Launched by the European Space Agency (ESA) on June 2, 2003, Mars Express was Europe’s first independent mission to another planet. Its name, “Express,” refers not only to the speed of its journey—taking just six months to reach Mars—but also to the relatively short time from concept to launch, made possible by reusing design elements from ESA’s Rosetta and Mars 96 missions.
It gave Europe a seat at the table of planetary exploration. It taught us that Mars is not a dry, static rock but a dynamic planet with hidden lakes, shifting ice, and a complex climatic history. The mission serves as a bridge between the first generation of Mars flybys (Mariner) and the modern era of sample return.
The Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) is a visible and infrared mapping spectrometer that identifies minerals on the surface. It was crucial in discovering vast deposits of clay minerals and hydrated sulfates—chemical evidence that water once flowed freely on Mars. The Planetary Fourier Spectrometer (PFS) studies the atmosphere’s composition, temperature, and dust content, tracking the global dust storms that occasionally engulf the entire planet. Mars Express
The Mars Express Odyssey: Two Decades of European Deep Space Exploration
Perhaps the most significant contribution of Mars Express has been the confirmation and mapping of water ice. Using its instrument, the probe peered beneath the planet's dusty surface. In 2018, MARSIS data revealed the presence of a 20-kilometer-wide lake of liquid water beneath the southern polar ice cap. This was a monumental discovery, suggesting that liquid water—which is essential for life as we know it—could exist on Mars today, protected from the harsh surface conditions by layers of ice. Launched by the European Space Agency (ESA) on
The High-Resolution Stereo Camera (HRSC) is arguably the mission’s most famous instrument. Unlike traditional cameras, the HRSC captures images in color and stereo simultaneously. This has allowed scientists to create digital terrain models of Mars with unprecedented accuracy. The HRSC has mapped nearly the entire surface of Mars at a resolution of 10 to 30 meters per pixel, with select areas photographed at an astonishing 2-meter resolution. It has revealed ancient river valleys, massive volcanoes like Olympus Mons, deep canyons like Valles Marineris, and seasonal polar ice caps in stunning 3D.
If you are looking for an interesting feature from the Mars Express mission, the discovery of stable bodies of liquid water It taught us that Mars is not a
, the orbiter detected a 20 km-wide zone that reflects radar signals in a way that matches liquid water or water-rich sediments.