Indian scientists identify a few Martian analogue sites

1. At a Glance

• A University of Kerala team used a laser Raman spectrometer funded under DST-FIST to identify two hydrous sulphate minerals. It found melanterite at Neyveli (Tamil Nadu), and gypsum in the Atacama Desert (Chile) and the Tiruchirappalli Badlands (Tamil Nadu). On that basis the team proposed these places as Martian analogue sites [1].
• Terrestrial analogue sites matter because recent studies show that orbital data alone cannot fully characterise Martian minerals. Measurements on the ground, using precise instruments, are needed as well [1].
• The topic links several UPSC areas: space science and astrobiology, S&T infrastructure schemes (FIST), Indian geology (Neyveli lignite) and India's planetary exploration plans, including ISRO's Ladakh analogue mission [1][4].

2. Why in the News

• 16 Oct 2026: the Ministry of Science & Technology announced the result through a PIB release, "Indian scientists identify a few Martian analogue sites" [1].
• The work appeared as two research papers in the Journal of Geophysical Research: Planets (DOIs 10.1029/2025JE009544 and 10.1029/2026JE009913) [1].

3. Background & Evolution

• The water-on-Mars question: sulphate minerals that contain water are signs of past water on Mars. In 2011, NASA's Opportunity rover found a bright vein, called "Homestake", on the rim of Endeavour Crater. It was probably gypsum (a hydrated calcium sulphate), likely laid down by groundwater [5].

• Before that, orbiters had found a dune field of windblown gypsum on far northern Mars [5].

• FIST (Fund for Improvement of S&T Infrastructure in Universities and Higher Educational Institutions) was launched by DST in 2000–01. It strengthens research infrastructure in university and college departments [2][3].

• The analogue-mission track in India: on 31 Jul 2025 the ISRO Chairman inaugurated HOPE (Himalayan Outpost for Planetary Exploration) in Tso Kar Valley, Ladakh, led by ISRO's Human Space Flight Centre [4].
• Oct 2026: the University of Kerala's DST-FIST facility added mineralogical analogue sites in Tamil Nadu and Chile [1].

4. Core Static Facts

Item	Fact
Ministry	Ministry of Science & Technology, through the Department of Science & Technology (DST) [1]
Institution	Department of Geology, University of Kerala [1]
Team lead	Dr. Sajin Kumar K.S., Project Coordinator, DST-FIST [1]
Instrument	Laser Raman spectrometer, which detects each mineral's distinctive "spectral fingerprint" [1]
Mineral 1	Melanterite, found at Neyveli, TN. It forms from marcasite in the lignite layer beneath the surface, and indicates short-lived wet, acidic, oxidising conditions created by sulphide oxidation [1]
Mineral 2	Gypsum, found in the Atacama Desert (Chile) and the Tiruchirappalli Badlands, TN. It records past water activity and can preserve biosignatures inside the mineral [1]
Shared class	Both are hydrous sulphates that record water–rock interactions [1]
Tiruchirappalli Badlands	A semi-arid terrain of geological and paleoclimatic interest [1]
Journal	JGR: Planets (2 papers) [1]
FIST scheme type	Central Sector Scheme, fully funded and implemented by DST [2][3]
FIST restructuring	Reoriented towards Atmanirbhar Bharat: facilities are opened to start-ups, MSMEs and manufacturers, and must be listed on the I-STEM portal and display the FIST logo [2][3]
ISRO HOPE (Ladakh)	Has an 8 m Habitat Module and a 5 m Utility Module. The site was chosen for high UV flux, low air pressure, cold extremes and saline permafrost, which resemble early Mars [4]
Mars gypsum	Opportunity's Homestake vein, on the Endeavour Crater rim [5]

Standard mineralogy, not taken from the sources (marked †): gypsum = CaSO₄·2H₂O; melanterite = FeSO₄·7H₂O; marcasite = FeS₂, the same chemical formula as pyrite but a different crystal structure.†

5. Multi-Dimensional Analysis

Scientific / Technological

• On Mars, orbital spectroscopy cannot settle mineral identity on its own. Ground-truthing on Earth with Raman spectroscopy makes the interpretation of mission data more reliable [1].
• Melanterite shows how sulphate forms when sulphide minerals oxidise. Gypsum is a mineral that can preserve signs of life. Together they cover both the process and the preservation side of the question [1].
• Minerals that record water and preserve biosignatures can help choose landing and sampling sites for future missions [1].

