It was a rarest of the rare coincidence. A close flyby of a comet near Mars with three orbiters in close vicinity. The tree orbiters were Mars Odyssey, Mars Reconnaissance Orbiter and Mars Atmosphere and Volatile Evolution (MAVEN) orbiter.
It however also put the orbiters in a dangerous situation but still allowed a rare opportunity to study the comet at close range. The giant comet named A1 Siding Spring, buzzed past Mars in the close proximity of NASA’s three orbiters.