Astro Glossary

Naming and Classification of Stars

Naming of Constellations and Asterisms

Naming of Solar System Objects and Features

NASA and the American Space Program

NASA Discovery Missions

A NASA program aimed to explore space with lower-cost, highly focused planetary science investigations designed to enhance our understanding of the solar system. The project’s slogan is “Faster, Better, Cheaper.” Kepler, Mars Pathfinder, Lunar Prospector, and Messenger are just a few of the missions included in the Discovery program.

Near Earth Asteroid Rendezvous (NEAR) Mission

The most extensive study of any minor body to date was provided by NEAR-Shoemaker, which entered orbit around the asteroid Eros on February 14, 2000. It transmitted thousands of images of the asteroid plus extensive measurements of its shape, composition, and gravity. Although it was not designed as a lander, as its fuel neared an end, flight controllers maneuvered it to a gentle touchdown on the asteroid’s surface on February 12, 2001 — the first landing on any asteroid or comet. The craft’s instruments transmitted data from the surface for several days.

Nebulae

A generic term for a fuzzy, diffuse astronomical object. Astronomers have observed four different types of nebulae: H II regions, reflection nebulae, planetary nebulae, and supernova remnants.

Neptune

The eighth planet from the Sun in the solar system. Neptune orbits the Sun at an average distance of 30 AU. The planet has a mass 17.1 times the mass of Earth and a radius 3.9 times the radius of Earth. Neptune is a gas planet made of hydrogen, helium, and methane and has no solid surface. It has a small ring system and 14 known moons, the largest of which is Triton.

Neptune's Moons

The eighth planet from the Sun has 14 known moons as of July 2013. The largest is Triton.

Neutrino

A neutrino is an almost massless particle created in abundance in the nuclear fusion reactions in the hearts of stars. They usually zip through all forms of matter without interacting, making them difficult to detect. (In fact, trillions of them pass through your body every second.) Physicists have built special detectors deep below ground. Neutrinos occasionally zap atoms and molecules in the detector chambers, producing brief flashes of light. From these reactions, physicists can determine the origin of the neutrinos. Astronomers have detected neutrinos produced in supernovas and other powerful events, enhancing our understanding of these objects.