Governance / Administrative (S&T capacity)

• This is an example of DST-FIST working as intended: a state university department carried out planetary research published in a leading journal [1][2].
• The restructured FIST opens facilities to other users through I-STEM, so expensive instruments can be shared beyond their host institution [2][3].

Strategic / Space programme

• The work complements ISRO's HOPE analogue station in Ladakh. The Ladakh station is a habitat and operations analogue, while the Tamil Nadu sites are mineralogical analogues. India therefore has both kinds [1][4].
• Scientific collaboration with Chile is implied, since one site is in the Atacama Desert [1].

Environmental / Geographical

• The sites are semi-arid and hyper-arid landscapes. Neyveli's lignite mining area also has a reactive sulphide-rich layer below the surface, which the oxidation process depends on. Extreme environments like these are useful as scientific archives [1].

Astrobiology

• The team is now looking for rare analogue sites in extreme conditions worldwide, to study primitive life [1].

6. Recent Developments (last 12–18 months)

• 31 Jul 2025: ISRO inaugurated the HOPE analogue station in Tso Kar Valley, Ladakh [4].
• 2025–26: the two JGR: Planets papers were published (the DOI series show 2025 and 2026) [1].
• 16 Oct 2026: PIB announced the Martian analogue sites in Tamil Nadu and Chile [1].

7. Prelims Hooks

• Melanterite was identified at Neyveli, Tamil Nadu. It forms from marcasite in the lignite layer [1].
• Gypsum was identified in the Atacama Desert (Chile) and the Tiruchirappalli Badlands (TN) [1].
• Both minerals are hydrous sulphates that record water–rock interactions [1].
• Melanterite indicates transient wet, acidic, oxidising conditions [1].
• Gypsum can preserve biosignatures in its mineral matrix [1].
• The instrument used was a laser Raman spectrometer [1].
• The research institution was the Department of Geology, University of Kerala, not ISRO [1].
• The funding was under the DST-FIST programme of the Ministry of Science & Technology [1].
• The findings appeared in Journal of Geophysical Research: Planets [1].
• FIST was launched in 2000–01. It is a Central Sector Scheme fully funded by DST [2][3].
• Restructured FIST requires facilities to be listed on the I-STEM portal [2][3].
• HOPE stands for Himalayan Outpost for Planetary Exploration. It is in Tso Kar Valley, Ladakh and was inaugurated on 31 Jul 2025 [4].
• NASA's Opportunity rover found the gypsum vein "Homestake" on the Endeavour Crater rim [5].

8. Why Testing on Earth Matters: Orbiters Have Missed Sulphates

• Orbiters see some sulphates, but not all of them
• From orbit, scientists did spot a large field of windblown gypsum on far northern Mars [5].
• But a NASA report on Mars Sample Return notes that the sulphates at Jezero crater were not detected from orbit. They became clear only when the rover studied them on the ground [6].

• So a map made from orbit can miss the very minerals that record water. That is why the note's claim that "orbital data alone cannot fully characterise Martian minerals" matters [1].

• Raman spectroscopy is already used on Mars, so Earth samples are directly useful

• NASA's Perseverance rover carries SHERLOC, which combines Raman and fluorescence spectroscopy (two ways of reading a mineral's fingerprint from scattered or glowing light) with a microscope camera [8].
• At a rock called Wildcat Ridge, SHERLOC found organic molecules lying in the same spots as sulphate minerals [7].

