A European spacecraft heading to explore NASA’s asteroid crash site made a quick stop at Mars, obtaining rare photographs of the planet’s lesser-known moon, Deimos.
### A Unique View of Deimos
Mars boasts two moons, Phobos and Deimos, yet knowledge about them is limited—especially regarding Deimos, the smaller of the duo. Most of the existing images of Deimos have been captured from the Martian surface by rovers. Because the moon is tidally locked, it consistently presents the same face to Mars, leading scientists to have observed only one side of it.
The Hera mission, managed by the European Space Agency (ESA), delivered a rare glimpse of Deimos’ far side. The spacecraft approached within 625 miles of the moon, acquiring detailed images from orbit.
### A Suspenseful Moment for Mission Control
As Hera navigated around Mars, flight controllers on Earth briefly lost contact with the spacecraft due to signal interference. Although the blackout was anticipated, it was still a tense time for the team.
“I was nearly in tears,” remarked Ian Carnelli, Hera’s mission manager, during a webcast. “I realize this is common for spacecraft operators, but each time we lose communication, I get anxious.” When the signal was reestablished, the scientists burst into excitement upon viewing the first images.
### A Celebrity Among Scientists
Among the team analyzing the images was Brian May, renowned guitarist of Queen and an astrophysicist. As a member of Hera’s scientific team, May focuses on stereoscopic imaging, which aids in transforming raw data into 3D representations.
In a webcast, May analyzed the moon’s surface features, highlighting a depression resembling a “saddle” along with several small craters. “It feels like you’re there, witnessing the entire scene before you,” he stated. “The scientific insights we gather from this are immense, and we’re all like kids.”
### Hera’s Objective: Studying an Asteroid Impact
Launched in October 2024, Hera is expected to arrive at Dimorphos—an asteroid previously impacted by NASA’s DART spacecraft—in 2026. In 2022, NASA deliberately crashed a spacecraft into Dimorphos to evaluate planetary defense methods against possible asteroid threats. Hera’s mission aims to follow up on that test, examining the results of the impact.
### An Essential Flyby
The Mars-Deimos flyby was not a diversion but a vital step to adjust Hera’s path toward its final goal. By passing within 3,100 miles of Mars, the spacecraft utilized the planet’s gravity to fine-tune its trajectory.
Scientists are keen to uncover the origins of Deimos and Phobos. Were they once asteroids ensnared by Mars’ gravitational pull, or are they debris from a significant impact that sent material into orbit? The fresh information from Hera may assist in resolving this enduring enigma.
### Advanced Imaging Technologies
During the flyby, Hera employed three sophisticated instruments to analyze Deimos:
– A black-and-white navigation camera for visible-light imaging
– A hyperspectral imager to evaluate the moon’s mineral makeup
– A thermal infrared imager, supplied by the Japanese space agency JAXA, to examine the texture and density of Deimos’ surface
Thousands of images were gathered, and scientists are currently processing the information. One infrared image depicts Deimos with Mars in the background. The Red Planet appears pale blue due to sunlight bouncing off its surface—an effect that will require adjustment to reveal its true hues.
### Looking Forward
The image also highlights significant Martian features, such as the bright Terra Sabaea area near the equator, the Huygens and Schiaparelli craters, and the colossal Hellas Basin—one of the largest known impact craters in the solar system.
In less than two years, Hera will arrive at Dimorphos to carry out an extensive analysis of the asteroid impact, enhancing our understanding of planetary defense and the exploration of space.