  Solar cycle 24 is one of the weakest solar cycles recorded, but surprisingly
the declining phase of it had a slow CME which evolved without any low coronal
signature and is classified as a stealth CME which was responsible for an
intense geomagnetic storm at Earth (Dst = -176 nT). The impact of this space
weather event on the terrestrial ionosphere has been reported. However,the
propagation of this CME beyond 1 au and the impact of this CME on other
planetary environments have not been studied so far. In this paper, we analyse
the data from Sun-Earth L1 point as well as from the Martian orbit (near 1.5
au) to understand the characteristics of the stealth CME as observed beyond 1
au. The observations near Earth are using data from the Solar Dynamics
Observatory (SDO) and the Advanced Composition Explorer (ACE) satellite located
at L1 point whereas those near Mars are from the instruments for plasma and
magnetic field measurements on board Mars Atmosphere and Volatile EvolutioN
(MAVEN) mission. The observations show that the stealth CME has reached 1.5 au
after 7 days of its initial observations at the Sun and caused depletion in the
nightside topside ionosphere of Mars, as observed during the inbound phase
measurements of the Langmuir Probe and Waves (LPW) instrument on board MAVEN.
These observations have implications on the ion escape rates from the Martian
upper atmosphere.