• The Kerala team used the same kind of method, a laser Raman spectrometer, on the same mineral family, hydrous sulphates [1]. Their Neyveli and Tiruchirappalli spectra can therefore help scientists read rover data like SHERLOC's.

• For Mains: use this point to show that the Indian work answers a real gap in Mars science. It is not just a local discovery.

9. Where the Earth Sites Stop Matching Mars

• The minerals match, but the surroundings do not
• ISRO picked Ladakh for HOPE because it has high UV radiation, low air pressure, extreme cold and salty permafrost, all of which resemble early Mars [4].
• Neyveli and the Tiruchirappalli Badlands are warm, semi-arid places at normal Earth air pressure [1].

• So these sites are analogues for how the minerals form. They are not analogues for the conditions a mineral faces on Mars after it forms. Do not call them "Mars-like environments" in an answer.

• On Earth, a sign of life in gypsum is expected. On Mars it is not proof

• Gypsum can preserve biosignatures (chemical or physical traces left by living things) inside the mineral [1].
• On Earth, microbes live almost everywhere, so finding such traces in Atacama gypsum is unsurprising.
• On Mars, NASA itself warns that organic molecules found with sulphates "may also have been produced without the presence of life" [7].

• The real value of the analogue sites is to learn how to tell a biological signal from a non-biological one. This builds on the note's trap point that "analogue site ≠ evidence of life".

• Neyveli is a working mine site

• Melanterite there forms from marcasite in the lignite layer [1]. Neyveli is India's main lignite belt, and mining keeps exposing and changing that layer.
• Scientists need to separate what is natural oxidation (a Mars-like process) from what mining has caused. A site disturbed by mining is a weaker analogue than an untouched one.

10. Who Gains First: Foreign Rovers, Not an Indian Lander

• India's only Mars mission so far was an orbiter
• Mangalyaan (Mars Orbiter Mission) launched on 5 Nov 2013 and entered Mars orbit on 24 Sep 2014 [9].

• An orbiter studies Mars from above. Ground-truth data like the Kerala team's is most useful for a lander or rover that touches the surface. India has not yet flown one to Mars.

• So the first users of this work are other countries' missions

• Right now, the mission reading Raman data on Martian sulphates is NASA's Perseverance [7][8].
• The Wildcat Ridge sample can only be fully checked once it returns to Earth through the NASA–ESA Mars Sample Return campaign [7].

• India gets scientific credit and journal papers [1]. The mission advantage, though, depends on India later building its own Mars lander with a Raman-type instrument.

• This is the honest answer to "how does this help India's space programme?"

• It builds skills and reference data in advance. It pays off for missions only when an Indian surface mission exists.

11. What Should Follow: Turning Two Papers Into a National Capability

• DST should make the Kerala Raman facility a shared national resource
• Restructured FIST already requires funded facilities to be listed on the I-STEM portal (a national website where researchers can book instruments at other institutions) [2][3].

• If this spectrometer and its mineral spectra are opened through I-STEM, other universities can test more Indian sites without buying their own instrument.

• Build a public reference library of Indian analogue minerals

• A Raman fingerprint is only useful if there is a known sample to match it against [1].
• SHERLOC on Perseverance identifies sulphates and organics on Mars by reading their spectra this way [7][8].

• A published Indian library of melanterite and gypsum spectra, recorded under controlled conditions, would give any future Indian lander team a ready reference.

• ISRO should link its habitat analogue with these mineral analogues

• HOPE in Ladakh tests how crews and equipment work in Mars-like conditions [4]. The Tamil Nadu sites test how minerals form [1].

• Raman fieldwork on HOPE's salty permafrost would test the instrument in cold, high-UV, low-pressure conditions, which the Tamil Nadu sites cannot provide [4].

