SUNSET: 
Has a Stray Piece of the Moon Become a Quasi-satellite of Earth?
A quasi-satellite of Earth, named Kamoʻoalewa, might actually be a chip off our Moon.
Hail-like “Mushballs” May Fall on All Our Giant Planets
"Mushballs," first inferred to exist on Jupiter, may fall within the atmospheres of all the solar system's giant planets.
Amateur Astronomer Discovers New Moon of Jupiter
An amateur astronomer has discovered a new moon of Jupiter. While it hasn't received official designation yet, it would bring the tally of Jovian satellites to 80.
Giant Oort Cloud Comet Lights Up in the Outer Solar System
Astronomers have discovered a new comet coming from the Oort Cloud — and it appears to be a big one.
Interstellar and Solar System Comets Share a Surprising Ingredient: Nickel
Cold comets — both natives and the interstellar Comet Borisov — have nickel and iron vapor in their atmospheres, and scientists want to know why.
Helium Rain Inside Saturn Might Shape Its Magnetic Field
A thick inner layer of slowly falling helium blobs might help explain Saturn's almost perfectly aligned magnetic field.
Jupiter's Great Red Spot Gets Smaller — But Stronger
"Flakes" coming off the Great Red Spot have had some wondering if this epic storm is coming to an end. But observations and computer modeling show it's only getting stronger.
Can We Expect Seven Interstellar Visitors Per Year?
A new study estimates the number of interstellar objects that fly through the inner solar system every year, and it could be quite a lot.
Second Earth Trojan Asteroid Discovered
A recently discovered asteroid appears to be an Earth Trojan, orbiting a gravitationally stable area with only one other known occupant.
Amateur Astronomer Finds “Lost” Moons of Jupiter
An amateur astronomer has recovered four of five "lost" Jovian moons.
Water on the Moon Isn't Just at the Poles
Water exists even on the sunlit Moon, a new study shows — trapped in glass beads but still extractable for lunar exploration.
Osiris-REX Finds Some of Solar System's Oldest Rocks on Bennu
NASA's Osiris-REX mission has found evidence of ancient water flows on the surface of asteroid Bennu.
The Origin of Earth’s Water
Scientists have discovered a new candidate source for Earth's water: building blocks of the primordial solar system known as enstatite chondrites.
Was Early Mars "Wet and Warm"? Or Wet and Cold?
A new model suggests that Martian valley networks might have been created by ancient subglacial rivers rather than water flowing on the surface.
Jupiter Has Trapped a Comet in a Bizarre Orbit
Jupiter has captured an icy comet from the outer solar system. The comet's bizarre orbit will bring it back for another super-close pass in 2063.
The Origins of Interstellar Objects
The first two interstellar visitors to the solar system are finally shedding light on their places of origin.
Is the Interstellar Comet 2I/Borisov Breaking Up?
New observations of the interstellar comet — which traveled unaltered for eons before arriving in the solar system — have revealed it's fragmenting