Armchair Astronomy
What to do on those nights when clouds cover the sky, rain is threatening or, for one reason or another, you just can't see any stars? One answer is armchair astronomy. (more...)Individual Star Identification
It is apparent even to the beginner that some stars are brighter than others. Yet another way to become familiar with the mysteries of the night sky is to focus on these brighter stars and learn what you can about them during each month. (more...)The planets appear
‘The stars of the Winter Triangle are becoming swallowed in the evening twilight as the days lengthen. The Plough, or Big Dipper, is best placed for observation this month, being overhead at 10 p.m. Follow the curving handle of the Plough or Dipper to find brilliant Arcturus, and continue the curve to Spica in the [...]
Pluto’s composition
Pluto’s composition is unknown, but its density (about 2 gm/cm3) indicates that it is probably a mixture of 70% rock and 30% water ice much like Triton. The bright areas of the surface seem to be covered with ices of nitrogen with smaller amounts of (solid) methane and carbon monoxide. The composition of the [...]
Uranus
Uranus, the first planet discovered in modern times, was discovered by William Herschel while systematicly searching the sky with his telescope on March 13, 1781.
Neptune
After the discovery of Uranus, it was noticed that its orbit was not as it should be in accordance with Newton’s laws. It was therefore predicted that another more distant planet must be perturbing Uranus’ orbit.
Monthly General Sky Orientation
Until you gain some familiarity with the night sky it may seem to be a bewildering array of stars whenever you look up. Learning to recognize some of the ancient star patterns called constellations is the best way to bring some sense of order to an initial feeling of confusion.
If you remember to go out [...]
The Earth Satellite Ephemeris Service
This WWW form produces a table which tells where and when to look from a given location to see overflights of the brighter artificial Earth satellites. On a given evening from a dark rural location, dozens of satellites can be located in the sky,
Satellite Tracking
The Russian spacecraft Mir was scheduled to make a visible pass over my house one night. This is not unusual; Mir orbits the earth once in less than ninety minutes.
Deep Sky
The deep sky means dark skies because most of these incredible celestial treasures are faint and diffuse. It takes an experienced eye to see these “faint smudges” and studied observing practice to learn how to let them reveal details of structure through the telescope.
Solar System Live
Welcome to Solar System Live, the interactive Orrery of the Web. You can view the entire Solar System, or just the inner planets (through the orbit of Mars). Controls allow you to set time and date, viewpoint, observing location, orbital elements to track an asteroid or comet, and a variety of other parameters.
Mercury is the closest planet to the Sun
Mercury has been known since at least the time of the Sumerians (3rd millennium BC). It was given two names by the Greeks: Apollo for its apparition as a morning star and Hermes as an evening star.
Total Solar Eclipse of 1999 August 11
On Wednesday, 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon’s umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India where it ends at
THE CENTER FOR STAR FORMATION STUDIES (CSFS)
The Center for Star Formation Studies is a consortium of researchers working together in a coordinated fashion to construct a comprehensive theoretical model of the process of star formation. The Center has been funded by the NASA Astrophysical Theory Program since 1985, and is directed by David
Space Directorate at ARC
The mission of the Space Directorate at ARC is to advance the frontiers of knowledge, technology, and exploration in four areas: Earth System Science; Life Sciences; Space Science;