• Test the equipment before planning an Indian Mars lander

• NASA flew SHERLOC to Jezero after years of instrument work, and it found organics alongside sulphates [7][8].
• If India plans a surface mission after Mangalyaan [9], it should test a portable Raman instrument at these Indian analogue sites first.

12. Anchors for Answers

• Data: Sulphates at Jezero crater were not detected from orbit. They were confirmed only by the rover on the ground [6].
• Data: Mangalyaan launched on 5 Nov 2013 and reached Mars orbit on 24 Sep 2014. It was an orbiter, not a lander [9].
• Report/Committee: NASA technical report "Thresholds of Temperature and Time for Mars Sample Return: Final Report". It records sulphate detections that orbit missed [6].
• Comparison: NASA Perseverance's SHERLOC Raman instrument found organic molecules in the same spots as sulphates at Wildcat Ridge (Sept 2022). NASA said these may also have formed without life [7][8].
• Scheme: DST-FIST with I-STEM listing lets expensive instruments be shared nationally [2][3]. ISRO HOPE in Ladakh is the habitat analogue that matches Mars conditions [4].

13. Mains Relevance

• GS-III: Science & Technology, specifically awareness in the field of space; achievements of Indians in S&T; indigenisation of technology.
• GS-I (secondary): distribution of key natural resources (Neyveli lignite) and physical geography (badlands, deserts).
• Question stems: 1. What are terrestrial analogue sites? Discuss their significance for India's planetary exploration programme, citing recent Indian examples. 2. Public funding of university research infrastructure can yield frontier science. Examine with reference to the DST-FIST scheme. 3. Discuss the role of mineralogical evidence in the search for past habitability on Mars.

14. Related Topics to Study Next

• ISRO HOPE / Ladakh analogue mission: the habitat-side counterpart to these mineralogical analogues [4].
• Mars Orbiter Mission (Mangalyaan) and a possible future Indian Mars mission: the main use for ground-truth data.
• Raman effect / C.V. Raman: the physics behind the instrument; National Science Day.†
• I-STEM portal and Atmanirbhar Bharat in S&T: linked to the FIST restructuring [2][3].
• Neyveli lignite field: India's main lignite belt; geography of coal resources.
• NASA Mars rovers (Opportunity, Curiosity, Perseverance): earlier sulphate and water discoveries [5].
• Astrobiology and biosignatures: the larger question these sites serve.
• Badlands formation (Chambal, Tiruchirappalli): geomorphology for GS-I.

15. NCERT Concepts to Revise

• Mineral (Geography): The whole study is about identifying minerals (gypsum, melanterite) and what they reveal about past water.
• Oxidation (Geography): Melanterite forms when sulphide minerals like marcasite oxidise, giving wet, acidic, oxidising conditions.
• Lignite (Geography): Melanterite was found in the lignite layer at Neyveli, so knowing lignite explains the site.
• Neyveli lignite (Geography): Neyveli is India's largest lignite deposit and the Indian site where melanterite was identified.
• Atacama Desert (Geography): This hyper-arid Chilean desert is one of the gypsum sites proposed as a Mars analogue.
• Badlands (Geography): The Tiruchirappalli Badlands are a gypsum analogue site; this explains the terrain type.

16. Common Errors / Trap Areas

• Wrong agency: this was University of Kerala + DST-FIST, not ISRO. The ISRO analogue work is the separate HOPE station in Ladakh [1][4].
• Mixing up minerals and sites: melanterite is at Neyveli only. Gypsum is at Atacama and Tiruchirappalli [1].
• Wrong mineral class: these are hydrous sulphates, not carbonates, clays or chlorides [1].
• Wrong meaning: melanterite shows short-lived wet, acidic conditions. Gypsum shows past aqueous activity and preserves biosignatures. Don't swap them [1].
• "Analogue site" ≠ evidence of life: these sites help interpret Mars data. They do not show that life exists on Mars [1].