... The Round Earth . 8a. The Horizon . ... 9a. Earth orbits Sun? . ... What is the distance D to the horizon? ... Your line of sight to the horizon is a tangent to the Earth--a line which touches the sphere of the Earth at just one point, marked B in the drawing here. ... From the top of Mauna Kea on Hawaii, an extinct volcano about 4 km high (also the site of important astronomical observatories), the horizon should be about twice as distant, 226 km. ... One more: Distance to the horizon on Mars . ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . THE ANCIENT UNIVERSE . c) The Age of Light from the Most Distant Galaxies: The "Time Machine" Effect . ... Thus we are actually seeing these galaxies not as they are today, but as they were billions of years ago. ... The Universe: An Overview | ... The Ancient Universe - The Age of the Expanding Universe - The Age of the Oldest Stars - The Age of Light From Distant Galaxies - The Age of the Chemical Elements | ...

... Debris Disks Surround Distant Suns . ... But inset are actual images of such disks around two nearby stars - AU Microscopii (top left; edge-on) and HD107146 (right: face-on) - as seen by the Hubble Space Telescope. Jupiter and the Moon s Shadowed Horizon . ... Watching the Moon rise through gossamer clouds, she noted, " ... the crescent Moon looked like it was held in the sky by a star just off its shadowed horizon." ... In the Center of the Heart Nebula . ... Filaments Across the Sun . ...

Album : asv-album :: Travels to distant places and countries :: 1999/09 Florence, Rome (Italy) ::14/09 Across the Arno . ... A view on east of Florence from the climb to piazzale Michelangelo. ... Old city wall going from piazza Poggi to Forte di Belvedere. ... Via di Belvedere. ... On costa San Giorgio (going down from Forte di Belvedere to palazzo Pitti). ... Giardino di Boboli, stadium. Palazzo Pitti; view from Giardino di Boboli. ... Palazzo Pitti; view from the top hill of Giardino di Boboli. ...

Hipparchus, who used an eclipse of the Moon to deduce the precession of the equinoxes ( here ), used a total eclipse of the Sun --probably in 129 BC--to estimate how far the Moon was. But he also derived the Moon's distance from a lunar eclipse--see here .) That eclipse was total at the Hellespont--the Dardanelles, part of the narrow strait that separates the European and Asian parts of Turkey--but only 4 / 5 of the Sun were covered in Alexandria of Egypt, further to the south. ...

Blackholes Forum Message . Forums: . ... Black Holes And RedShift . ... Perhaps black holes really are the reproductive means of the universe.Could the black hole of a Quasar red-shift the electromagnetic energy trying to escape it? ... Perhaps black holes treat electromagnetic energy the same way. ... No one really knows enough about Quasars and black holes to say for sure but ask yourself this: Why would all the Quasars in the universe be moving away from the Milky Way? ... www.astronomy.net . ...

... Bad Astronomy . ... Bitesize Astronomy . ... The only motions we see easily are the rising and setting of the Sun, Moon and stars, but that is a reflection of our own Earth's rotation. ... While doing some routine data analysis for for my work with STIS data , I ran across a star that had me baffled. ... I also labeled the stars the same way as in the STIS image. ... In that second image, you can see that the faint star is in about the right place, but the bright star is not even in STIS's field! ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . ... Moon . ... Comets and Asteroids . ... What changed our view of Chariklo is the discovery of a ring system around it, the first such feature found around a Solar System body smaller than a gas giant planet. ... Almost certainly the rings were born when a collision with a smaller asteroid blasted millions of tonnes of debris off CharikloтАЩs surface. ... A ring system detected around the Centaur (10199) Chariklo (Braga-Rigas et al.) ...

... What is a planet? ... When they finally came up with an answer it had big consequences: The number of planets in our Solar System went from nine to eight! ... Then, in 2005, astronomers found an object in the outer Solar System, called Eris, which they thought was bigger than Pluto. ... However, recently astronomers were able to measure the size of the dwarf planet Eris more accurately and they have discovered that it isn t bigger than Pluto after all they re actually about the same size. ...

ATNF Home . About ATNF . ... About ATNF overview . News | ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Information & tools for observers . ... Australia Telescope Online Archive (ATOA) . ... ATCA | ... Australia Telescope 20GHz Survey . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ...