# Martian meteorite Teghaza 001 formed at least 4.1 billion years ago, sampling ancient crust

- Published: 2026-11-05 01:23 UTC
- Section: Sky & Space › Astronomy
- Tags: Martian meteorite, Teghaza 001, ancient Martian crust, Mars mantle, igneous rock, oxygen isotopes, aqueous alteration, Mars geology
- URL: https://realtech.media/news/rt-5cace5fe649545cce6b6e28a_martian_meteorite_teghaza/

**Teg 001 is a slowly cooled igneous rock whose composition, mineralogy and texture differ from other Martian meteorites. It shows signs of reactions with fluids.**

![Martian meteorite Teghaza 001 formed at least 4.1 billion years ago, sampling ancient crust](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/2408238bb03fc7fc.jpg)
*Le Scienze*

Researchers described the Martian meteorite Teghaza 001 (Teg 001), a slowly cooled igneous rock that formed at least 4.1 billion years ago, in a paper in Science. [1] Most known Martian meteorites are geologically young and do not represent the planet's surface, which is dominated by ancient rocks. [1]

Its composition, mineralogy and texture differ from other Martian meteorites. According to the authors, Teg 001 is a sample of ancient crust that formed from a geochemically distinct mantle source with primordial composition. [1]

The rock contains aqueously altered minerals. Bulk and mineral-specific oxygen isotope measurements indicate that it reacted with fluids enriched in 18O before an impact ejected it into space. [1]

## Sources

1. [Science](https://doi.org/10.1126/science.adz5646)
2. [Le Scienze](https://www.lescienze.it/spazio-e-astronomia/2026/11/02/news/teghaza_001_la_roccia_marziana_piu_antica_mai_trovata_aggiunge_tasselli_al_passato_umido_del_pianeta_rosso-23046410)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-5cace5fe649545cce6b6e28a_martian_meteorite_teghaza/