Wikipedia

Mars ocean theory

theory that nearly a third of the surface of Mars was covered by an ocean of liquid water early in the planet’s geologic history

The Mars ocean theory states that nearly a third of the surface of Mars was covered by an ocean of liquid water early in the planet's geologic history.[2][3] This ocean is called Paleo-Ocean[1] or Oceanus Borealis (/oʊˈsiːənəs ˌbɒriˈælɪs/ oh-SEE-ə-nəs BORR-ee-AL-iss). [4] It would have filled the basin Vastitas Borealis in the northern hemisphere. This region lies 4–5 km (2.5–3 miles) below the mean planetary elevation. It would have existed approximately 4.1–3.8 billion years ago. Evidence for this ocean includes geographic features resembling ancient shorelines, and the chemical properties of the Martian soil and atmosphere.[5][6][7] Early Mars would have required a denser atmosphere and warmer climate to allow liquid water to remain at the surface.[8][9][10]

An artist's impression of ancient Mars and its oceans based on geological data
The blue region of low topography in the Martian northern hemisphere. People though that this was the site of a primordial ocean of liquid water.[1]

Other explanations

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Not all scientists agree that this ocean really existed. The Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) has discovered large boulders on the site of the ancient seabed, which should contain only fine sediment.[11] The boulders could have been dropped by icebergs, a process common on Earth.[12][13] The interpretations of some features as ancient shorelines has been challenged.[14][15][16]

A study published in September 2021 compared potassium isotopes found in rocks from various bodies. The study suggests that the surface gravity on Mars was too low to keep enough water to form a large ocean.

There are other explanations of how the surface gullies and channels were created include wind erosion,[17] liquid carbon dioxide, and liquid methanol.[18]

Confirmation or refutation of the Mars ocean hypothesis awaits additional observational evidence from future Mars missions.

See also

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References

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  1. ↑ 1.0 1.1 Brandenburg, John E. (1987). The Paleo-Ocean of Mars. Lunar and Planetary Institute. pp. 20–22. Bibcode:1987meca.symp...20B.
  2. ↑ Clifford, S. M.; Parker, T. J. (2001). "The Evolution of the Martian Hydrosphere: Implications for the Fate of a Primordial Ocean and the Current State of the Northern Plains". Icarus. 154 (1): 40–79. Bibcode:2001Icar..154...40C. doi:10.1006/icar.2001.6671.
  3. ↑ Rodriguez, J. Alexis P.; Kargel, Jeffrey S.; Baker, Victor R.; Gulick, Virginia C.; et al. (8 September 2015). "Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?". Scientific Reports. 5 (1): 13404. Bibcode:2015NatSR...513404R. doi:10.1038/srep13404. PMC 4562069. PMID 26346067.
  4. ↑ Baker, V. R.; Strom, R. G.; Gulick, V. C.; Kargel, J. S.; Komatsu, G.; Kale, V. S. (1991). "Ancient oceans, ice sheets and the hydrological cycle on Mars". Nature. 352 (6336): 589–594. Bibcode:1991Natur.352..589B. doi:10.1038/352589a0.
  5. ↑ "Mars: The planet that lost an ocean's worth of water".
  6. ↑ "NASA finds evidence of a vast ancient ocean on Mars". MSN.
  7. ↑ Villanueva, G.; Mumma, M.; Novak, R.; Käufl, H.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. (2015). "Strong water isotopic anomalies in the martian atmosphere: Probing current and ancient reservoirs". Science. 348 (6231): 218–21. Bibcode:2015Sci...348..218V. doi:10.1126/science.aaa3630. PMID 25745065.
  8. ↑ Fairén, A. G. (2010). "A cold and wet Mars Mars". Icarus. 208 (1): 165–175. Bibcode:2010Icar..208..165F. doi:10.1016/j.icarus.2010.01.006.
  9. ↑ Fairén, A. G.; et al. (2009). "Stability against freezing of aqueous solutions on early Mars". Nature. 459 (7245): 401–404. Bibcode:2009Natur.459..401F. doi:10.1038/nature07978. PMID 19458717.
  10. ↑ Fairén, A. G.; et al. (2011). "Cold glacial oceans would have inhibited phyllosilicate sedimentation on early Mars". Nature Geoscience. 4 (10): 667–670. Bibcode:2011NatGe...4..667F. doi:10.1038/ngeo1243.
  11. ↑ Kerr, Richard A (2007). "Is Mars Looking Drier and Drier for Longer and Longer?". Science. 317 (5845): 1673. doi:10.1126/science.317.5845.1673. PMID 17885108.
  12. ↑ Fairén, A. G.; Davila, A. F.; Lim, D.; McKay, C. (2010). Icebergs on Early Mars (PDF). Retrieved 2010-10-02.
  13. ↑ Chol, Charles Q. (2010-10-01). "New Evidence Suggests Icebergs in Frigid Oceans on Ancient Mars". www.space.com, Space.Com website. Retrieved 2010-10-02.
  14. ↑ Carr, M. H.; Head, J.W. (2002). "Oceans on Mars: An assessment of the observational evidence and possible fate". Journal of Geophysical Research. 108 (E5): 5042. Bibcode:2003JGRE..108.5042C. doi:10.1029/2002je001963.
  15. ↑ Sholes, S.F.; Montgomery, D.R.; Catling, D.C. (2019). "Quantitative High-Resolution Re-Examination of a Hypothesized Ocean Shoreline in Cydonia Mensae on Mars". Journal of Geophysical Research: Planets. 124 (2): 316–336. Bibcode:2019JGRE..124..316S. doi:10.1029/2018JE005837.
  16. ↑ Malin, M.C.; Edgett, K.S. (1999). "Oceans or seas in the Martian northern lowlands: High resolution imaging tests of proposed coastlines". Geophysical Research Letters. 26 (19): 3049–3052. Bibcode:1999GeoRL..26.3049M. doi:10.1029/1999GL002342.
  17. ↑ Leovy, C.B. (1999). "Wind and climate on Mars". Science. 284 (5422): 1891a. doi:10.1126/science.284.5422.1891a.
  18. ↑ Tang, Y.; Chen, Q.; Huang, Y. (2006). "Early Mars may have had a methanol ocean". Icarus. 180 (1): 88–92. Bibcode:2006Icar..180...88T. doi:10.1016/j.icarus.2005.09.013.
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