Martian proton auroras were originally discovered by MAVEN and subsequently found in data from ESA’s Mars Express mission, but most of these previous observations show uniform auroral emission across the dayside of the planet. By contrast, the EMUS observations are able to unambiguously reveal small-scale spatial structures. Scientists from both teams now believe the patchy aurora can only be produced by plasma turbulence in the space surrounding Mars.
The simultaneous observations of patchy proton aurora by Hope and measurements of plasma conditions by MAVEN are therefore a window into rare circumstances, when the interaction between Mars and the solar wind is unusually chaotic.
Hope has observed patchy aurora multiple times over the course of its mission so far, and the shape of the aurora is not always the same. On 2021 August 30, for example, the patchy proton aurora was confined to a much smaller portion of the disk than on August 11, suggesting a different mechanism may be at work. Plasma turbulence at Mars can occur under a variety of conditions, and different shapes of patchy proton aurora may reveal different plasma conditions.
As of June 2022, Mars is about a month away from the peak of its Southern Summer, when proton aurora are known to be at their most active.
