Curated category
Planetary science
- Solar SystemThe Sun holds 99.86% of all the mass in the Solar System. Everything else, the eight planets, the dwarf planets, the moons, the asteroids and comets…
- HED meteoriteHED stands for howardite, eucrite, diogenite. This acronym defines a specific clan of achondrite meteorites that make up about 5% of all falls to Earth.
- GeomorphologyGeomorphology is the scientific study of how Earth's surface came to look the way it does. In the 5th century BC, the Greek historian Herodotus stood at the…
- PlanetA planet is a large, rounded astronomical body, and for centuries the word meant something humble: a point of light that wandered.
- Formation and evolution of the Solar SystemThe formation and evolution of the Solar System began not with a burst of light, but with a quiet collapse. About 4.6 billion years ago, a fragment of a…
- Magnetosphere of JupiterThe magnetosphere of Jupiter is a structure so vast that the Sun itself, visible corona included, would fit inside it with room to spare.
- Planetary differentiationPlanetary differentiation is the reason you are standing on solid ground right now rather than sinking through a uniform mass of mixed rock and metal.
- Definition of planetThe definition of planet has changed several times since ancient Greek astronomers first coined the term. They called wandering lights in the night sky…
- EjectaThe 22nd of July 1980 marked a violent moment at Mount St. Helens when a massive plume of pyroclastic material rose into the sky.
- Frost line (astrophysics)In 1981, astronomer Hayashi calculated that water ice could condense at a distance of 2.7 astronomical units from the Sun.
- Earth massEarth mass is the unit astronomers use to weigh everything from nearby planets to distant worlds orbiting other stars. One number sits at the center of that…