When is the next rover heading to Mars?
Mars 2020
Mars 2020 is a Mars rover mission by NASA's Mars Exploration Program with a planned launch in July or August 2020. It will investigate an astrobiologically relevant ancient environment on Mars, investigate its surface geological processes and history, including the assessment of its past habitability, the possibility of past life on Mars, and the potential for preservation of biosignatures within accessible geological materials. It will cache sample containers along its route for a potential future Mars sample-return mission.
2016 in spaceflight
The ExoMars mission, a collaboration between the European and Russian space agencies, was launched on 14 March and reached Mars on 19 October. Dedicated to astrobiology investigations, this flight carried the ExoMars Trace Gas Orbiter, which reached Mars orbit, and the Schiaparelli EDM lander, which crashed upon landing. A subsequent flight scheduled for 2020 will carry the ExoMars rover along with four static surface instruments. 
Meanwhile, the Japanese space probe Akatsuki started its observations of Venus in May after spending five months gradually adjusting its orbit. 
Planetary exploration activities took center stage with the orbit insertion of NASA's Juno probe at Jupiter on 4 July, followed by the launch of NASA's OSIRIS-REx mission to asteroid 101955 Bennu on 8 September. Finally, on 30 September, the Rosetta probe executed a slow crash-landing on comet 67P/Churyumov–Gerasimenko.