Astronomers have found  small moons orbiting Neptune and one circling Uranus, increasing the quantity of recognized moons to 16 and 28, respectively.

Highlights: 

• Astronomers discovered new moons around Neptune and Uranus.
• Counts now stand at 16 for Neptune and 28 for Uranus.
• Uranus' S/2023 U1 is 5 miles wide, while Neptune's include S/2002 N5 and S/2021 N1.

Uranus' new moon, the first determined circling of the ice large in nearly two many years and probably the tiniest of its type, is just 5 miles (8 kilometers) huge and takes 680 days to finish one circle. In contrast, certainly one of Mars' moons, Deimos, is thought to be one of the smallest acknowledged moons in our solar system, measuring eight miles (thirteen kilometers) extensive. 

According to a declaration from the Carnegie Institution for Science (or Carnegie Science), the new moon of the blue-inexperienced planet is now referred to as "S/2023 U1" as it waits to be named after a Shakespeare person.

The brighter of Neptune's two new moons is tentatively dubbed "S/2002 N5." At 14 miles (23 kilometers) broad, this newly found satellite appears to be on a 9-year orbit around Neptune. The fainter moon, now known as "S/2021 N1," is 8.6 miles (14 kilometers) wide and orbits Neptune once every 27 years. Both Neptunian moons will be given permanent names inspired by Greek mythological sea gods and nymphs.

The International Astronomical Union's Minor Planet Center, situated in Massachusetts, reported the discovery of three new moons on Friday (Feb. 23). 

Scott Sheppard, a Carnegie Science staff scientist, made the discovery using observatories in Hawaii and Chile, in collaboration with Marina Brozovic and Bob Jacobson of NASA's Jet Propulsion Laboratory (JPL), David Tholen of the University of Hawaii, Chad Trujillo of Northern Arizona University, and Patryk Sofia Lykawa of Kindai University.

The new moons are "the lowest ever found around both of these ice giant planets with ground-based telescopes," Sheppard said in a statement released Friday. "It took special processing of pictures to reveal such faint objects."

He discovered the new Uranian moon in November of last year, using Chile's Magellan telescopes. A month later, more observations paired with JPL scientists' calculations of a likely orbit for the new moon verified the discovery.

The two new occupants of Neptune's moon system were first observed in September 2021. Following the confirmation of the orbit of the brighter of the two natural satellites, S/2002 N5, "it was traced back to an object that was spotted near Neptune in 2003 but lost before it could be confirmed as orbiting the planet," according to Sheppard.

According to the announcement, determining the orbit of the fainter Neptunian moon "required special observing time under ultra-pristine conditions" using Europe's Very Large Telescope in Chile and the Gemini Observatory in Hawaii.

Sheppard and his colleagues used these telescopes to take a series of five-minute exposures spread out over three or four hours. These brief burst photos were then "layered" so that the three new moons could be seen more clearly.

All three moons have egg-shaped orbits that are strongly inclined to the planes of their respective ice giants. This suggests that they were not born on their host planet, but rather gravitationally captured later on.