cosmic х- (gamma-) ray line emission
31Antimatter — For other uses, see Antimatter (disambiguation). Antimatter …
32Messier 87 — Virgo A The Messier 87 galaxy. Observation data Epoch J2000 Constellation Virgo Right ascension …
33List of radio propagation topics — This is a list of radio propagation terms. NOTOC A a index A index aa index active prominence active prominence region (APR) active region active surge region (ASR) active dark filament (ADF) AE index Air Force Geophysics Laboratory (AFGL) arch… …
34Outline of astronomy — Mauna Kea in Hawaii is one of the world s premier observatory sites. Pictured is the W. M. Keck Observatory, an optical interferometer. The following outline is provided as an overview of and topical guide to astronomy: Astronomy – studies the… …
35Star — For other uses, see Star (disambiguation) …
36Search for extraterrestrial intelligence — The search for extraterrestrial intelligence is sometimes abbreviated as SETI. For other uses, see SETI (disambiguation). Screen shot of the screensaver for SETI@home, a distributed computing project in which volunteers donate idle computer power …
37dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
38Neutrino — For other uses, see Neutrino (disambiguation). Neutrino/Antineutrino The first use of a hydrogen bubble chamber to detect neutrinos, on November 13, 1970. A neutrino hit a proton in a hydrogen atom. The collision occurred at the point where three …
39SETI — Search for Extra Terrestrial Intelligence (SETI) is the collective name for a number of activities to detect intelligent extraterrestrial life. The general approach of SETI projects is to survey the sky to detect the existence of transmissions… …
40physics — /fiz iks/, n. (used with a sing. v.) the science that deals with matter, energy, motion, and force. [1580 90; see PHYSIC, ICS] * * * I Science that deals with the structure of matter and the interactions between the fundamental constituents of… …
