance of the Event

Studying 2024 PT5 will provide valuable insights into asteroids that pass near Earth and their potential for future collisions. Additionally, many asteroids are believed to contain precious minerals and water, which could be harvested for future space missions and resource utilization. Observing this mini-moon will enhance our understanding of these celestial bodies and their behavior in Earth's vicinity.

Why is it in the News?

Recently, China launched its second mission to the far side of the Moon. If successful, it will be the world’s first mission to bring back samples from the part of the Moon that the Earth never gets to see.

What is Chang’e-6 Mission?

• China's Chang'e-6 spacecraft launched recently, on a mission to collect samples from the far side of the Moon.
• The mission aims to grab samples containing material ejected from the lunar mantle and thus provide insight into the history of the Moon, Earth, and Solar System.
• It is a 53-day-long mission. After reaching the Moon’s orbit, the mission’s orbiter will circle the natural satellite while its lander will descend into the 2,500-kilometre-wide South Pole-Aitken basin on the lunar surface.
• The impact that created the basin, among the largest in the history of the solar system, is thought to have dug up material from the lunar mantle.
• If that material can be retrieved, scientists can learn more about the history of the Moon’s insides.
• After collecting samples through scooping and drilling, the lander will launch an ascent vehicle, which will transfer the samples to the orbiter’s service module.
  • This module will then return to the Earth.
• China is the only country to achieve a soft landing on the far side of the Moon.
  • In 2019, its Chang’e-4 mission landed on the region and explored the Moon’s Von Karman crater with the help of a rover.

Why is the Far Side of the Moon Important?

• The Moon’s far side is often referred to as the dark side because it cannot be seen from the Earth, not because it does not catch the Sun’s rays.
  • The Moon is tidally locked with the Earth and therefore, we see only one side of the Moon, also known as the near side.
• The far side has been under the spotlight in recent years as it is very different from the near side.
• It has a thicker crust, more craters and fewer maria, or plains where lava once flowed.
• Examining the samples from the far side can help scientists solve mysteries about the origin and evolution of the Moon — till now, scientists have only been able to analyse samples from the near side.
• The far-side samples can also give answers to the longstanding question: why is it different from the near side?
• Going to the far side, getting samples and doing different kinds of geophysical measurements is really important to figuring out this really long, long-standing mystery.

Why is it in the News?

The Bengaluru-based Indian Institute of Astrophysics (IIA) has filmed the passing of the moon in front of Antares, a bright red star.

What is Antares?

• Antares, also known as Alpha Scorpii, is one of the brightest stars in our night sky.
• Located in the constellation Scorpius, Antares has captivated stargazers and astronomers for centuries with its fiery red hue and impressive size.
• The name Antares is derived from the Greek word meaning “rival to Mars” due to its reddish appearance, similar to the planet Mars.
  • Ancient cultures associated Antares with various mythological figures, including the Greek god Ares and the Egyptian god Osiris.
• It is also one of the largest known stars, with a diameter estimated to be around 700 times that of our Sun.
• Antares is located approximately 550 light-years away from Earth, making it a relatively close neighbour in astronomical terms.
•  It is classified as a red supergiant star, belonging to the spectral type M1.5 Iab-Ib.
• Its surface temperature is about 3,500 Kelvin.
• Antares is a variable star, which means its brightness fluctuates over time.
• Scientists estimate that Antares is approximately 12 million years old.
• As a red supergiant, it is in the later stages of its stellar evolution and is expected to explode as a supernova in the future.
• Antares has a mass estimated to be about 15 times that of our Sun.
• It is primarily composed of hydrogen and helium, with traces of heavier elements.
  • Antares has a companion star in a binary system known as Antares B.
  • The two stars orbit each other, with a separation of several astronomical units.
• The visual apparent magnitude of Antares is around 1.06, making it one of the 20 brightest stars in the night sky.
• Antares emits a significant amount of infrared radiation, making it a prominent object in infrared observations.
• Antares experiences intense stellar winds, which cause it to lose mass at a rate of approximately one Earth mass every hundred thousand years.
• Antares played a crucial role in ancient navigation, particularly in the Southern Hemisphere, serving as a marker for determining the position of celestial objects.

