Astronomers discovered 55 Cancri e in 2004. That was five years before NASA’s Kepler planet-hunting spacecraft was launched, and exoplanet science has come a long way in the intervening years. Astronomers discovered the planet with the radial velocity method rather than Kepler’s transit method. 55 Cancri e was the first super-Earth found around a main-sequence star. The 55 Cancri system was also the first star discovered with four, and then five, planets.
The discovery was big news then; over the years, follow-up work has revealed more details, including that 55 Cancri e is extremely close to its star and has a molten surface.
But one question remained unanswered: How did it get there?
Continue reading “This Hellish Planet Orbits its Star Every 18 Hours. How Did it Get There?”