MEGANE equipped satellite in space
Our Contribution

Examining the Martian Moons

The Mars-moon Exploration with GAmma rays and NEutrons (MEGANE) spectroscopy instrument will provide vital information on the composition of the Martian moons, Phobos and Deimos.

Visit Instrument Site

About the Instrument

Instrument Type
Gamma-Ray and Neutron

The Martian Moons eXploration (MMX) mission is being developed by the Japan Aerospace Exploration Agency (JAXA). The MMX spacecraft will visit the Martian moon Phobos, land on the surface, collect a surface sample, and then deliver that sample to Earth. On behalf of NASA, APL is leading and building one of the spacecraft’s science instruments: a gamma-ray and neutron spectrometer named MEGANE (pronounced “meh-gah-nay”) that will measure the elemental composition of Phobos. MEGANE’s compositional measurements will provide key information to help determine whether Phobos is a captured asteroid or the result of a larger body hitting Mars.

MEGANE consists of a gamma-ray spectrometer (GRS) and a neutron spectrometer (NS). The GRS uses a high-purity germanium sensor designed and built in partnership with Lawrence Livermore National Laboratory, and is the state-of-the-art technology for achieving high-sensitivity gamma-ray spectral measurements. The NS uses two helium-3 gas proportional sensors to measure neutrons in three broad energy ranges. MEGANE builds on experience from the gamma-ray and neutron spectrometer (GRNS) on NASA’s MESSENGER mission to the planet Mercury and will utilize many aspects of the Psyche GRNS, developed for NASA’s Psyche mission.

Learn more about the different components of MEGANE below. Click the images to view larger versions.

All photos: NASA/JAXA/Johns Hopkins APL/Ed Whitman



Slated to launch in the mid-2020s, MMX is a mission led by JAXA that will explore the two Martian moons, Phobos and Deimos, returning a sample from one of them and solving the mystery of where these small moons came from.

Related News

You Are Here
Terrestrial Planets
Graphic of Terrestrial Planets

See More of APL’s Work Across the Solar System

Explore the Destination Map