Latest Celestial mechanics Stories
How do astronomers weigh a star that's trillions of miles away and way too big to fit on a bathroom scale? In most cases they can't, although they can get a best estimate using computer models of stellar structure.
In August 1960, NASA launched its first communications satellite, Echo 1 00 and now, fifty years later, NASA has achieved another first by placing the ARTEMIS-P1 spacecraft into a unique orbit behind the moon, but not actually orbiting the moon itself.
Scientists have discovered the first Trojan asteroid.
For decades, researchers have been puzzled over the origins of Saturnâ€™s baby moons, which, according to many models, are so small that they should have been blown to pieces long ago by impacts with asteroids and comets.
Two new and independent studies have put Einstein's General Theory of Relativity to the test like never before.
In an analysis of the past 1.2 million years, UC Santa Barbara geologist Lorraine Lisiecki discovered a pattern that connects the regular changes of the Earth's orbital cycle to changes in the Earth's climate.
Distant galaxy clusters mysteriously stream at a million miles per hour along a path roughly centered on the southern constellations Centaurus and Hydra.
Sloan Digital Survey data provide test that rules out alternative theories of gravity.
GREENBELT, Md., March 10 /PRNewswire-USNewswire/ -- Distant galaxy clusters mysteriously stream at a million miles per hour along a path roughly centered on the southern constellations Centaurus and Hydra.
The Purple Mountain Observatory and the Department of Astronomy, Nanjing University, in Nanjing China-Research, cooperating with the Albert Einstein institute, in Hannover, Germany, put forward a model of the planar co-orbital circular restricted three-body problem, gave the equations of motion, a set of approximation formulas, and an approximate semi-analytical solution.
Earth Day is a day early each year on which events are held to increase awareness and appreciation of the Earth’s natural environment. It is now coordinated worldwide through the Earth Day Network, founded by Dennis Hayes, and is celebrated in more than 175 countries every year. The United Nations designated April 22 as International Mother Earth Day in 2009, and will continue to be held each year on April 22 through at least 2015. The name and concept of Earth Day was allegedly...
The Summer Solstice, or "Midsummer," derived from the Latin sol (sun) and sistere (to stand still), occurs exactly when the Earth's axial tilt is most inclined towards the sun at its maximum of 23Â° 26'. This is the time when the Sun is at its highest, or most northerly, point in the sky in the Northern Hemisphere. Except in the polar regions, where daylight is continuous for many months during the spring and summer, the day on which the Summer solstice occurs is the day of the year with...
Sample Entry: Astronomy is the scientific study of stars, planets, comets, galaxies, and other phenomena that occur outside Earth's atmosphere (e.g. cosmic radiation). Astronomy deals with the evolution, physics, chemical makeup, meteorology, and motion of celestial objects, and also the formation of the universe. The word Astronomy comes from the Greek words astron (meaning "star") and nomos (meaning "law"). Astronomy is one of the oldest sciences. Since the dawn of man, people always...
Autumnal Equinox -- In astronomy, is the equinox at the beginning of autumn in the northern hemisphere: the moment when the sun appears to cross the celestial equator, heading southward. The equinox occurs around September 22-24, varying slightly each year according to the 400 year cycle of leap years in the Gregorian Calendar. In the southern hemisphere, the equinox occurs at the same moment, but at the beginning of spring. There are two conventions for dealing with this: either the...
Satellite -- A satellite is an object that orbits another object. With sufficient tangential velocity, the object does not collide with the primary object it orbits, but maintains a distance from that object as the rate at which it falls towards that object is similar to the rate that it travels away, thus the object orbits the primary object and becomes a satellite. In other words: gravitational force serves as the centripetal force needed to make the object circle the primary...
- In dressmaking, straps running from the belt in front over the shoulders to the belt in the back, with more or less elaboration of trimming and outline. They usually broaden at the shoulder and narrow toward the waist.
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