Scientists have discovered a strange warm spot deep in the interior of the Red Planet.

The satellites that orbit the Moon and Mars have provided scientists with a wealth of information about the surfaces of those other worlds. They have found traces of water on the Moon and spied potentially habitable surface environments on Mars.

For all that success, using those tools to understand what’s happening beneath the surface, however, has been a taller order. But a technique called tidal tomography, developed by Brown University researchers, is enabling scientists to use existing satellites to glean key information from deep within planetary interiors.

In a study in the journal Nature, a team led by Alexander Byrne from the University of Arizona used the technique to show that Mars has a massive heat anomaly in the mantle beneath its southern hemisphere.

The study suggests that the hot spot is 200 to 400 degrees Celsius warmer than the rest of the planet, a finding that sheds new light on how the Red Planet has evolved over time.

Two Brown researchers who coauthored the study have played key roles in the development and application of tidal tomography. Harriet Lau, an associate professor in the earth, environmental, and planetary sciences department at Brown, previously used tidal tomography to reveal new insights about Earth’s interior. Working with Nick Wagner, a postdoctoral researcher at Brown, they’ve adapted it for Mars, and they hope it will soon reveal new details about the Moon as well.

Here, Wagner digs into the work in an interview: