Astronomers utilizing the NASA/ESA/CSA James Webb Space Telescope have identified a previously uncharted small moon, provisionally named S/2025 U 1. This discovery, made from a series of images taken on February 2, 2025, brings Uranus’s total number of moons to 29.
This Webb/nircam image illustrates S/2025 U1 along with 13 of the other 28 identified moons. Image credits: NASA/ESA/CSA/STSCI/M. El Moutamid, SWRI/M. Hedman, University of Idaho.
Situated in the outer solar system, Uranus is the seventh planet from the Sun.
This cyan ice giant, often referred to as a “lateral planet” due to its extreme axial tilt, has a thick atmosphere composed of hydrogen, helium, and methane.
The 28 moons of Uranus include five major ones: Titania, Oberon, Ambriel, Ariel, and Miranda, discovered between 1787 and 1948.
Known as “The Literary Moons,” the moons of Uranus are named after characters from the works of Shakespeare and Alexander Pope.
Astronomers estimate that Uranus’s larger moons are approximately equal parts water ice and silicate rock.
“As part of Webb’s Guest Observer program, we discovered a previously unknown satellite of the ice giant,” explained Dr. Maryame El Moutamid, a researcher at the Southwest Research Institute.
“This object is the smallest ever detected and was observed during a set of 10 long exposures captured by Webb’s near-infrared camera (NIRCAM).”
https://www.youtube.com/watch?v=pa8joehgtg
The moon, provisionally designated S/2025 U1, resides at the end of Uranus’s inner ring.
Estimated to have a diameter of only 10 km (6 miles), its reflectance (albedo) is presumed to be similar to that of other small Uranian satellites.
It is located approximately 56,250 km (35,000 miles) away from the Earth’s equatorial plane, positioned between the orbits of Ophelia and Bianca.
Ophelia has a diameter of about 43 km (13 miles), while Bianca is elongated, measuring 64 x 46 km (40 x 29 miles).
“While it’s a small moon, its discovery is significant. This is something that even NASA’s Voyager 2 spacecraft missed during its flybys nearly 40 years ago,” Dr. El Moutamid remarked.
S/2025 U1 becomes the 14th member of a complex system of small moons, circling inward among the larger moons, including Miranda, Ariel, Umbriel, Titania, and Oberon.
“Unlike other planets, Uranus possesses a remarkable number of small inner moons. The intricate interactions with its ring system indicate a chaotic history that merges the ring and lunar systems,” Dr. El Moutamid noted.
“Furthermore, this new moon’s small size and unexpected nature may lead to the discovery of even more complexities.”
Source: www.sci.news
