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Moon, Sun and planetary missions

Missions to the Moon, the Sun, the planets and the asteroids, India's and other countries': what each is sent to find, and what it finds. Prelims has asked about Mangalyaan, the Mars Orbiter Mission.

UPSC has asked

Prelims 2016: Mangalyaan, the Mars Orbiter Mission

All 3 subjects shown; the 1 that changed from 16 to 31 July 2026 are marked.Show only these

The lunar south pole

Prelims and Mains

Every serious lunar plan now points at the same few hundred kilometres of the Moon's south, China's as much as America's. Sunlight and water ice do not usually sit near one another, and there they almost do.

Sunlight lasts longer near the lunar poles, which a solar powered outpost needs.
A permanently shadowed region is a crater floor beside them that the Sun never reaches, and the water ice held there is the resource that makes a base worth building.

Why launches wait

China called off Chang'e 7 and postponed its lunar south pole mission to next year, which is less a failure than a fact of orbital mechanics. A launch window missed is a month lost, and for a polar landing often more.

A launch window is when Earth, the Moon and the spacecraft align so the target orbit costs least fuel.
For the Moon a window opens roughly once a month.
A south pole mission needs a near polar orbit, which the 5.1 degree tilt of the Moon's orbit complicates.
A solar powered lander must also land in sunlight.

What changed

Space weather forecasting from Aditya-L1

Prelims and Mains

A solar flare gives no useful warning once it has erupted, because its radiation crosses to Earth in about eight minutes. Space weather forecasting is the attempt to read the Sun's atmosphere for a sign hours before that, and India's first solar mission has now found one.

Aditya-L1 watches the Sun from a halo orbit around L1, the first Sun-Earth Lagrange point, about 1.5 million kilometres from Earth.
From L1 the Sun can be watched without the Earth ever coming in the way.
A study using Aditya-L1 found that a major solar flare is preceded, hours ahead, by small short-lived brightenings clustered where it later erupts.
Repeated small releases of magnetic energy appear to destabilise an active region until a large flare breaks out.
The brightenings show in the Sun's lower atmosphere, in SUIT images read together with both X-ray payloads.
Hours of notice would let operators safeguard satellites, astronauts and communication systems.

Solar Ultraviolet Imaging Telescope (SUIT)

Images the Sun in near-ultraviolet light
Gave the pictures of the lower atmosphere where the brightenings appear

Solar Low Energy X-ray Spectrometer (SoLEXS)

Gave the low energy X-ray data

High Energy L1 Orbiting X-ray Spectrometer (HEL1OS)

Gave the high energy X-ray data

The three Aditya-L1 payloads the flare study combined, from The Hindu, 31 August 2026

What changed

31 Aug 2026
The Hindu, 31 Aug 2026: New study captures Sun's early warning signs before solar flares (opens in a new tab)

Science results from Chandrayaan-3 and Aditya-L1

Prelims

Chandrayaan-3 landed near the lunar south pole in 2023 with a thermal probe, a spectrometer, a plasma probe and a seismometer, and Aditya-L1 observes the Sun from the first Lagrange point; this subject holds the scientific results published from both.

What changed

23 Jul 2026New subject
- The ChaSTE thermal probe on Chandrayaan-3 went 10 cm into the surface and gave the first temperature profile measured in place at a high lunar latitude. A sharp change in thermal conductivity at about 6 cm marks a two layer regolith whose porous top acts as a blanket over any water ice below.
- The Pragyan rover's X-ray spectrometer found a uniform, magnesium rich composition that supports the lunar magma ocean hypothesis. The RAMBHA-LP probe made the first plasma measurements near the surface at high latitude, and the ILSA seismometer logged more than 250 vibration events.
- Aditya-L1 captured the first spectroscopic signatures of the onset of a coronal mass ejection.
- The landing and navigation methods proved here feed Chandrayaan-4 sample return, the LuPEX mission with Japan and the Venus Orbiter Mission.
PIB, 23 Jul 2026: PARLIAMENT QUESTION: ACHIEVEMENTS OF ADITYA-L1 MISSION (opens in a new tab)

Also filed elsewhere

The Artemis Accords · on Space policy, private sector and governance
The Artemis Accords are the terms on which the American lunar programme admits a partner, and India accepted them in 2023.