The Mystery of Demos Surface Formation: How an Ancient Impact Changed the Martian Moon?

The small moon "Deimos" is one of the mysterious celestial bodies orbiting Mars, where its smooth surface has long puzzled scientists and space specialists. A recent scientific study published in "Nature Astronomy" reveals a new hypothesis explaining why this moon looks different from its larger counterpart "Phobos," by reimagining the events that shaped its ancient geological history.

Computer Simulations Reveal the Secret of Formation

The research team led by Dr. Sabina Raducan from the International Space Science Institute relied on advanced simulation programs to understand the mechanics of cosmic collisions with high precision. The researchers used a computer program known as "Bern Smoothed Particle Hydrodynamics," a tool developed at the University of Bern in Switzerland over two decades to simulate collisions between different celestial bodies.

This advanced scientific software allows researchers to analyze billions of individual particles involved in each collision scenario, helping to understand the impact of complex physical variables such as density, gravity, and the material strength of rocky bodies. The scientific group conducted about one hundred different simulation processes, each taking a full week, varying the angle, speed, and size of the asteroids in each of their precise experiments.

Scientists compared the results of these complex computer simulations with high-resolution photographs taken by the European space probe "Hera" during its close pass by the moon "Deimos." The comparison showed that the most likely scenario involves an asteroid up to 320 meters wide colliding with the moon at an angle of 45 degrees, an event believed to have radically changed the moon's face.

This massive collision released huge amounts of debris and rocks across the irregular surface of "Deimos," leading to a thick cover of dust and rocky debris known as "regolith." Thanks to this thick layer, which reaches up to 200 meters in some areas, the moon's surface appears much smoother and less cratered than the surface of "Phobos," which is characterized by numerous craters and ancient scars.

Impact on Future Missions

This scientific study provides precise predictions that can be tested in the field through the Japanese Space Exploration Agency's "Martian Moons eXploration" (MMX) mission, scheduled to launch at the end of the current year. This ambitious mission aims to collect samples from the surface of the moon "Phobos" and return them to Earth, as well as provide unprecedented detailed observations of both Martian moons.

Dr. Sabina Raducan states that their results give the Japanese mission a clearer picture of what its instruments can expect during the sample collection and field studies process. Thus, understanding the underlying structure of the dust layer on "Deimos" enhances scientists' ability to extract precise information about the origin and evolution of Mars's moons, contributing to filling a large knowledge gap in the history of the solar system.

The moon "Deimos" is named after terror in ancient Greek mythology, and it is a small rock potato-shaped in form, orbiting at a distance of approximately 24,000 kilometers from the surface of the Red Planet. Its surface contains a huge southern polar crater 10 kilometers wide, which is now a key piece of evidence for the violent collision that reshaped its features billions of years ago.