Why is it in the News?

An international team of scientists, including from India, has discovered strong evidence indicating the presence of ozone on Jupiter’s moon Callisto, shedding light on the complex chemical processes taking place on icy celestial bodies in the Solar System.

Study on the Formation of Ozone in Callisto's Icy Environment:

• A recent study examined the chemical evolution of sulfur dioxide (SO2)-rich astrochemical ice found on Callisto's surface when exposed to ultraviolet (UV) radiation.
• The investigation revealed a unique signature indicating the formation of ozone, which could have implications for the potential habitability of the Jovian moon.
• Callisto is Jupiter's second-largest moon and the third-largest moon in our solar system.
• It has a relatively stable surface, which could play a vital role in preserving subsurface oceans or potential habitats beneath its icy crust.
  • The study analyzed UV absorption spectra data from ice samples containing SO2, a primary component of Callisto's surface ice, and observed the generation of ozone under UV irradiation.
• Ozone formation on Callisto could have implications for the moon's astrobiological potential, as ozone can protect the surface from harmful radiation.
• Further research is needed to better understand the implications of this discovery on Callisto's habitability and the potential for future exploration missions.

Callisto's Distinctive Environment:

• Following Saturn, Jupiter boasts the second-highest number of moons in the Solar System, with Callisto ranking among its largest moons and holding the position of the third-largest moon overall, after Ganymede and Titan.
• Comprised predominantly of water ice, rocky elements, sulfur dioxide, and traces of organic compounds, Callisto presents a compelling potential for harboring life beyond Earth within the Solar System.
• The moon's extensively cratered surface bears witness to a lengthy history of impacts from asteroids and comets.

Importance of the Research:

• The identification of ozone on Callisto hints at the existence of oxygen, a crucial component essential for the development of intricate molecules vital for life, including amino acids, thus prompting inquiries into the moon's potential for sustaining life.
• This finding also has implications for other icy moons within our Solar System, offering insights that could broaden our comprehension of habitable environments beyond Earth.

Significance of Ozone:

• Consisting of three oxygen atoms bonded together, the ozone molecule plays a pivotal role in shielding life on Earth.
• Situated in the lower region of the Earth's stratosphere, approximately 15-35 kilometers above the surface, the ozone layer acts as a protective barrier.
• Without this layer, ultraviolet radiation would intensify, posing significant threats to various species and disrupting ecosystems.
• Ultraviolet-B and ultraviolet-C, with wavelengths ranging from 290 to 320 nanometers and 100 to 280 nanometers respectively, can cause DNA damage, and mutations, and elevate the risk of skin cancer and cataracts in humans.
• Furthermore, ultraviolet light can impede plant growth and adversely affect diverse organisms.

Why is it in the News?

Fifty-two years after the last successful Apollo mission, a US-made spacecraft landed on the Moon recently which also marks the arrival of private space companies on the lunar surface.

What is Odysseus Lunar Exploration?

• Odysseus is a spacecraft built by Intuitive Machines, embarked on its journey from Earth aboard a Falcon 9 rocket by SpaceX recently.
  • Intuitive Machines, headquartered in Houston, USA, boasts a decade-long legacy in space exploration endeavours.
• Loaded with six NASA payloads, Odysseus set its course for the Moon.
• Its lander module, Nova-C, achieved the milestone of landing in the Moon's south pole region, following Chandrayaan-3's similar feat last year.
• This marks the third successful moon-landing event in under a year, alongside Chandrayaan-3 and Japan's SLIM (Smart Lander for Investigating Moon).

