  Auroras are emissions in a planetary atmosphere caused by its interactions
with the surrounding plasma environment. They have been observed in most
planets and some moons of the solar system. Since their first discovery in
2005, Mars auroras have been studied extensively and is now a rapidly growing
area of research. Since Mars lacks an intrinsic global magnetic field, its
crustal field is distributed throughout the planet and its interactions with
the surrounding plasma environment lead to a number of complex processes
resulting in several types of auroras uncommon on Earth. Martian auroras have
been classified as diffuse, discrete and proton aurora. With new capability of
synoptic observations made possible with the Hope probe, two new types of
auroras have been observed. One of them, which occurs on a much larger spatial
scale, covering much of the disk, is known as discrete sinuous aurora. The
other subcategory is one of proton auroras observed in patches. Further study
of these phenomena will provide insights into the interactions between the
atmosphere, magnetosphere and the surrounding plasma environment of Mars. We
provide a brief review of the work done on the subject in the past 17 years
since their discovery, and report new developments based on observations with
Hope probe.
