Auroras have been found on

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

but they are very different from the high-altitude auroras found on

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. They are occur in the upper atmosphere of Mars and are diffuse and often localized. Ever since their discovery, it has been an area of active research. Mars lacks a substantial

magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

(see: magnetic field of Mars) due to its small size and faster cooling, instead its crustal magnetic field (parts of the Martian magnetic field trapped in the planets crust) is distributed throughout the planet. Its interaction with the surrounding plasma environment (specifically with

electrons The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

and

protons A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' ( elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an electron (the pro ...

) leads to a number of complex processes. This results in several types of auroras that are uncommon here on

. Auroras found on Mars occur in the upper

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

during the night and are very diffuse. They are mostly found having

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

emissions although some visable emission auroras do occur.

History of Observation

On 11 August 2004, the

European Space Agency The European Space Agency (ESA) is a 23-member International organization, international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 ...

Mars Express ''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA. ''Mars Express'' consisted of two ...

found an

glow coming from "magnetic umbrellas" in the Southern Hemisphere.

does not have a global

which guides

charged particles In physics, a charged particle is a particle with an electric charge. For example, some elementary particles, like the electron or quarks are charged. Some composite particles like protons are charged particles. An ion, such as a molecule or atom ...

entering the

. 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. In late December 2014,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

'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 The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...

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. On 18 March 2015, NASA reported the detection of an

aurora An aurora ( aurorae or auroras), also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly observed in high-latitude regions (around the Arc ...

that is not fully understood and an unexplained dust cloud in the

Martian atmosphere The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.85%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and nob ...

. In September 2017, NASA reported that

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

levels on the Martian surface were temporarily doubled, and were associated with an

25 times brighter than any observed earlier, due to a massive, unexpected

solar storm A solar storm is a disturbance on the Sun, which can emanate outward across the heliosphere, affecting the entire Solar System, including Earth and its magnetosphere, and is the cause of space weather in the short-term with long-term patterns compr ...

in the middle of the month. In March 2022, a possible explanation of the auroras observed on Mars was reported. In 2025, the

Perseverance rover ''Perseverance'' is a car-sized Mars rover designed to explore the Jezero (crater), Jezero crater on Mars as part of NASA's Mars 2020 mission. It was manufactured by the Jet Propulsion Laboratory and launched on July 30, 2020, at 11:50 Coordin ...

had detected a green visable-wavelength aurora on Mars.

References

{{reflist Atmosphere of Mars