Astronomie - MESSENGER arrive aux abords de Mercure - AstroSurf Envoyé 03-01-2008 19:42 j'ai relevé ces precisions sur le site, où il s'avère que c'est bien pour diminuer la vitesse de la sonde afin qu'elle soit capturée par Mercure...Mais ça ne répond pas tout à fait à la question : pourquoi peut-on envoyer directement une sonde en orbite de Mars et pas de Mercure ? Rôle joué par le Soleil, faible masse de Mercure ?? "5.
Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2016 April 15 Mercury and Crescent Moon Set Image Credit & Copyright: Miguel Claro (TWAN, Dark Sky Alqueva)
Image Resources at the NSSDC General Image Services Specialized Image Services Planetary Data Visualization Visual and Technical Arts Laboratory Other NASA Data Archive/Service Centers The Scale of the Universe Light travels at 300,000 kilometres per second (186,000 miles per second). In one second, a beam of light can travel SEVEN TIMES around the Earth. This table shows a number of distances to various objects expressed in terms of how long a beam of light takes to travel that distance. Time scales longer than the age of the Universe are possible because of the expansion of the Universe. The scale of the Universe and our place in it are well summarised in Monty Python's Galaxy Song.
Spitzer Space Telescope The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space observatory launched in 2003. It is the fourth and final of the NASA Great Observatories program. The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted. Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2017 February 24 NGC 3621: Far Beyond the Local Group Image Credit & Copyright: Processing - Robert Gendler, Roberto Colombari Data - Hubble Legacy Archive, European Southern Observatory, et al. Explanation: Far beyond the local group of galaxies lies NGC 3621, some 22 million light-years away. Found in the multi-headed southern constellation Hydra, the winding spiral arms of this gorgeous island universe are loaded with luminous blue star clusters, pinkish starforming regions, and dark dust lanes.
Hubble data predicts Milky Way galactic collision When Galaxies Collide! It sounds like an early science fiction novel. However, analysis of Hubble measurements shows that our own Milky Way galaxy is moving toward a head-on collision with our nearest neighbor, the Andromeda galaxy (also known as M31). The collision will start in about four billion years, and over the following three billion years the two spiral galaxies will coalesce into a large elliptical galaxy. SkyServer DR7 Tools for Visual Exploration The visual exploration tools built for the SkyServer make it easy to visualize and explore detailed astronomical data in regions of the sky covered by the Sloan Digital Sky Survey. One can specify regions of interest by central position and size. An underlying web service then combines the relevant images to form a JPEG mosaic* at the requested wide range of resolutions. One can overlay additional useful information, including: boundaries of survey fields and aperture plates, outlines of individual objects and data quality masks, and locations of photometric and spectroscopic objects. The tools can also search for lists of known objects, provide links for detailed information, and formulate new database queries.
Watch the Program (full-screen) The Elegant Universe: Part 3 PBS Airdate: November 4, 2003 NARRATOR: Now, on NOVA, take a thrill ride into a world stranger than science fiction, where you play the game by breaking some rules, where a new view of the universe pushes you beyond the limits of your wildest imagination. This is the world of "string theory," a way of describing every force and all matter from an atom to earth, to the end of the galaxies—from the birth of time to its final tick, in a single theory, a "Theory of Everything."