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Latest Celestial mechanics Stories

153768c6d5f5099d7c5cb25ba8297ba71
2009-04-15 08:45:00

A Duke University professor and his graduate student have discovered a universal principle that unites the curious interplay of light and shadow on the surface of your morning coffee with the way gravity magnifies and distorts light from distant galaxies. They think scientists will be able to use violations of this principle to map unseen clumps of dark matter in the universe. Light rays naturally reflect off a curve like the inside surface of a coffee cup in a curving, ivy leaf pattern that...

2009-04-10 11:51:00

GREENBELT, Md., April 10 /PRNewswire-USNewswire/ -- Two identical NASA spacecraft are preparing to enter a point in the universe that may eventually answer the question of how our moon was born. (Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO) The spacecraft duet, called Solar Terrestrial Relations Observatory, or STEREO, are nearing a zone known as the Lagrangian points. At these points, the gravity of the sun and Earth combine to form gravitational wells where asteroids...

0ecbb7213b28817ca6d9b892b925d7541
2009-02-25 14:50:00

The patterns of missing asteroids are like the footprints of wandering giant planets preserved in the asteroid belt. University of Arizona scientists have uncovered a curious case of missing asteroids. The main asteroid belt is a zone containing millions of rocky objects between the orbits of Mars and Jupiter. The scientists find that there ought to be more asteroids there than researchers observe. The missing asteroids may be evidence of an event that took place about 4 billion years ago,...

c1c0747f0b51a45ee78b95d0650bf2611
2008-12-22 14:30:00

You look through the telescope. Blink. Shake your head and look again. The planet you expected to see in the eyepiece is not the one that's actually there. Too much eggnog? No, it's just Saturn's crazy Christmas tilt. All year long, the rings of Saturn have been tilting toward Earth and now they are almost perfectly edge-on. The opening angle is a paper-thin 0.8o. Viewed from the side, the normally wide and bright rings have become a shadowy line bisecting Saturn's two hemispheres--a scene of...

2008-09-24 15:00:12

Scientists using data from the U.S. space agency's Wilkinson Microwave Anisotropy Probe have identified an unexpected motion in distant galaxy clusters. National Aeronautics and Space Administration researchers say the cause of the motion might be the gravitational attraction of matter that lies beyond the observable universe. "The clusters show a small but measurable velocity that is independent of the universe's expansion and does not change as distances increase," said lead researcher...

2008-02-11 10:36:42

The two biggest mysteries in cosmology may be one. A new theory says that dark matter and dark energy could arise from a single dark fluid that permeates the whole universe. And this could mean Earth-based dark matter searches will come up empty. Dark matter, as originally hypothesized, is extra hidden mass that astrophysicists calculate is necessary for holding together fast-turning galaxies. The most popular notion is that this matter is made of some yet-to-be-identified particle that has...

2008-01-07 11:45:51

Our universe is a mess — a colossal "cosmic web" of galaxies strung into filaments and tendrils that are millions or billions of light-years long. Although this web's basic structure is resolved, astronomers say understanding it in more detail requires new observatories, better computing and a lot of luck. "When you look into a large telescope, the reality of the cosmic web hits you in the face because you can see how galaxies are organized," said Rodrigo Ibata, an...

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2007-10-26 05:58:26

For almost 75 years, astronomers have believed that the Universe has a large amount of unseen or "Ëœdark' matter, thought to make up about five-sixths of the matter in the cosmos. With the conventional theory of gravitation, based on Newton's ideas and refined by Einstein 92 years ago, dark matter helps to explain the motion of galaxies, and clusters of galaxies, on the largest scales. Now two Canadian researchers at the Perimeter Institute for Theoretical Physics suggest that the...

9cc30b724a6996f121ba68290ac4d6f01
2007-10-24 15:38:11

A narrow belt harboring moonlets as large as football stadiums discovered in Saturn's outermost ring probably resulted when a larger moon was shattered by a wayward asteroid or comet eons ago, according to a University of Colorado at Boulder study. Images taken by a camera onboard the NASA Cassini spacecraft revealed a series of eight propeller-shaped "wakes" in a thin belt of the outermost "A" ring, indicating the presence of corresponding moonlets, said CU-Boulder Research Associate...

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2007-03-09 12:53:31

Astronomers have observed an asteroid change the rate at which it spins for the first time, and shown that this is due to a theoretical effect predicted but never before seen. The international team of scientists from Europe and the United States used a range of telescopes to find that the asteroid is rotating faster by 1 millisecond every year. The acceleration in the rate of rotation is due to heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known...


Latest Celestial mechanics Reference Libraries

Earth Day
2012-04-23 12:12:49

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...

0_526999cd53385fe59877aee7aa5d6eb7
2011-06-20 11:32:36

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 23° 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...

45_b90d45a4e7d89d873d39705549e516ce
2014-01-12 00:00:00

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...

22_438736ec75b9bfaca9b25a90d91dcfaa2
2004-10-19 04:45:44

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...

9_4e0ee555c18ad7f31f4e1417f556ae6a2
2004-10-19 04:45:44

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...

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Word of the Day
omadhaun
  • A fool; a simpleton: a term of abuse common in Ireland and to a less extent in the Gaelic-speaking parts of Scotland.
This word is partly Irish in origin.