Neptune and Uranus: Discovery of New Moons

IThree previously unknown moons have been found on the outskirts of the solar system. One orbits Uranus and the other two orbits Neptune. It was discovered in observational data from telescopes in Chile and Hawaii by the team of American astronomer Scott Sheppard of the Carnegie Institution, which specializes in distant moons, and the results were announced last week. Sheppard is largely responsible for the discovery of most of the 95 known moons of Jupiter and 146 moons of Saturn.

Uranus' new moon is only about eight kilometers across and requires more than two Earth years to orbit the second exoplanet in the solar system. This brings the number of known Uranus moons to 28. It was first observed on November 4 last year and was given the temporary name S/2023 U1. However, it will one day bear the name of a character from William Shakespeare's works, as has become common for the outer moons of Uranus.

The brighter of Neptune's two new moons is about 23 kilometers across, and orbits its planet once every nine Earth years, even taking its companion nearly 27 years to do so. It is the faintest moon ever detected by a ground-based telescope, being only about 14 kilometers across, and its planet, the farthest of the large planets in the solar system, is about six times the distance from the sun than Jupiter.

This means that the planet Neptune – named after the Roman version of the Greek sea god Poseidon – now has 17 known satellites. Like the others, the two new additions will eventually be named after sea characters from ancient mythology.