Exoplanet vs DR.Orbit

Exoplanets are planets orbiting stars beyond our own solar system. This app allows you to explore all discovered exoplanets, their measured physical properties, their location in the night sky, and their host stars. An interactive model shows you the entire observable universe, all the way from the surface of the Earth to the cosmic microwave background. This app has been developed by a professional astronomer. Main features: * Interactive visualizations and animations. * Physical properties of all detected exoplanets and their host stars, updated on a daily basis. * Stunning 3D model of our Milky Way showing the location of all known exoplanets. You can zoom into any planetary system, explore how the night sky and the constellations look from the surface of other planets, or zoom out and see other local galaxies and galaxy clusters as well as the cosmic microwave background. * Visualizations of exoplanet orbits and the habitable zone. * Choose between the Open Exoplanet Catalogue, the NASA Exoplanet Archive, and the Extrasolar Planet Encyclopedia (exoplanet.eu). * Push notifications are sent out whenever a new planet is discovered. * Augmented reality sky map: point the phone towards the sky to find an exoplanet! * Interactive multi-touch correlation plots. * Solar System planets, major moons, and asteroids are included. * Explore S-Stars orbiting the black hole at the Galactic Center of our Milky Way * Background information about exoplanets and detection methods. * Full support of planets in binary, triple, quadruple systems and orphan planets. * Real-time ray tracing on the GPU.

Demonstration of how a mass (e.g. earth) can orbit around a gravitational well (e.g. sun). Use your finger to push the mass onto a trajectory that results in a stable orbit around the well. Use the options menu to introduce some drag (good to get rid of the mass), to bring up some eye candy or to influence the movement of the mass by tilting your iPad. Physics background: Gravitational forces act between masses. In this demonstration a big stationary mass is situated in the center of the screen. Its location is fixed and it is hidden behind a cap. If you put a small mass onto the screen, it begins accelerating towards the big mass until it disappears under the cap "into the drain". You can prevent your mass from going down the drain by giving it an initial push. Try experimenting with the directions of your pushes. If it is done right, the small mass will be falling around the big mass without - in theory - ever disappearing into the drain. But due to the not very accurate numerical methods used for the calculation of the trajectory of the mass, the reality in this demonstration might be different. This also applies to the background grid on the screen: It does not show the correct wraping of space caused by the big mass in the middle of the screen. Its shape is a compromise between aesthetics and numerics. Link to demonstration video: http://www.youtube.com/watch?v=pwXI-EiZE4o