
Voyager 2’s flew by the Uranian moon Miranda in 1986 and the spacecraft spent 17 minutes taking photos to make this high-resolution portrait. Miranda has three oval and trapezoid coronae, tectonic features whose origins remain debated. (NASA / JPL / Ted Stryk)
When it come to habitable environments in our solar system, there’s Earth, perhaps Mars billions of years ago and then a slew of ice-covered moons that are likely to have global oceans under their crusts. Many of you are familiar with Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) — which have either been explored by NASA or will be in the years ahead.
But there quite a few others icy moons that scientists find intriguing and just possibly habitable. There is Ganymede, the largest moon of Jupiter and larger than Mercury but only 40 percent as dense, strongly suggesting a vast supply of water inside rather than rock.
There’s Saturn’s moon Titan, which is known for its methane lakes and seas on the surface but which has a subterranean ocean as well. There is Callisto, the second largest moon of Jupiter and an subsurface-ocean candidates and even Pluto and Ceres, now called dwarf planets that show signs of having interior oceans.
And of increasing interest are several of the icy moons of Uranus, particularly Ariel and Miranda. Each has features consistent with a subsurface ocean and even geological activity. Although Uranus is a distant planet, well past Jupiter and Saturn and would take more than a decade to just get there, the possibility of a future Uranus mission is becoming increasingly real.
The National Academy of Sciences (NAS) Decadal Survey for planetary science rated a Uranus mission as the highest priority in the field, and just today (Aug. 18) NASA embraced the concept.
At a NASA Planetary Science Division town hall meeting, Director Lori Glaze said the agency was “very excited” about the Uranus mission recommendation from the National Academy and that she hoped and expected some studies could be funded and begun in fiscal 2024.
If a Uranus mission is fully embraced, it would be the first ever specifically to an ice giant system — exploring the planet and its moons. This heightened interest reflects the fact that many in the exoplanet field now hold that ice giant systems are the most common in the galaxy and that icy moons may well be common as well.… Read more