By Eric Ralls Earth.com staff writer
A recent study points to an exciting possibility: that Uranus’s moon Miranda, located in the far reaches of our solar system, may harbor a hidden sea beneath its icy crust, making it hospitable to extraterrestrial life.
Discovering water on the moon is no easy task. It’s even harder when that moon is hundreds of millions of miles away.
Tom Nordheim, a planetary scientist at the Johns Hopkins Applied Physics Laboratory (JHAPL), is the person who gave us a peek into these icy depths.
“To find evidence of an ocean inside a small object like Miranda is incredibly surprising,” said Nordheim, who co-authored the study.
His team’s work challenges our understanding of Miranda while positing new questions about the potential for life on other celestial bodies.
Miranda’s bizarre moonscape
Recall 1986 when Voyager 2, NASA’s intrepid spacecraft, beamed back the first close-up images of Miranda. It was a sight to behold.
A bizarre landscape that looked as if it had been stitched together from bits and pieces of different worlds.
From deep grooves and towering cliffs to mysterious trapezoid-shaped regions known as coronae, Miranda appeared to be a geological wonder. But what could have caused such a varied landscape?
What’s the deal with Uranus?
Uranus is one of the lesser-known planets in our solar system. Unlike the other planets, Uranus rotates on its side, so its axis is almost parallel to its orbit.
This tilt causes some extreme seasons — imagine a planet where each pole gets 42 years of continuous sunlight followed by 42 years of darkness.
Scientists think a massive collision with an Earth-sized object might have knocked it over early in its history.
Another interesting aspect is Uranus’s atmosphere, which is rich in icy materials like water, ammonia, and methane. That methane is what gives the planet its signature blue-green color.
Uranus also has a set of faint rings and at least 27 moons, many named after Shakespearean characters like Miranda, which is the subject of this article, and Ariel.
Despite being discovered way back in 1781 by William Herschel, Uranus still holds many secrets, and researchers are eager to explore it further to understand more about these distant, icy worlds.
Hidden ocean on a moon named Miranda
Caleb Strom, a graduate student at the University of North Dakota, and Alex Patthoff from the Planetary Science Institute in Arizona joined Nordheim for this fascinating study.
They approached this mystery like detectives working a cold case, revisiting old Voyager 2 images and using modern computer modeling techniques to reconstruct Miranda’s geologic past.
As Strom and his team mapped out Miranda’s convoluted surface features and modeled different scenarios for its interior structure, a startling picture began to emerge.
Their findings suggest that around 100 to 500 million years ago, Miranda likely harbored a subsurface ocean, at least 62 miles deep, beneath a frozen crust no more than 19 miles thick.
“That result was a big surprise to the team,” said Strom. The thought that a moon as small as Miranda could contain such a large ocean is not something scientists expected.
Tidal forces on the moon Miranda
Even more confusing is the fact that this ocean could have been warm enough to remain liquid, despite Miranda’s incredible distance from the Sun.
The credit goes to a dance of gravitational forces played out between Miranda and her neighboring moons orbiting Uranus.
This phenomenon, known as orbital resonance, can generate friction and heat within a moon’s interior, enough to sustain a subsurface ocean.
Could Miranda still have a liquid ocean?
The case isn’t closed yet. The team believes that Miranda’s interior hasn’t entirely frozen over. If it had, we would see specific surface features that just aren’t there.
So, there’s a good chance that Miranda still has a subsurface ocean, though likely thinner than before.
“But the suggestion of an ocean inside one of the most distant moons in the solar system is remarkable,” remarked Strom.
This isn’t the first time a small moon has surprised us. Back in 2004, Enceladus, one of Saturn’s moons, revealed active geysers spewing water vapor and ice into space, hinting at a hidden ocean. Today, Enceladus is a prime target in the search for extraterrestrial life.
Could the Miranda moon support life?
It’s still too early to pack our bags for Miranda, but the possibility of it harboring life is tantalizing. However, as Nordheim points out, we still need more data to confirm if an ocean definitely exists.
While recent research has provided fresh insights into Uranus’s moons, we’ve barely scratched the surface.
“We’re squeezing the last bit of science we can from Voyager 2’s images,” says Nordheim.
To truly understand Miranda’s potential, we need to launch new missions to Uranus. Until then, we hold our breath and watch this icy moon with great anticipation.
Miranda, ocean worlds, and extraterrestrial life
In the grand scheme of our solar system, Miranda might just be the underdog story we didn’t see coming.
This tiny moon, once thought to be a frozen, inactive world, could be hiding a vast ocean beneath its patchwork surface.
The idea that such a small body, orbiting one of the most distant planets, might have an environment capable of sustaining life is nothing short of mind-blowing.
All of this goes to show that there’s so much left to discover out there. Revisiting old data with fresh eyes has opened up new possibilities and questions.
Maybe it’s high time we head back to Uranus and take a closer look at Miranda and its neighboring moons.
The full study was published in The Planetary Science Journal.
