... The Round Earth . ... Aristarchus around 270 BC derived the Moon's distance from the duration of a lunar eclipse (Hipparchus later found an independent method). ... Let R be the radius of that circle and T the time it takes the Moon to go around once, about one month. ... Viewed from Earth, a "new Moon" (occuring between the time a thin crescent is last seen before sunrise and the time one is seen shortly after sunset) happens when the Moon in its apparent motion around the sky overtakes the Sun. ...

... Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, nearly making it the record holder. ... A dark Sun hung over Queensland, Australia on Wednesday morning during a much anticipated total solar eclipse. ... As the Moon moves to completely cover the Sun in a total solar eclipse -- like the one set to occur over parts of Australia on Tuesday -- beads of bright sunlight stream around the edge of the Moon...

Hipparchus (and possibly Aristarchus before him) also derived the Moon's distance from the duration of a lunar eclipse . Because the Earth casts a much larger shadow than the Moon, such an eclipse usually darkens the entire Moon, for several hours. ... If the Sun is assumed to be very distant, and if the Moon crosses the middle of the shadow (if not, corrections must be made), the width of the shadow is expected to be about 2r , twice the Earth's radius r . ... Last updated 4 February 1999 Moon. ...

... Resembling a gigantic hubcap in space, a 3,700 light-year-diameter dust disk encircles a 300 million solar-mass black hole in the center of the elliptical galaxy NGC 7052. ... Because the front end of the disk eclipses more stars than the back, it appears darker. ... Despite its size, the disk is 100 times less massive than the black hole. ... The bright spot in the center of the disk is the combined light of stars that have crowded around the black hole due to its strong gravitational pull. ...

... A solar eclipse occurs when the Moon passes in front of the Sun. If the Moon completely covers the Sun, it is a total solar eclipse. ... Although you will not see the 1 August event as a total eclipse in Ireland, you will see a partial eclipse, starting around 9:23 am local time (8:23 UT). The last solar eclipse was seen in Ireland two years ago, on 29 March 2006. ... Friday, 11 July 2008 00:08 . International Year of Astronomy, Ireland National Node . ...

... On the morning of Thursday, 26 February, amid the Gal pagos Islands, the Sun will fade from view. Not the culmination of ancient prophecy, but none less mystical, Earth's small Moon will be executing a slow slide past the enormous Sun. ... And anyone living in southern North America, Central America, northern South America, or on islands and cruise ships in the Caribbean Sea will, weather permitting, have the opportunity to experience the wonder of a solar eclipse. ...

... 2008 August 18 . Baily's Beads near Solar Eclipse Totality . ... As the Moon moves to completely cover the Sun in a total solar eclipse , beads of bright sunlight stream around the edge of the Moon. ... Pictured above, a series of images recorded Baily's beads at times surrounding the recent total solar eclipse visible from Novosibirsk , Russia . ... At the end of totality, as the Sun again emerges from behind the moon, Baily's beads may again be visible -- but now on the other side of the Moon. ...

... HUBBLE UNCOVERS DUST DISK AROUND A MASSIVE BLACK HOLE . Resembling a gigantic hubcap in space, a 3,700 light-year-diameter dust disk encircles a 300 million solar-mass black hole in the center of the elliptical galaxy NGC 7052. ... Because the jets in NGC 7052 are not perpendicular to the disk, it may indicate that the black hole and the dust disk in NGC 7052 do not have a common origin. ... NGC 7052 is located in the constellation of Vulpecula, 191 million light-years from Earth. ...

... This year's eclipse is unique in duration. ... Although, at the present time, there are 6 solar observatories belonging to leading space agencies in orbit around the Earth, the eclipse of 22 July, 2009, will only be seen by two of them: the Russian CORONAS-PHOTON satellite equipped with TESIS telescopes and Japan's HINODE satellite fitted with an XRT space telescope. ... TESIS will be the first of the two devices (and the very first on Earth) to witness the solar eclipse. ...

Astronomy Discussion Forums . ... Total Lunar Eclipse May 15-16 . ... Post Message | ... A total Lunar Eclipse. On the night of May 15-16 the Earth will come between the Sun and the Moon casting a shadow that will slowly cover the Moon. ... The last total Eclipse was on a day where it snowed 10? all day. ... www.astronomy.net . About Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Europa's ocean sits under a thick ice shell. If this ocean covers the moon's solid core, does the shell rotate at a different speed? ... To the best of our knowledge, Europa has an ice shell of a few to as many as 12 miles (20 kilometers) in thickness, underneath which lies a global 60-mile-deep (100km) liquid water ocean. ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "co