In 1994, the European Space Agency's Mars Express found an ultraviolet glow coming from "magnetic umbrellas" in the Southern Hemisphere. Mars does not have a global magnetic field which guides charged particles entering the atmosphere. Mars has multiple umbrella-shaped magnetic fields mainly in the Southern Hemisphere, which are remnants of a global field that decayed billions of years ago.[1]

In late December 2014, NASA's MAVEN spacecraft detected evidence of widespread auroras in Mars' northern hemisphere, from about 20°–30°N latitude. The particles causing the aurora penetrated into the Martian atmosphere, creating auroras below 100 km above the surface, Earth's auroras range from 100 km to 500 km above the surface. Magnetic fields in the solar wind drape over Mars, into the atmosphere, and the charged particles follow the solar wind magnetic field lines into the atmosphere, causing auroras to occur outside the magnetic umbrellas.[2]

On 18 March 2015, NASA reported the detection of an aurora that is not fully understood and an unexplained dust cloud in the Martian atmosphere.[3]

In September 2017, NASA reported that radiation levels on the Martian surface were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, unexpected solar storm in the middle of the month.[4]


In March 2022, a possible explanation of the auroras observed on Mars was reported.[5]

References

  1. ^ "In an ultraviolet glow, auroras on Mars spotted by UAE orbiter". NBC News. Retrieved 2021-12-07.
  2. ^ "Auroras on Mars – NASA Science". science.nasa.gov. Retrieved 12 May 2015. Public Domain This article incorporates text from this source, which is in the public domain.
  3. ^ Brown, Dwayne; Neal-Jones, Nancy; Steigerwald, Bill; Scott, Jim (18 March 2015). "NASA Spacecraft Detects Aurora and Mysterious Dust Cloud around Mars". NASA. Release 15-045. Retrieved 18 March 2015. Public Domain This article incorporates text from this source, which is in the public domain.
  4. ^ Webster, Guy; Neal-Jones, Nancy; Scott, Jim; Schmid, Deb; Cantillo, Laurie; Brown, Dwayne (29 September 2017). "Large Solar Storm Sparks Global Aurora and Doubles Radiation Levels on the Martian Surface". NASA. Public Domain This article incorporates text from this source, which is in the public domain.
  5. ^ Girazian, Z.; et al. (27 March 2022). "Space Physics: Discrete Aurora at Mars: Dependence on Upstream Solar Wind Conditions" (PDF). Journal of Geophysical Research. 127 (4). doi:10.1029/2021JA030238. PMID 35866072. S2CID 246029112.
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