{
  "annotation_id": "f884354a-3825-43f4-afcf-4c82756691f4",
  "date_created": "2026-03-02T18:01:04.336000Z",
  "date_modified": "2026-03-02T18:01:04.336000Z",
  "file_hash": "d76a7993fb24ee68af95bb83030041381f3bffd8bdee4a803d2c85db0aede035",
  "private": false,
  "record": {
    "abstract": "The recent discovery of liquid water-related sulphates on Mars is of great\nastrobiological interest. UV radiation experiments, using natural Ca and Fe\nsulphates (gypsum, jarosite), coming from two selected areas of SE Spain\n(Jaroso Hydrothermal System and the Sorbas evaporitic basin), were performed\nusing a Xe Lamp with an integrated output from 220 nm to 500 nm of 1.2 Wm-2.\nThe results obtained demonstrate a large difference in the UV protection\ncapabilities of both minerals and also confirm that the mineralogical\ncomposition of the Martian regolith is a crucial shielding factor. Whereas\ngypsum showed a much higher transmission percentage, jarosite samples, with a\nthickness of only 500 microns, prevented transmission. This result is extremely\nimportant for the search for life on Mars as: a) jarosite typically occurs on\nEarth as alteration crusts and patinas, and b) a very thin crust of jarosite on\nthe surface of Mars would be sufficient to shield microorganisms from UV\nradiation.",
    "arxiv_id": "physics/0512140",
    "authors": [
      "Gabriel Amaral",
      "Jesus Martinez-Frias",
      "Luis Vazquez"
    ],
    "categories": [
      "physics.ins-det"
    ],
    "title": "Astrobiological significance of minerals on Mars surface environment:   UV-shielding properties of Fe (jarosite) vs. Ca (gypsum) sulphates",
    "url": "https://arxiv.org/abs/physics/0512140"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "edc9e644-3476-4d09-9d56-60375c6e7e62",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}