Professional astronomy is split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results.
Astronomy is one of the few sciences in which amateurs play an active role. This is especially true for the discovery and observation of transient events. Amateur astronomers have helped with many important discoveries, such as finding new comets. (Full article...)
Image 13ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 15Portrait of the Flemish astronomer Ferdinand Verbiest who became Head of the Mathematical Board and Director of the Observatory of the Chinese emperor in 1669 (from Astronomer)
Image 16Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 17Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 18The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 19An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 20Segment of the astronomical ceiling of Senenmut's Tomb (circa 1479–1458 BCE), depicting constellations, protective deities, and twenty-four segmented wheels for the hours of the day and the months of the year (from History of astronomy)
Image 22An image of the Cat's Paw Nebula created combining the work of professional and amateur astronomers. The image is the combination of the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile and a 0.4-meter amateur telescope. (from Amateur astronomy)
Image 31Artist conception of the Big Bang cosmological model, the most widely accepted out of all in physical cosmology (neither time nor size to scale) (from Physical cosmology)
Image 34Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 35Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
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The Kreutz sungrazers (/ˈkrɔɪts/ⓘKROYTS) are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. At the far extreme of their orbits, aphelion, Kreutz sungrazers can be a hundred times farther from the Sun than the Earth is, while their distance of closest approach can be less than twice the Sun's radius. They are believed to be fragments of one large comet that broke up several centuries ago and are named for German astronomerHeinrich Kreutz, who first demonstrated that they were related. These sungrazers make their way from the distant outer Solar System to the inner Solar System, to their perihelion point near the Sun, and then leave the inner Solar System in their return trip to their aphelion.
Several members of the Kreutz family have become great comets, occasionally visible near the Sun in the daytime sky. The most recent of these was Comet Ikeya–Seki in 1965, which may have been one of the brightest comets in the last millennium. It has been suggested that another cluster of bright Kreutz system comets may begin to arrive in the inner Solar System in the next few decades. (Full article...)
... that Jessen's icosahedron has been used for both the "Skwish" children's toy and a NASA proposal for a "super ball bot" to cushion space landers on other planets?