planetary nebula
21planetary — adj. 1 of or like planets (planetary influence). 2 terrestrial; mundane. 3 wandering; erratic. Phrases and idioms: planetary nebula a ring shaped nebula formed by an expanding shell of gas round a star. Etymology: LL planetarius (as PLANET) …
22nebula — /ˈnɛbjələ / (say nebyuhluh) noun (plural nebulae /ˈnɛbjəli/ (say nebyuhlee) or nebulas) 1. Astronomy a. an irregular, luminous, or dark patch in the sky consisting of interstellar gases and dust. b. a small regular disc resembling (under low… …
23Planetary habitability — is the measure of a planet s or a natural satellite s potential to develop and sustain life. As the existence of life beyond Earth is currently uncertain, planetary habitability is largely an extrapolation of conditions on Earth and the… …
24Planetary migration — occurs when a planet or other stellar satellite interacts with a disk of gas or planetesimals, resulting in the alteration of the satellite s orbital parameters, especially its semi major axis. The generally accepted theory of planet formation… …
25Stingray Nebula — Planetary nebula caption=Hubble Space Telescope photograph of the nebula name = Stingray Nebula type = epoch = J2000 ra = RA|17|16|21.071Harvnb|SIMBAD|2007] dec = DEC| 59|29|23.64 dist ly = 18 kly (5.6 kpc)Harvnb|Parthasarathy|2000] appmag v = 10 …
26Planetary differentiation — In planetary science, planetary differentiation is the process of separating out different constituents of a planetary body as a consequence of their physical or chemical behaviour, where the body develops into compositionally distinct layers;… …
27nebula — (Roget s IV) n. Syn. galaxy, galactic vapor, cloud cluster, nimbus, rarified gas, interstellar dust, luminous vapor. Kinds of nebulae include: spiral, planetary, diffuse, galactic, gaseous, whirlpool, ring; Crab nebula, nebula of Lyra, nebula of… …
28Cat's Eye Nebula — Composite image using optical images from the HST and X ray data from the Chandra X ray Observatory Observation data …
29Ring Nebula — For the Ring Nebula in Barnard s Galaxy, see Ring Nebula (NGC 6822). The Ring Nebula M57, The Ring Nebula. Credit: NASA/STScI/AURA …
30Helix Nebula — For the different but similarly named nebula, see Double Helix Nebula. Eye of God redirects here. For other uses, see Eye of God (disambiguation). Helix Nebula Infrared image of the Helix Nebula, taken by the Spitzer space telescope, 2007 …
