... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2012 July 18 . A Hole in Mars . Image Credit: NASA , JPL , U. Arizona . Explanation: What created this unusual hole in Mars? ... The hole appears to be an opening to an underground cavern, partly illuminated on the image right. ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . ...

... A big bright star near the center of the red region appears white hot and emits light so energetic . A Distant Cluster of Galaxies . ... In this 1994 Hubble Space Telescope photograph, every bright object is a galaxy. Oddly - most of them are spiral galaxies. This rich cluster of galaxies, named CL 0939+4713, is almost half way across the visible universe. ... In this dramatic picture, spiral galaxy NGC 5091 appears in the foreground. ... Can you see through the spiral galaxy? ...

... Table files like the ones created in the section on imcnts can be displayed, printed and manipulated using the tasks contained in the stsdas.ttools package. ... sp> tables # Load the relevant package ta> tprint rp90_cnt prpar=yes # .tab extension assumed # the hidden parameter prpar is set to display the header # as well as the data ta> tprint rp90_cnt # Displays only the data info ta> tprint rp90_cnt prdata- prpar+ # Displays only the header info ta> tprint rp90_cnt prparam=yes | ...

The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...