Motions of the Night Sky Related Links
'Starshine' satellite grew from a dream and a theme During the satellite's eight-month orbital lifetime, sunlight flashing from its student-polished mirrors was naked-eye visible against the star background, during certain recurring morning and evening twilight periods, to student and adult observers around the world between the latitudes of 60 degrees north and 60 degrees south. These observers measured the satellite's right ascension and declination by reference to known stars, and they recorded the precise timing of their observations by the use of stopwatches synchronized with international time signals, such as Radio Station WWV in the USA. They used GPS receivers or United States Geological Survey 7 1/2 minute quadrangle maps, or their equivalents in other countries, to measure the latitude, longitude and altitude of their observing sites. They posted their observations and station locations on the Starshine web site to permit computation of the classical elements of the satellite's orbit by the angles only method of LaPlace.
The Sun is our nearest star. Because of that, we can study it better than any other star. And when you do that, you see that the Sun isn't as boring as it may look from earth! In the following `Trip through the Sun' you'll see flames on the Sun larger than ten earths, winds going 1000 mph, and you'll see how the earth eventually will be scorched by the dying Sun.
A center-directed force that causes an object to follow a circular path is called a centripetal force. When you swing a tennis ball from the end of a ribbon, you must pull on the ribbon - exerting a centripetal force. When you let go of the ribbon, the ball travels in a straight path but at a right angle to the ribbon at the moment of release. In other words, the ball follows a tangential path to the circle it was orignially traveling in.
Views of the Solar System [caution -- lots of pop-ups]
Views of the Solar System presents a vivid multimedia adventure unfolding the splendor of the Sun, planets, moons, comets, asteroids, and more. Discover the latest scientific information, or study the history of space exploration, rocketry, early astronauts, space missions, spacecraft through a vast archive of photographs, scientific facts, text, graphics and videos. Views of the Solar System offers enhanced exploration and educational enjoyment of the solar system and beyond.