Martian auroras as seen by UAE’s Al-Amal orbiter
Using data gathered by the Al-Amal orbiter (“Hope” in English), scientists have identified three types of aurora on Mars. The image to the right, figure 1 from their paper, shows these types, crustal field aurora, patchy aurora, and sinuous aurora. From the abstract:
We categorize discrete auroral patterns into three types: those near strong vertical crustal magnetic field, patchy aurora near very weak crustal fields, and a new type we call “sinuous,” an elongated serpentine structure that stretches thousands of kilometers into the nightside from near midnight in the northern hemisphere.
All three types generally occur during the Martian night, and evolve quickly over periods of less than 45 minutes. The first type, which is generally the brightest, forms over terrain where Mars’ residual magnetic field is strongest and vertically oriented, and was most often seen over the southern cratered highlands centered between the large impact basins Argyre and Hellas. The third type, sinuous aurora, was more unusual:
These we are calling “sinuous discrete aurora,” due to their thin, elongated, and sometimes serpentine shapes. They share several key traits: (a) they appear in the northern hemisphere away from strong crustal fields, (b) they usually connect to the dayside in the far north but also sometimes separately at lower latitudes, (c) they extend for thousands of kilometers into the night side, (d) they appear on both dusk and dawn sides, and (e) their shapes change moderately and brightnesses shift by factors of up to two over timescales of ∼20 min (i.e., the time between swaths, as shown in the differences between Figures 1j and 1k [in the figure above).
The existence of aurora on Mars has been known since the 2000s. These observations however are the first that show more details beyond a fuzzy patch.
Using data gathered by the Al-Amal orbiter (“Hope” in English), scientists have identified three types of aurora on Mars. The image to the right, figure 1 from their paper, shows these types, crustal field aurora, patchy aurora, and sinuous aurora. From the abstract:
We categorize discrete auroral patterns into three types: those near strong vertical crustal magnetic field, patchy aurora near very weak crustal fields, and a new type we call “sinuous,” an elongated serpentine structure that stretches thousands of kilometers into the nightside from near midnight in the northern hemisphere.
All three types generally occur during the Martian night, and evolve quickly over periods of less than 45 minutes. The first type, which is generally the brightest, forms over terrain where Mars’ residual magnetic field is strongest and vertically oriented, and was most often seen over the southern cratered highlands centered between the large impact basins Argyre and Hellas. The third type, sinuous aurora, was more unusual:
These we are calling “sinuous discrete aurora,” due to their thin, elongated, and sometimes serpentine shapes. They share several key traits: (a) they appear in the northern hemisphere away from strong crustal fields, (b) they usually connect to the dayside in the far north but also sometimes separately at lower latitudes, (c) they extend for thousands of kilometers into the night side, (d) they appear on both dusk and dawn sides, and (e) their shapes change moderately and brightnesses shift by factors of up to two over timescales of ∼20 min (i.e., the time between swaths, as shown in the differences between Figures 1j and 1k [in the figure above).
The existence of aurora on Mars has been known since the 2000s. These observations however are the first that show more details beyond a fuzzy patch.