Mission Objectives:

• The primary aim of the lunar lander is to assess the environmental conditions at the Moon's south pole.
• This assessment holds significant importance as NASA gears up for a crewed mission in September 2026 with Artemis III.
• Before sending astronauts to this area, NASA seeks to gather crucial data, including insights into water presence and accessibility, to inform mission planning.

Funding:

• Under the Commercial Lunar Payload Services (CLPS) program, NASA allocated $118 million to Intuitive Machines for this mission.
• CLPS has engaged at least 14 private companies to ferry NASA payloads to the Moon, fostering a collaborative environment aimed at nurturing the private space industry's capabilities in lunar exploration technology and science.

The Significance of Odysseus:

• Advancing Long-Term Lunar Presence: Odysseus' successful landing heralds a transformative phase in lunar exploration, aiming to establish infrastructure and a technological ecosystem capable of sustaining extended human presence.
• Diverging from Past Lunar Missions: In contrast to the moon landings of the 1960s and 1970s spearheaded by the US and the Soviet Union, Odysseus' mission focuses on leveraging lunar resources for sustained exploration.
  • While historic moon landings were remarkable feats, technological limitations of the time hindered the immediate utilisation of lunar resources such as mining.
• Supporting US Commitment to Moon Exploration via Artemis Program: Odysseus' touchdown aligns with the US commitment to rekindle lunar exploration through the ambitious Artemis program.
  • This endeavour transcends mere lunar landing missions, aiming to establish essential infrastructure and a thriving lunar economy conducive to comprehensive exploration.
• Unlocking Lunar Potential as a Gateway to Deep Space: By laying the groundwork for lunar infrastructure and economic activity, missions like Odysseus pave the way for leveraging the Moon as a springboard for deeper space exploration, offering nations unprecedented opportunities for cosmic discovery.

Why is it in the News?

Recently, the “Moon Sniper” lander developed by Japan’s space agency successfully entered lunar orbit.

About the Smart Lander for Investigating Moon (SLIM) Mission:

• The Smart Lander for Investigating Moon (SLIM) is a spacecraft crafted and launched by the Japan Aerospace Exploration Agency (JAXA) on September 7, 2023, from the Tanegashima spaceport.
• Remarkably lightweight at 590 kg, SLIM embarked on its mission alongside XRISM, a cutting-edge X-ray space telescope, on an H-2A rocket.
• Upon launch, SLIM assumed an elliptical orbit around the moon within a span of approximately three minutes.
• Notably, the apogee (farthest point) of this orbit extends to 4,000 km, while the perigee (closest point) hovers at 600 km above the lunar surface.

Objectives of SLIM on the Lunar Surface:

• Before its lunar descent, SLIM is programmed to release two compact rovers known as Lunar Excursion Vehicle (LEV) 1 and 2.
• Working in tandem with SLIM, LEV-1, and LEV-2 are tasked with conducting a comprehensive study of the lunar surface near the designated landing area.
• Their mission encompasses the collection of temperature and radiation readings, as well as endeavours to investigate the moon's mantle.
• This collaborative effort by SLIM and its rovers aims to enhance our understanding of lunar conditions and contribute valuable insights to lunar exploration.

What is the XRISM Mission:

• The X-Ray Imaging and Spectroscopy Mission (XRISM) is a collaborative effort between the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA), with valuable contributions from the European Space Agency (ESA).
• Mission Objective: XRISM is designed to observe X-rays emanating from deep space, aiming to precisely identify their wavelengths with an unprecedented level of accuracy.
  • The mission employs cutting-edge spectroscopy techniques to measure changes in the brightness of celestial objects across various wavelengths.
• Technological Advancements: Leveraging state-of-the-art spectroscopy, XRISM can detect X-rays within a broad energy spectrum ranging from 400 to 12,000 electron volts.
• To provide a perspective, the energy of visible light typically falls within the 2 to 3 electron volts range.
• This expanded energy range enables astrophysicists to gain novel insights into some of the universe's most dynamic regions, vast structures, and entities characterized by formidable gravitational forces.