International Astronomical Union

An actual image of the protoplanet Hygiea, taken using the SPHERE camera on the Very Large Telescope. Credit: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)

New observations show the asteroid Hygiea is round!

By Phil Plait 2 years ago

Defining which rotation pole is north and which is south on a planet isn't as obvious as you think.

How do you know which pole of a planet is the north pole?

By Phil Plait 2 years ago

Orbits of twelve new moons found for Jupiter (not to scale). Some orbit the same way Jupiter spins (blue), and others the opposite way (red). Credit: Carnegie Institution for Science / Roberto Molar Candanosa

Contest: Pick names for Jupiter's new moons!

By Phil Plait 2 years ago

Pluto and Charon, to scale in size and brightness. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto's posse

By Phil Plait 4 years ago