Three New Moons Discovered in the Solar System: Uranus and Neptune Gain New Residents
The solar system has just welcomed three new residents, as astronomers have confirmed the existence of three tiny moons. One of these moons orbits Uranus, while the other two circle Neptune. Although these moons were initially spotted several years ago, their official confirmation came recently from the International Astronomical Union’s (IAU) Minor Planet Center, which is responsible for naming new objects in the solar system.
The newly discovered moons have been given numerical designations for now, but they will eventually be bestowed with formal names inspired by literature and mythology. The process of naming these moons will take place in the coming years.
Uranus’ new moon, S/2023 U1, is incredibly small, measuring only about 5 miles (8 kilometers) across. This makes it one of the smallest known moons among the eight planets in our solar system, comparable in size to Mars’ moon Deimos. It takes approximately 680 days for S/2023 U1 to complete an orbit around Uranus. With the addition of this tiny moon, Uranus now boasts a total of 28 moons. Like its fellow Uranian moons, S/2023 U1 will eventually be named after a character from the plays of William Shakespeare, joining the ranks of previously discovered moons such as Titania, Oberon, and Puck.
Neptune’s new satellites, S/2002 N5 and S/2021 N1, are slightly larger than their Uranian counterpart. S/2002 N5 has a diameter of about 14.3 miles (23 km), while S/2021 N1 measures approximately 8.7 miles (14 km) wide. The orbital period of S/2021 N1 around Neptune is around 9 years, while S/2002 N5 takes nearly 27 years to complete an orbit around the farthest planet from the sun. With the addition of these two moons, Neptune’s moon count now stands at 16. Similar to other moons of Neptune, these newly recognized bodies will be named after the Nereids, who are the daughters of the sea god Nereus in Greek mythology.
Discovering these moons was no easy task, considering their small size and distance from Earth. Ground-based telescopes were used to spot each of these moons. Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington D.C. who was involved in all three discoveries, explained, “The three newly discovered moons are the faintest ever found around these two ice giant planets using ground-based telescopes. It took special image processing to reveal such faint objects.”
Due to their diminutive size and distance from Earth, the movements of these moons are typically too small to be noticeable in most ground-based images of Uranus or Neptune. To overcome this challenge, astronomers employed a technique called image stacking. They took long exposure images and combined them to create images where background objects, such as stars and galaxies, appeared blurred. This stacking technique allowed the relative motions of the moons to stand out more clearly against the background noise.
These recent discoveries are not isolated incidents. In February 2023, the IAU confirmed the existence of 12 new moons around Jupiter, bringing its total moon count to 92, the highest among all planets at that time. However, in May of the previous year, the IAU confirmed a staggering 62 moons around Saturn, surpassing Jupiter’s count and bringing Saturn’s total to 145. Most of these newly discovered moons, which are generally only a few miles across, were also detected using Earth-based telescopes.
These findings highlight how advancements in techniques like image stacking and the use of more powerful ground-based telescopes are enabling researchers to delve deeper into our cosmic neighborhood with greater clarity. As technology continues to improve, we can expect more exciting discoveries and a deeper understanding of the wonders that lie beyond our planet.
