The discovery of planets orbiting other stars is among the most important and exciting in modern science. It turns out that our galaxy is teeming with these exoplanets — astronomers find them everywhere they look, thousands of them so far, with the certainty of many more to come.
And that has given rise to a new discipline devoted to investigating what exoplanets are like. The first breakthroughs have revealed the size of these planets, how quickly they orbit their parent suns, and whether they sit in the so-called habitable zone where liquid water could exist.
But astronomers want to know more and are planning another generation of powerful telescopes to find out. What will this new imaging technology reveal about our these distant worlds?
Today we get an answer of sorts thanks to the work of Moiya McTier and David Kipping at Columbia University in New York. They have developed a technique for spotting mountains and valleys on exoplanets and show how next-generation telescopes should start to reveal this geography and topography in the near future.
The technique is simple in principle. McTier and Kipping point out that mountains and valleys change the silhouette of a planet as it rotates. When a planet passes in front of its sun, these changes should be observable as small variations in the amount of light the planet blocks as it rotates. Over time, as the mountains rotate in and out of view, these variations should provide a record of the “bumpiness” of the planet’s surface. Read More