... Tonight's Sky . ... Observing . ... Sky this Month . ... Astronomy for Kids . ... Can you explain Mercury's retrograde motion? Do other planets appear to do this also? ... When astronomers talk about retrograde motion, generally they refer to the apparent motion outer planets make as Earth passes them while orbiting the Sun. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Planets . ... Monthly Sky Notes . ... October . ... By admin October 8, 2010 Posted in: Monthly Sky Notes . A giant from close up: an image made using data from the Cassini probe which flew past Jupiter in 2000. ... As it is so far from us, it takes JupiterтАЩs light a significant time to reach us тАУso when you see Jupiter tonight you are seeing it as it was 35€а minutes in the past. ... Posted October 12, 2010 at 11:15 PM . ... Astronotes . ...

home publications > mercury . SEARCH ASP SITE: Match ALL words Match ANY word . ... Publications of the ASP (PASP) . ... A Minor Planet's Night Out . ... Orbiting between Mars and Jupiter are thousands of rocky bodies. ... In 1804 came Juno; in 1807, Vesta. ... Most minor planets, as asteroids are sometimes affectionately called, hum in elliptical orbits between Mars and Jupiter. ... This helps us as we select the Guest Observer, and it helps readers to understand what you studied. ...

The Discovery of the Galilean Satellites . ... Probably the most significent contribution that Galileo Galilei made to science was the discovery of the four satellites around Jupiter that are now named in his honor. Galileo first observed the moons of Jupiter on January 7, 1610 through a homemade telescope. He originally thought he saw three stars near Jupiter, strung out in a line through the planet. ... Galileo's Observations of Jupiter's Moons . ... Jupiter . ...

... Bad Astronomy . ... Mad Science . ... Site Info . ... Public Talks . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Who is this guy who calls himself "The Bad Astronomer?" ... First, yes, I am a real live astronomer (when people ask me what astronomers do, I tell them "They astronom !" ... These are emitted by powerful objects like black holes, exploding stars, and super-dense neutrons stars. ... Finally, am I really a bad astronomer? ... 2008 Phil Plait. ...

Aristarchus of Samos, around 200 BC, proposed that the Earth revolved around the Sun, but found few supporters. ... For a discussion of the discovery of the solar system which includes a "moving picture" illustrating retrograde motion, click here . ... The Sun and Moon, he claimed, obviously moved around Earth. ... The full story of the discovery of the solar system--of Copernicus, Galileo, Tycho and Kepler--is long and would take this discussion too far afield. ... Nicolaus Copernicus . ...

... A discussion of retrograde motion of planets helps the students understand the logic underlying the ideas of both Ptolemy and Copernicus. ... This lesson plan supplements: "The Discovery of the Solar System," section #9c: on disk Ssolsys.htm , on the web . ... Learn about the system proposed by Copernicus, and the way it explained retrograde motion: all planets moved in circles around the Sun, but the ones closer to the Sun always moved faster. ... Did this predict correct planetary motions? ...

... A wordlwide network of amateur and professional astronomers record and time the mutual eclipses and occultations of the Galilean satellites as accurately as possible. ... Already, the acceleration of Io is evident in the data and continued monitoring through this coming season will help pin down the acceleration of the other three satellites. ... From Dr Apostolos Christou, Armagh Observatory: . ... If you want to know the observing times from your location get it by filling in this form . ...

... 2010 October 8 . Two Planet Opposition . ... Explanation: In late September, two planets were opposite the Sun in Earth's sky, Jupiter and Uranus. ... The faint greenish disk of distant planet Uranus is near the upper left corner. Of the tilted planet's 5 larger moons , two can be spotted just above and left of the planet's disk. ... Farthest from Jupiter is Callisto , with Europa and Io all left of the planet's disk, while Ganymede stands alone at the right. ... About APOD | ...

... Neptune, the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. ... Mars: Just The Fiction . ... Like a distant mirror of Earth dwellers' hopes and fears for the future, Mars, the fourth planet from the sun, has inspired profound works of fiction as well. ... Saturn's Rings Seen Sideways . ... Newborn stars lie at the heart of the Orion Nebula, hidden from view by the dust and gas of the giant Orion Molecular Cloud number 1 (OMC-1). ... Shells in the Egg Nebula ....

