Earth is graced by a single, stunning moon that lights up our nights. Meanwhile, Mars, our next door neighbor, is home to two diminutive, irregularly shaped moons named Phobos and Deimos. How did our planetary neighbors end up with such radically different satellites? Let’s explore and compare Mars moons vs Earth moon.
In this article, we’ll cover how these moons stack up against each other. We’ll start by examining some of the basic attributes of each moon, like formation, size, mass, and composition. This will showcase some of the fundamental differences between our moon and moons of our neighboring planets.
By the end, you’ll understand how Earth ended up with the majestic moon we see today compared to the humbler moons captured by Mars’ gravitational pull. The story of how these moons came to be is intertwined with the history of our Solar System itself.
Mars Moons vs Earth Moon – Fundamental Differences
Earth’s moon and Mars’ moons, Phobos and Deimos, exhibit key differences. Earth’s moon is larger, more massive, and made of rock and metal similar to Earth’s crust. Phobos and Deimos are much smaller and consist of carbon-rich rock and dust.
Earth’s moon likely formed from a collision between Earth and another body. This is known as the giant impact hypothesis. However, Phobos and Deimos are believed to be captured asteroids based on their irregular shapes and compositions. They also lack major geological features like those seen on our Earth’s moon.
Martian Moons
Mars has two small, irregularly-shaped natural satellites called Phobos and Deimos. They are significantly smaller than Earth’s moon and orbit very close to the Martian surface. Though diminutive, these moons provide insights into Mars’ formation and orbital history. They also influence its geography through tidal forces.
Mars’ two natural satellites
Phobos and Deimos have similarities, like their irregular, elongated shapes and darker surfaces containing lots of craters. But there are differences, too.
Phobos is larger, with dimensions of about 17 x 14 x 11 miles. It orbits closer to Mars, about 5,827 miles above the surface, completing an orbit in just 7.66 hours. Deimos is smaller at 7.5 x 5.1 x 3.9 miles and orbits further out, about 14,580 miles above Mars, taking 30.35 hours.
Both moons have very low density and are believed to contain lots of porous rock, suggesting the composition of rubble and carbonaceous materials. Observations indicate their surfaces are uniformly dark gray. Grooves and streaks on Phobos may point to past structural failures.
The origin of these moons remains debated, with leading theories of asteroid capture or co-formation with Mars.
Martian Moons vs Earth Moon
Comparing and contrasting the Martian moons with Earth’s moon
Earth’s moon and Mars’ moons, Phobos and Deimos, exhibit stark differences in size, density, form, and composition.
The lunar diameter is over 2700 miles, dwarfing Phobos at 17 miles wide and Deimos at just 8 miles. Earth’s moon has substantial mass, while Phobos and Deimos are lightweight. Lunar composition is rich in minerals like feldspars, while the Martian moons contain lots of carbonaceous chondrite material.
Overall, the irregular, diminutive shapes and makeup of Phobos and Deimos contrast dramatically with the large, spherical, mineral-rich Earth moon.
Surface features and geological characteristics
Surface features of Martian moons
Phobos and Deimos exhibit heavily cratered surfaces, indicating great age. Numerous craters of varying sizes and shallow grooves or valleys cover the moons. These represent major surface features along with random palimpsests and regolith layers.
Impact cratering is the dominant geological process shaping the moons over time. Craters build up as the moons are bombarded by space debris. Grooves likely formed as orbital forces stressed and fractured the crust.
Surface features of Earth’s moon
The lunar surface displays contrasting features like maria, highlands, and numerous impact craters. Maria are ancient solidified lava flows filling large impact basins. Highlands are older crustal regions covered in craters.
Exploration has revealed details of past volcanic activity and lunar history preserved on the surface. Different regions provide a chronicle of major events like asteroid impacts or lunar magma rising to the surface. This evidence helps reconstruct the moon’s complex geological past.
Analyzing orbital paths
Orbital paths of Phobos and Deimos
The two moons of Mars, Phobos and Deimos, have unique orbital paths around the Red Planet. Phobos orbits much closer to Mars than Deimos does.
Specifically, Phobos, as mentioned above, orbits at an average distance of only 5,827 miles from the Martian surface. This gives Phobos an orbital period of just 7.66 hours. The highly elliptical orbit of Phobos brings it within 3,700 miles of the Martian surface at times. This irregular orbit could have implications for future manned missions that attempt to land on Phobos.
In contrast, Deimos orbits over 14,580 miles from Mars, taking 30.35 hours to complete one orbit.
The variable distance from Mars may complicate operations. Deimos has a more circular orbit that stays farther from the planet. This could make it a more appealing target for establishing a permanent base.
Earth’s moon orbit
In comparison to the Martian moons, Earth’s moon has a much more distant orbit from its planet. On average, the moon orbits 238.900 miles from Earth. This means it takes the moon around 27 days to complete one orbit around our planet.
While the moon’s orbit is more stable than Phobos, its distance has still posed challenges for past lunar missions. The Apollo missions took around three days to traverse the distance between Earth and the moon.
Future manned missions to Mars will have to overcome much longer travel times. However, the irregular orbit of Phobos may present unique obstacles that are not factors for accessing Earth’s moon.
Conclusion
In reviewing the orbital paths of Phobos, Deimos, and Earth’s moon, we have seen that the Martian moons present unique challenges and opportunities for exploration compared to our own lunar neighbor.
Their irregular orbits bring them tantalizingly close to the Red Planet, yet also complicate logistics. As humans set their sights on one day colonizing Mars, we hope you have realized the key differences between accessing its moons versus our own.
This article has helped you understand better the comparative orbital mechanics between Mars moons vs Earth moon. Their properties will shape future missions as we push farther into the Solar System.