ESTEEM Center for Equity in Science, Technology, Engineering, English & Math



Mars Will Soon Have Rings

Mars used to have rings then it had moons and may have rings again
Source: Kevin Gill
Rendering showing a planetary ring system over Mars. Demonstrates either the formation or destruction of Phobos and/or Deimos (CC BY 2.0)

We all know what Mars looks barren red and has two tiny moons. However, it may have had rings in the past & may have rings in the future. Unfortunately, we won’t be around to see it.

How do rings form?

Take Saturn, a planet known for its beautiful rings and thousands of moons. How did Saturn get its rings? Every planet has something called the “Roche limit” – basically a distance where the planet has a stronger gravitational force over a moon’s own gravity which essentially rips the moon apart, forming a ring around the planet. Theories say Saturn may have ripped apart hundreds of icy moons or comets that flew nearby, which may have formed its rings. We can tell because Saturn’s rings are mainly made of ice, which also explains why they’re so bright.

Phobos, one of the two moons of Mars, also the biggest of the two, is currently spiraling into Mars at around 1.6 meters over 100 years. Sounds slow, but in astronomical times, it’s fast. In around 30-50 Million years from now, it will have crossed the aforementioned “Roche Limit” and get ripped apart by Mars’ gravity, forming a ring system around Mars.


The Ring’s Vestige

Rings don’t last forever, we can already see it happening to Saturn due to something called “Ring Rain”. Mars will experience something similar, over millions of years ring debris will crash into Mars fading it away, or it could form a new moon though clumping, like when Theia crashed into Earth which formed rings then later formed The Moon. This “new moon” could spiral into Mars again, get ripped apart, form more rings, & form another new moon which then spiral into Mars Again, repeating the cycle.


The History of Mars.

Mars is kept company by two cratered moons — an inner moon named Phobos and an outer moon named Deimos. (Source: NASA/JPL-Caltech)

This may have explained why Mars’ other moon, Deimos, has a 2° angle in its orbit relative to Mars’ equator. Deimos could have formed millions of years ago along with a “Phobos ancestor”, This “Phobos ancestor” spiraled into Mars while Deimos survived, subjugated to being pushed around by another “Phobos ancestor” that formed, it could of been tens of times bigger than modern-day Phobos. This “Phobos ancestor” orbited 3x closer than Deimos combined with its big mass caused interference with Deimos causing the 2° tilt & then spiraled into Mars’ “Roche Limit” destroying it, forming rings, then forming another “Phobos ancestor” which then spirals into Mars until it forms Phobos today.


Very soon we can confirm this theory, JAXA (Japan’s Space Agency) plans to send a probe to Phobos as part of their Martian Moons Exploration (MMX) mission, this probe will collect data & samples on Phobos & send it back to Earth for scientist to study hopefully revealing the past of Mars & its moons.


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