... Bad Astronomy . Misconceptions . ... Bad Astronomy : The Moon only shows one face to us because it is not rotating. Better astronomy : The Moon only shows one face because it is rotating, once every time it revolves around the Earth. ... Place the Moon model on the table about 30 centimeters (one foot) away with the X facing the Earth model. ... You'll see that to keep the X facing the Earth model, you have to rotate the Moon model as it goes around the Earth model . ... 2008 Phil Plait. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2007 October 26 . Comet Holmes in Outburst . ... Explanation: Comet 17P/Holmes stunned comet watchers across planet Earth earlier this week. ... Recorded on that date, this view from Tehran, Iran highlights the comet's (enhanced and circled) dramatic new visibility in urban skies. ... About APOD | ... A service of: ASD at NASA / GSFC . ...

... Tonight's Sky . ... The Magazine . ... Star Atlas . ... An artificial comet holds secrets to Earths life . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... The planet has extreme temperature swings and perhaps active lava flows. ... A digital supplement to Astronomy magazine. ... Join TravelQuest International with Astronomy and Discover magazines on one of three great tour options surrounding this celestial spectacle . ... Astronomy Magazine . ...

... These Frontier Fields will combine the power of HST with the natural gravitational telescopes of high-magnification clusters of galaxies. ... We are soliciting gravitational lensing maps for the last four Hubble Frontier Fields clusters (MACSJ0717.5+3745, MACSJ1149.5+2223, AbellS1063, and Abell 370) based upon the exceptionally deep HST FF imaging and other new ancillary data. ... For the full set of proposal instructions and requirements, see the FY16 Frontier Fields Lensing Map Call for Proposals....

... It s because some sunlight bounced off the Earth and dimly lit the side of the Moon that is facing away from the Sun. ... Recently, astronomers used earthshine to help in the search for aliens. Signs of life can be found in the quantities of particular gases in a planet s atmosphere, such as oxygen, ozone, methane and carbon dioxide. And astronomers can work out what gases are in a planet s atmosphere by studying the light that bounces off them their planetshine . ...

The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...

... Our Sun is part of a huge wheel-shaped collection of stars. ... Astronomers have long suspected it was a very massive black hole, and that every galaxy had such a central mass, created early in the history of the universe. ... However, unless that object happens to be headed directly at the black hole (a relatively small target) it will just swing around and fly away again, like a comet making a pass at the Sun. The velocity acquired in falling towards the black hole also helps it escape. ...

The small solids. Asteroids or the small planetes . ... The comets. ... Ceneca the Young.Procuring about the nature.63 y. The comet is a celestial body of a great size, but a rare one... transparent. Sometimes there seen a core and the medium forms a kind of a tail, beard or dishevelled looks. ... The core is an ice body - conglomeration of frosted gas and dust. ... The comet state is variable: ones have the con tails, others the dust tails, and the third have both. ... Meteors and meteorites. ...

... PPTA timeline . ... List of projects . ... PPTA . The Parkes Pulsar Timing Array (PPTA) project is a combined effort from astronomers and students across several institutions dedicated to the very first detection of gravitational waves in the pulsar timing band. ... For a more extensive overview of the PPTA project, please see The Parkes Pulsar Timing Array: What we've done and what we're doing , and in more detail including the first PPTA data release in The Parkes Pulsar Timing Array Project . ...

... Credit: Greg Bacon ( STScI ), NASA Explanation: The last decade saw the profound discovery of many worlds beyond our solar system, but none analogs of our home planet Earth . Exploiting precise observational techniques, astronomers inferred the presence of well over two dozen extrasolar planets , most nearly as massive as gas giant Jupiter or more, in close orbits around sun-like stars. ... Publications with keywords: extrasolar planet - planet - Saturn - planetary system . ... Crescent Saturn . ...

3) Planets and Brown Dwarfs . ... By its nature, this method is most sensitive to massive planets orbiting close to their stars. ... That means that some of the more massive extrasolar planets could actually be brown dwarfs (although the statistics of the finds suggest that most of them are not). ... Another possible difference between brown dwarfs and massive planets is how they are born. ... They would base the fundamental definition on the mode of formation: a planet is built from planetesimals. ...

... Planets . ... Earth Satellites . ... Monthly Sky Notes . ... As the sun sets in the west each evening, Jupiter, the largest planet in our Solar System, is rising in the east in the constellation of Aries, where it is visible throughout the night setting just before sunrise. ... On 28 October the Earth comes between the Sun and Jupiter, in opposition, meaning as the Sun sets in the sky Jupiter will rise. ... Also this month rising into the sky in the early hours of the morning is Mars the Red planet....

... One of this year's largest mass ejections from the Sun's atmosphere was recorded last Sunday by TESIS telescopes aboard the CORONAS-PHOTON satellite ( video - wmv 4.3 MB ). ... Over the course of a week, two gigantic solar prominences were simultaneously ejected from the surface of the Sun. ... Earth will not feel the Sun's influence either. ... The TESIS observatory ї TESIS: www.tesis.lebedev.ru . ... One of this year's largest mass ejections from the Sun's atmosphere (movie WMV, 4.3 MB) . ...

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Jupiter is the largest of the nine planets, more than 10 times the diameter of Earth and more than 300 times its mass. ... The mean density of Earth is 5.245 times that of water. The pull of gravity on Jupiter at the top of the clouds at the equator is 2.4 times as great as gravity's pull at the surface of Earth at the equator. ... It is tipped about 11њ to Jupiter's axis of rotation, similar to Earth's, but it is also offset from the center of Jupiter by about 10,000 kilometers (6,200 miles). ...

... 142,800 Mean density (kg/m^3) .. ... 5.203 Rotation period (length of day in Earth hours).. 9.8 Revolution period (length of year) (in Earth years). 11.86 Obliquity (tilt of axis) (degrees).. 3.08 Orbit inclination (degrees).. 1.3 Orbit eccentricity.. 0.048 Mean surface temperature (K)........................ 120 (cloud tops) Visual geometric albedo.. 0.44 Atmospheric components.............................. 90% hydrogen, 10% helium, .07% methane Rings.. ...

OBSERVATIONS OF COORBITAL SATELLITES OF SATURN Emel'yanov N., Varfolomeev M. Sternberg State Astronomical Institute, Moscow, e-mail : emelia@sai.msu.ru Institut de MИcanique CИleste et de Calcul des иphИmИrides, Paris, e-mail : emelia@imcce.fr Abstract. To improve the orbital parameters and masses of coorbital satellites of Saturn, Janus and Epimetheus, new observations of these satellites are necessary. ... IN: Saturn. ... New observations of Saturn's coorbital satellites" - Icarus. ...

... Events . ... The Event Horizon Telescope: Observing Black Holes with Schwarzschild-Radius Resolution . ... Galaxy lies a super massive black hole - 4 million times more massive . ... Universe to spatially resolve and image a black hole Event Horizon. ... For the much more massive (6 billion solar mass) black hole . ... for assembling a submm-VLBI Event Horizon Telescope. ... emission near the event horizon of super massive black holes. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Asteroid . ... In case you didn't hear about it, which you probably didn't: On Jan. 7, an asteroid 1,000 feet across -- nearly three times the current diameter of Marlon Brando -- barely missed the Earth, which is most likely your planet of residence. ... What if this asteroid had hit the Earth? ... As it happens, the American Astronomical Society was holding a conference in Washington AT THE VERY SAME TIME as the asteroid nearly hit the Earth. ...