In the present-day solar system, there are four planets that have rings: Jupiter, Saturn, Uranus, and Neptune. However, a new study has suggested that Mars, popularly known as the Red Planet, also had rings in the ancient past.
Mars' Moon Deimos Holds the Key
Scientists revealed that Deimos, one of Mars' moons, has a slightly altered orbit clearly indicating some unknown factor responsible for its tilt. The researchers who took part in the study revealed that learning more about the unexplored area of Deimos' altered orbit helped them to know more about the presence of rings on Mars in the past.
"The fact that Deimos' orbit is not exactly in-plane with Mars's equator was considered unimportant, and nobody cared to try to explain it. But once we had a big new idea and we looked at it with new eyes, Deimos's orbital tilt revealed its big secret," said Matija Ćuk, a research scientist at the SETI Institute, and the lead author of the study, in a recent statement.
According to the researchers, Deimos is slightly tilted by two degrees to the Martian equator. The researchers determined this after analyzing Phobos, another moon of Mars, which they believe will eventually orbit too low to the planet, and the Red Planet's gravity will tear it apart to form a circle.
"This cyclic Martian moon theory has one crucial element that makes Deimos's tilt possible: a newborn moon would move away from the ring and Mars. Which is in the opposite direction from the inward spiral Phobos is experiencing due to gravitational interactions with Mars. An outward-migrating moon just outside the rings can encounter a so-called orbital resonance, in which Deimos's orbital period is three times that of the other moon," added the statement.
Did Mars Have River Systems?
Recently, several studies suggested that Mars once had a healthy river system. According to the research reports, the conditions on Mars in ancient days were very similar to those on Earth. They also hint at the possibility of alien presence on the Red Planet in the past.
To unravel all these mysteries, NASA is soon launching a robotic mission to Mars. The ultimate aim of the mission is to bring back Martian soil samples to determine whether it had conditions to host life in the past.