... The following gallery shows a few of my astronomical images, including pictures of the Moon and the planets taken with the 20 cm refractor of the Argelander-Institut f r Astronomie (AIfA) in Bonn. Planet Venus, observed with the AIfA 20 cm refractor . Planet Mars, observed with the AIfA 20 cm refractor . Planet Jupiter, observed with the AIfA 20 cm refractor . Planet Saturn, observed with the AIfA 20 cm refractor . ... Orion Nebula (M42) observed with the AIfA 20-cm telescope . ...

... Home Observing High Line Jupiter and its moons . ... Lecture Series 2014-2015 . ... AAA Fall Astronomy Class: Astronomy Basics тАУ October-November 2015 . ... Clear Sky Chart . ... This MonthтАЩs Sky тАУ April 2015 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

... Over the past 16 years, astronomers have found more than 700 planets outside of our Solar System. We call these distant worlds exo-planets . ... For example, they can observe how a star dims when a planet passes in front of it. ... In this new method, astronomers use stars like magnifying glasses! ... And astronomers can tell if the star that is acting like a magnifying glass has a planet in orbit around it, as the power of the magnification is even greater! ...

... Our scientific interest is an accuracy of asteroid CCD observations obtained by amateurs and professional astronomers all over in the World. ... These data help us to analyse an accuracy of real CCD positions in the MPC Database. ... Do you test your observations of the small Solar System bodies permanently before sending them to the International Minor Planets' Center? ... Do you know a real accuracy of your positional CCD-observations in comparison with the other observatories' one ? ...

The elements of the numbered minor planets are given with respect to the ecliptic and equinox J2000.0. ... In the Table these values are given to 0.01. ... A dash indicates that there is no opposition in 2015. 1 a.u., 1.017 a.u. 1 a.u., q <= 1.017 a.u.), At stands for Aten type ( a . ... It should be noted that all objects included into the Tables of NEAs, Centaurs and transneptunian objects, and some unusual planets can be also found in the Table of elements and opposition dates of all minor planets. ...

Giant Jupiter. Jupiter . ... Jupiter has no solid surface that is why speaking about its dimensious point the radius of the upper border line of the clouds, where the presseru is about 10 KPa; radius of Jupiter on the equator is 71400 km. ... The Jupiter satellites. ... Nowadays 16 satellites of the Jupiter are known: Adrastea, Mitis, Amaltea , Phina,then 4 Galilei satellites: Io , Europe , Hanimed , Callisto , Leda, Aimalia, Zicitea, Elara, Ananke, Carme, Pasipe and Sinope. ... Jupiter's ring. ...

... HST . ... Hubble Heritage Project . ... HST Peer Review Process . Hubble Fellowships . ... HST Overview . ... Cycle 24 Announcement . ... Proposal ID = 12537 Principle Investigator = David Ehrenreich - Universite de Grenoble I Title = "Venus observed as an extrasolar planet" Time = Jun 5, 2012 15:28:10 - Jun 6, 11:34:00 Targets = MOON-HIPPARCHUS-C Instrument = ACS/WFC, STIS/CCD, WFC3/UVIS . ... Astronomers are beginning to address this question using transits (eclipses) of extrasolar planets. ...

Astronomers Detect Coolest Radio Star . ... The new radio-star is much smaller and colder than our Sun.€а With a surface temperature not much higher than that of a giant planet, and a size comparable to JupiterтАЩs, it is scarcely visible in optical light.€а Yet the radio flares seen at Arecibo show it must have a strong magnetic field, implying that the same could be true of other similar stars. ...

The Astronomy Net . Articles | ... Forums . ... Planets | ... The list below is a live snapshot of where the planets and moon are located right now. ... The links in the left hand column take you to a mirror of the excellent NinePlanets web site where you can read about each planet and much much more. The latest news includes the fact that Pluto is no longer classified as a planet. ... Pluto is now classified as a 'dwarf planet' which includes Ceres and soon to be many others. ... 100 . ...

For more information contact: Brewster LaMacchia 781 937 6300 x312 6th Grade at J. G. Whittier Middle School Looking Up at Night! ... The "Star Party," as these events are called in astronomical circles, was organized by amateur astronomer Brewster LaMacchia and 6th grade teacher Robert Estes. They are both part of Project Astro, a national project that links astronomers with educators and students in the fourth through ninth grades. ... 2 Whittier Middle School Star Party ...