SIMBAD Astronomical Database What is SIMBAD, and what is it not ? % The purpose of Simbad is to provide information on astronomical objects of interest which have been studied in scientific articles. Simbad is a dynamic database, updated every working day. It provides the bibliography, as well as available basic information such as the nature of the object, its coordinates, magnitudes, proper motions and parallax, velocity/redshift, size, spectral or morphological type, and the multitude of names (identifiers) given in the literature. The CDS team also performs cross-identifications based on the compatibility of several parameters, in the limit of a reasonably good astrometry.
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) Explanation: Innermost planet Mercury and a thin crescent Moon are never found far from the Sun in planet Earth's skies. Taken near dusk on April 8, this colorful evening skyscape shows them both setting toward the western horizon just after the Sun.
Magnifying the Universe Embed this infographic on your site! <iframe width="500" height="323" scrolling="no" src=" frameborder="0" allowfullscreen></iframe><br />Copyright 2012. <a href=" the Universe</a> by <a href=" Sleuth</a>. The above is an interactive infographic. We have also developed a complimentary poster that you can view here: Sizes of the Universe poster.
If the Moon Were Only 1 Pixel - A tediously accurate map of the solar system Mercury Venus Earth You Are Here Moon Diamond Planet Found—Part of a "Whole New Class?" The universe just got a bit richer with the discovery of an apparent diamond-rich planet orbiting a nearby star. Dubbed 55 Cancri e, the rocky world is only twice the size of Earth but has eight times its mass—classifying it as a "super Earth," a new study says. First detected crossing in front of its parent star in 2011, the close-in planet orbits its star in only 18 hours. As a result, surface temperatures reach an uninhabitable 3,900 degrees Fahrenheit (2,150 degrees Celsius)—which, along with carbon, make perfect conditions for creating diamonds. NASA's Spitzer Space Telescope collected data on the planet's orbital distance and mass, and resulting computer models created a picture of 55 Cancri e's chemical makeup. "Science fiction has dreamed of diamond planets for many years, so it's amazing that we finally have evidence of its existence in the real universe," said study leader Nikku Madhusudhan, a postdoctoral researcher at Yale University.
Space.com Buy This Infographic as a Full-Size Poster Astronomers have discovered more than 700 alien planets beyond the solar system, and the count is rising all the time. Some are large and hot, and others are smaller and cooler, but scientists are still on the lookout for an Earth twin. They just got closer, with the announcement Dec. 5 of a planet found by NASA's Kepler space telescope to lie in the habitable zone around its star where liquid water, and perhaps life, could exist. You can purchase a 20"x60" poster of this SPACE.com infographic on high-quality 14G Photo Paper from the SPACE.com store here: Buy Poster Embed: Paste the code below into your site.
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. Why take such a long and complex route to Mercury? Although it is not that difficult to fly a spacecraft by Mercury, the task of placing a spacecraft into orbit around the planet is a significant challenge.
Deep Time : A History of the Earth - Interactive Infographic Life on the planet started astonishingly early. The first living organisms, in the current model of evolution, are thought to be Prokaryotes1. The oldest known fossilised prokaryotes have been dated to approximately 3.5 billion years ago, only 1 billion years after the formation of the Earth's crust.