Mars Moons: Facts & Information
- In 1877, astronomer Asaph Hall discovered Phobos and deimos, the two moons of Mars, while peering through his telescope in Washington, D.C.
- Unlike Earth's round moon, Phobos and Deimos are small, irregularly shaped, and dark.
- phobos, the larger of the two, measures about 14 miles across, while Deimos is only about 7 miles.
Unravel the secrets of Phobos and Deimos, the tiny moons of Mars, in this comprehensive report. Discover the ongoing scientific debate: are these Martian moons captured asteroids, or remnants of a colossal collision? This article from News Directory 3 dives into the intriguing origins of these celestial bodies, exploring current research. The upcoming MMX mission,planned for launch in 2026,is poised to collect samples,providing crucial data regarding the composition and history. Learn the potential implications for understanding the early solar system and the possibility of past Martian life. Discover what’s next in the quest to solve this interplanetary puzzle, and analyze the composition to reveal.
The Origins of Mars’ Moons: Phobos and Deimos Explained
Updated June 29, 2025
In 1877, astronomer Asaph Hall discovered Phobos and deimos, the two moons of Mars, while peering through his telescope in Washington, D.C. The moons are named after the Greek mythological figures of terror and panic, fitting companions to the god of war.But these Martian moons are far from typical.
Unlike Earth’s round moon, Phobos and Deimos are small, irregularly shaped, and dark. Christopher S. Edwards, a professor of astronomy and planetary science at Northern Arizona University, described them as “bumpy, potato shaped” with a darkness similar to new asphalt.
phobos, the larger of the two, measures about 14 miles across, while Deimos is only about 7 miles. Their diminutive size and unusual shapes have led scientists to question their origins. are they captured asteroids, or did they form from debris after a large object collided with Mars?
Nancy Chabot, chief scientist for the Space Exploration Sector at the Johns Hopkins Applied Physics laboratory, said the formation of Mars’ moons is “a major open question for science.”
Image credit: NASA/JPL-Caltech/University of Arizona
Evidence supports both theories. Spectral analyses suggest a composition similar to asteroids. Though, Edwards notes that Mars’ relatively weak gravity makes it difficult to explain how the planet could have captured two asteroids into such specific orbits. Data from the Hope Emirates Mars Mission also indicates slightly different compositions between the two moons, further complicating the picture.
The upcoming Martian Moons Exploration (MMX) mission by the Japan Aerospace Exploration Agency (JAXA), scheduled to launch in 2026, aims to shed light on this mystery. The mission will explore Phobos and Deimos and bring a sample from Phobos back to Earth.
“JAXA’s MMX mission is very exciting and is set to be the first to unravel the mysteries of the Martian moons, including answering how they formed,” Chabot said.
Analyzing the composition of the Phobos sample will help determine whether the moons are captured asteroids or formed from Martian debris. If the sample indicates a collision origin, it could even provide insights into whether early Mars was habitable.
Edwards suggests that such a sample “could actually be samples of early Mars,” perhaps revealing clues about the Red Planet’s past habitability.
What’s next
The MMX mission promises to revolutionize our understanding of Mars and its moons. The analysis of the Phobos sample will provide crucial data to finally determine the origin of these enigmatic celestial bodies and potentially unlock secrets about the early solar system and the possibility of past life on Mars.