Astronomy, Physics, and Earth Sciences

Milky Way: Stars group together to form galaxies, which are the largest individual objects in the Universe. The Sun, which is a star, together with several hundred billion stars more form our galaxy, the Milky Way. The spectacular galaxy in the image is called M100. The Milky Way, supposedly, looks like M100. What to know more about the Milky Way? http://seds.lpl.arizona.edu/messier/more/mw.html

Elliptical Orbits: The mathematical figure that describes the path followed by an orbiting satellite in space is an ellipse. The orbits of the GPS satellites are ellipses. Actually, the GPS orbits are almost circles (a circle is a special ellipse) and have the Earth in its center. Would you like to play with an orbit simulator? http://www.observe.ivv.nasa.gov/nasa/education/reference/orbits/orbit1.html

Rockets: Launch of a satellite from Kennedy Space Center by the North American Space Agency (NASA).

Space Geodesy Group
Harvard-Smithsonian Center for Astrophysics
60 Garden St, MS 42
Cambridge, MA 02138-1516