A picnic on a far-flung planet orbiting a red dwarf might involve spreading your blanket on black grass and munching on purple veggies, according to a new model.

Given that we have yet to find bacteria, let alone little green men or purple palms, on any other planet, it might seem slightly ridiculous to spend time working out what colour plants elsewhere in the Universe must be. But scientists say that the thought experiment could be useful in helping us to look for lush landscapes in other solar systems.

Nancy Kiang, a biometeorologist at the NASA Goddard Institute for Space Studies in New York, modelled the solar and atmospheric conditions of other planets to see which ones might be suitable for photosynthetic life, and what those photosynthesizers might look like.