AST101H1 Lecture Notes - Lecture 1: Dark Energy, Dark Matter, The Cooler

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Damya Souami

Document Summary

Dark matter - 27% (dark matter is the name given to the unseen mass whose gravity governs the observed motions of stars and gas clouds) Dark energy - 68% (dark energy is the name iven to whatever might be causing the expansion of the universe to accelerate) The sum total of all matter and energy; that is, everything within and between all galaxies. Nebula - an interstellar cloud of gas and/or dust. Galaxy - a great island of stars in space, all held together by gravity and orbiting a common center. Star - a large glowing ball of gas that generates heat and light through nuclear fusion. Planet - a moderately large object that orbits a star; it shines by reflect light. Planets may be rocky, icy or gaseous in composition. Moon (or satellite) - an object that orbits a planet. Asteroid - a relatively small and rocky object that orbits a star.