We may be able to see mountains and valleys on distant worlds

If alien planets have canyons and mountains like ours, we may be able to catch a glimpse of them in an exoplanet’s shadow as it passes in front of its star

There are stunning mountain ranges on Earth, Mars and even Pluto. But what about worlds further afield?

Moiya McTier at Columbia University in New York presented her research into the embryonic field of exotopography on 11 January at a meeting of the American Astronomical Society. She says that by analysing the dip in a star’s light as a planet passes in front of it, we might be able to discern actual details about the planet’s landscape.

None of the rocky planets in our solar system are perfectly round: there are mountains, canyons, craters and other features that carve elevations high and low across a surface. So why shouldn’t there be similar features on planets orbiting other stars?

McTier took US Geological Survey maps of our four terrestrial planets and the moon to determine what their light curve around