Video: Reflections on Clyde Tombaugh

New measurements of the mass of Saturn's rings reveal their age — and something they have in common with dinosaurs.

Data from NASA's New Horizons spacecraft, which explored Kuiper Belt object Ultima Thule earlier this week, is yielding scientific discoveries daily.

Images of the Kuiper Belt object Ultima Thule unveil the very first stages of solar system's history.

NASA's New Horizons spacecraft flew past Ultima Thule in the early hours of New Year's Day, ushering in the era of exploration from the enigmatic Kuiper Belt.

A message from Thomas Zurbuchen, the associate administrator of NASA's Science Missions Directorate, to Alan Stern, New Horizons principal investigator of the Southwest Research Institute in Boulder, Colorado.

On December 31, NASA's OSIRIS-REx spacecraft entered into orbit around the asteroid Bennu, and made Bennu the smallest object ever to be orbited by a spacecraft.