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Martian moon Deimos appears dark, framed by the brighter planet Mars behind it, in this visible … [+]
Mars and its lesser-known city-sized moon, Deimos, has been imaged by a spacecraft on its way to study an asteroid.
The European Space Agency’s Hera mission has made history by capturing detailed images of Mars and its smallest moon, Deimos, during a flyby on Wednesday, March 12. The flyby, which gave the spacecraft a critical gravity assist, will propel it toward the Didymos binary asteroid system — which NASA successfully deflected into a new orbit in September 2022 using its DART spacecraft.
Martian moon Deimos seen crossing the face of Mars in this sequence of Asteroid Framing Camera … [+]
The spectacular photos — still images and gifs — mark the first scientific use of its instruments beyond the Earth-Moon system. They were taken from about 620 miles (1,000 kilometers) from the far side of Deimos, as seen from Mars. Like the moon, Deimos is tidally locked to Mars, so it shows only one side of the planet.
Martian moon Deimos shines much brighter than the red planet beneath it in this Thermal Infrared … [+]
Deimos orbits Mars every 30.3 hours at a significantly higher altitude than the other moon of Mars, Phobos. Unlike Phobos, which is gradually spiraling toward Mars, Deimos is slowly drifting away. Discovered in 1877 by astronomer Asaph Hall, Deimos is the smaller of Mars’s two moons. Measuring 7.7 miles (12.4 kilometers) across, dust-covered Deimos is thought to be a leftover of a giant impact on Mars or perhaps a captured asteroid.
Martian moon Deimos seen crossing the face of Mars in this sequence of Thermal Infrared Imager … [+]
The flyby is well-timed. As well as being historic images, Hera’s data will help in planning for the Martian Moon eXploration Mission. Led by the Japanese Aerospace Exploration Agency and due to launch in 2026, MMX will take measurements of both Martian moons. Most excitingly, it will land on Phobos to collect a sample and return it to Earth for analysis.
The red planet appears light blue in this near-infrared Hyperscout H image from ESA’s Hera … [+]
The Hera spacecraft, which launched in October 2023, will reach Didymos in 2026. The mission’s next significant milestone will be a series of precision thruster burns in late 2026, culminating in its arrival in December of that year. Its targets are small — Didymos is 780 meters across, and Dimorphos is just 151 meters — many times smaller than Deimos. NASA’s DART crashed into Dimorphos at about 15,000 miles per hour in an effort to see if it was possible to change the trajectory of an asteroid.
Hera is traveling to Didymos to precisely measure exactly what happened and to answer whether — as suspected — it was a successful practice mission for future planetary defense missions.
“This has been the Hera team’s first exciting experience of exploration, but not our last,” said Ian Carnelli, mission manager for the Hera mission. “In 21 months, the spacecraft will reach our target asteroids and start our crash site investigation of the only object in our solar system to have had its orbit measurably altered by human action.”
Wishing you clear skies and wide eyes.
