A Mercury rover could explore the planet by sticking to the Terminator
A view of Mercury's Terminator region, as seen by NASA's MESSENGER probe. Credit: NASA/JPL-Caltech
Below is an excerpt of a story by Matthew Williams published in Universe Today featuring research by Mari Murillo, a planetary science PhD student at in the Hawai’i Institute of Geophysics and Planetology (HIGP), and HIGP researcher Paul G. Lucey.
The closest planet to our Sun, Mercury, experiences extreme temperature variations. Since the planet has no atmosphere to speak of, it is in a constant cycle of where one side is extremely hot and the other extremely cold. On the Sun-facing side, temperatures reach a scorching 427 °C (800 °F), enough to melt tin and lead, and the surface is exposed to extremely lethal levels of radiation. On the night side, temperatures plunge to a chilling −173 °C (-279.4 °F), cold enough to freeze most liquids, including those used in battery manufacturing.
All of this makes exploring Mercury’s surface very challenging. On the one hand, a rover would be subject to interference from the Sun’s radiation on the Sun-facing side and would likely melt down. On the other hand, a solar-powered rover cannot operate on the night side, and a battery-powered vehicle would likely lose power quickly as its batteries die. But in the Terminator, the region between night and day on Mercury, temperatures are stable enough, and there is sufficient light for a solar-powered rover to study surface features and conduct science operations.
This is the proposal put forth by a research team from the Hawai’i Institute of Geophysics and Planetology (HIGP) at the University of Hawai’i at Mānoa. The team included Mari Murillo, a Planetary Science PhD Student at HIGP, and Paul G. Lucey, a prominent researcher with HIGP and Murillo’s PhD advisor. The paper detailing their proposal was presented at the 2026 Lunar and Planetary Science Conference (2026 LPSC).
As they note in their paper, a Mercury lander mission would create opportunities to study unique geological features. These studies would address the unanswered questions scientists have regarding Mercury’s formation, volcanic history, and tectonic evolution. The idea of staying ahead of the Sun on Mercury has been explored extensively by scientists and through science fiction.
For more, read the full story on Universe Today.