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- Near Side
- the side of the Moon that always faces toward the earth. Features on this side are named mainly after the European astronomers who first observed them with telescopes.
- Nebula (pl. nebulae)
- A diffuse mass of interstellar dust and gas.
- Neutrino
- a fundamental particle produced in massive numbers by the nuclear reactions in stars; they are very hard to detect because the vast majority of them pass completely through the Earth without interacting.
- Neutron
- an uncharged subatomic particle that, along with protons, make up atomic nuclei.
- Neutron Star
- the extremely dense core of a star after it has exploded as a supernova. A neutron star has a mass of 1.4 solar masses to as much as three times the mass of the Sun, but may be only a few kilometers across.
- Newton’s Law of Universal Gravitation
- two objects with masses m1 and m2 that have a distance r between their centers attract each other with a force equal to `(G*m1*m2)/r^2`. The Universal Gravitational Constant, G, is equal to 6.672 × 10-11 Nm2/kg2 in SI units.
- Nuclear Fusion
- the process by which lighter elements like hydrogen and helium fuse together to make heavier elements like lithium, carbon, oxygen, etc.
- Nuclear Radiation
- the particles emitted by the decay of unstable nuclei. This type of radiation typically consists of neutrons, electrons/positrons (historically called beta rays) and/or alpha particles (now known to be helium nuclei with mass 4). High energy photons (gamma rays) are also frequently produced – these are particles of very energetic light.
- Nucleosynthesis
- the name given to the process that created atomic nuclei containing more than just a single proton.
- Nucleus (pl. nuclei)
- the core of an atom, generally made up of protons and neutrons.
- Numerical Operations
- mathematical operations like adding, subtracting, multiplying or dividing numbers.
