In the quest for planetary exploration, Mars holds a special position in view of the many similarities it has with Earth. This article highlights the significant aspects of the concept design and planning which paved the way for the successful Indian Mars Orbiter Mission (MOM). Lessons learnt from historical failures of Mars missions are summarized. The main driving factors of the MOM design are reliability, optimal utilization of existing launch systems, and minimum energy orbit placement around Mars with an innovative, highly elliptic orbit.

Aurorae are detected from all the magnetized planets in our Solar System, including Earth. They are powered by magnetospheric current systems that lead to the precipitation of energetic electrons into the high-latitude regions of the upper atmosphere.

Four small moons—Styx, Nix, Kerberos and Hydra—follow near-circular, near-equatorial orbits around the central ‘binary planet’ comprising Pluto and its large moon, Charon. New observational details of the system have emerged following the discoveries of Kerberos and Styx. Here we report that Styx, Nix and Hydra are tied together by a three-body resonance, which is reminiscent of the Laplace resonance linking Jupiter’s moons Io, Europa and Ganymede. Perturbations by the other bodies, however, inject chaos into this otherwise stable configuration.

Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment.

We show that terrestrial planets in the habitable zones of M dwarfs older than *1 Gyr could have been in runaway greenhouses for several hundred million years following their formation due to the star’s extended premain sequence phase, provided they form with abundant surface water. Such prolonged runaway greenhouses can lead to planetary evolution divergent from that of Earth.