SPACE SCIENCE CONSOLIDATED NOTES (CURRENT DEVELOPMENTS)

ASTEROIDS & PLANETARY DEFENCE

Vera Rubin Observatory Discovery (Chile)

• Vera Rubin Observatory discovered 2,000 unknown asteroids within 10 hours
• Highlights the growing capability of wide-field sky surveys and rapid detection systems
• Strengthens planetary defence mechanisms by identifying previously unseen objects

Skyscraper-size “Twilight” Asteroid – 2025 SC79

• 2025 SC79 identified as a massive asteroid hidden in the Sun’s glare
• Categorised as a “twilight asteroid” (observed near sunrise/sunset conditions)
• Emphasises difficulty in detecting objects located close to the Sun’s line of sight

Asteroid 2024 YR4 – Possible Lunar Impact

• Potential collision with the Moon in December 2032
• Could produce a bright flash visible from Earth
• No threat to Earth but important for impact modelling and planetary defence studies

Earth’s Mini-Moon – 2025 PN7 (Arjuna Asteroid)

• Classified as a quasi-moon / quasi-satellite, not a permanent natural satellite
• Re-observed on 29 August 2025 by Pan-STARRS Observatory
• Represents a class of Near-Earth Objects (NEOs) temporarily associated with Earth

MOONS & PLANETARY SYSTEMS

New Moon Around Uranus (JWST Discovery)

• Discovered by James Webb Space Telescope (JWST)
• Temporary designation: S/2025 U1
• Size: ~10 km diameter (extremely small)
• Orbital distance: ~56,000 km from Uranus’ centre
• Located between moons Ophelia and Bianca
• Total known moons of Uranus increased to 29
• Demonstrates capability of infrared astronomy in detecting faint celestial bodies

Discovery of 128 New Moons Around Saturn

• 128 new moons discovered, total rises to 274 moons
• Saturn becomes the planet with the highest number of satellites
• Discovery method: “Shift and Stack Technique”
• Indicates presence of numerous small irregular moons

EXOPLANETS & EXTREME PLANETARY CONDITIONS

TOI-561 b – Ultra-hot Super-Earth

• Ultra-short period exoplanet (orbital period < 11 hours)
• Studied using JWST’s NIRSpec (Near-Infrared Spectrograph)
• Measurement based on near-infrared brightness of dayside temperature
• Likely structure: global magma ocean
• Described as a “wet lava ball”

L 98-59 d – Molten Planet with Unique Chemistry

• Characterised by global magma ocean
• Rock exists in a “mushy state” (neither fully solid nor liquid)
• Rich in sulphur, leading to emission of hydrogen sulphide gas
• Associated with “rotten egg smell”
• May possess a thick hydrogen-dominated atmosphere

BD+05 4868 Ab – Disintegrating Exoplanet

• Small rocky exoplanet undergoing continuous disintegration
• Cause: extreme stellar heat
• Produces a comet-like tail of material
• Size range: between Mercury and Earth’s Moon
• Represents a rare cosmic phenomenon

EXOPLANETARY ATMOSPHERES & BIOSIGNATURES

K2-18b – Revised Biosignature Debate

• Earlier hypothesis: Presence of Dimethyl Sulfide (DMS)
  • On Earth, DMS is linked to biological activity (marine algae)
• New findings revise earlier claims → biosignature not confirmed
• Confirmed atmospheric gases:
  • Methane (CH₄)
  • Carbon dioxide (CO₂)
• Highlights difficulty in identifying definitive signs of extraterrestrial life

INTERSTELLAR OBJECTS & COMETS

Third Interstellar Object – 3I/ATLAS

• Discovered on 1 July 2025 (Chile telescope)
• Initially designated A11pl3Z, later named 3I/ATLAS
• Travels at extremely high velocity
• Follows a hyperbolic orbit → not gravitationally bound to the Sun
• Only the third confirmed interstellar object

Comet C/2024 G3 (ATLAS) – “Great Comet of 2025”

• Achieved exceptional status due to:
  • Extraordinary brightness
  • Daylight visibility
  • Prominent and structured tail
• Recognised as the “Great Comet of 2025”
• Notable for dynamic evolution and rare visibility conditions

STELLAR NEIGHBOURHOOD (NEAREST STARS)

Closest Stars to the Sun

• Alpha Centauri system → 4.34 light-years (closest star system)
• Barnard’s Star → red dwarf in Ophiuchus
• Luhman 16 → nearby brown dwarf system
• WISE 0855-0714 → isolated (“lonely”) brown dwarf
• Wolf 359 → red dwarf at 7.9 light-years, extremely dim
• Lalande 21185 → red dwarf discovered in 1801

THEMATIC SUMMARY TABLE