... 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 . ...

... 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. ... D = SQRT(2Rh) . ... SQRT(2Rh) = (SQRT(2R))(SQRT(h)) . ... Using R = 6371 km, SQRT(2R) = 112.88, giving . ... 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. ...

... As a result, these two Hubble Space Telescope storm watch images from late June and early September offer dramatically contrasting views of the martian surface. ... Would a volcano plume discovered in January above Jupiter's Moon Io still be active months later? To answer this question, the robot spacecraft Galileo currently in orbit around Jupiter was maneuvered to image the plume site during its recent flyby of Io in August. ... The Center of Globular Cluster Omega Centauri . ...

... We have measured this "redshift" for the pink black holes, and allowed for it in our calculations. ... We see this effect in the emission from gas around these pink black holes, but it is far too small an effect to account for the pinkness. Thus the swirling motions of gas around or into the black holes cannot produc the colour. ... At first we thought that these things were normal blue black holes hidden behind clouds of interstellar dust, that absorbed the blue light and made them appear pink. ...

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 | ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2008 March 28 . Across the Universe . Credit: NASA Swift Team , Stefan Immler ( GSFC ) et al. ... But staring toward the northern constellation Bootes on March 19th, even without binoculars or telescope you still could have witnessed a faint, brief, flash of light from a gamma-ray burst . ... About APOD | ...

... For more distant stars we must use other techniques. ... Hence if we see a distant galaxy and can pick out any cepheids lying within it, we can calculate its distance. ... Here then is another method to gauge the size of the Universe and there are yet more. volume at high enough temperature a nuclear fusion reaction sweeps across the white dwarf's surface and eventually we will see a spectacularly bright new star (hence nova) in our skies. ... Why is this relevant to the size of the Universe? ...

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. ...

... GOODS unites extremely deep observations from NASA's Great Observatories, Spitzer , Hubble , and Chandra , ESA's Herschel and XMM-Newton , and from the most powerful ground-based facilities, to survey the distant universe to the faintest flux limits across the electromagnetic spectrum. ... The space-based observations are complemented by ground-based imaging and spectroscopy, including extensive commitments of ESO and NOAO observing time. ... 2010-04-10: Deep VLA 1.4 GHz data for GOODS-North . ...

... 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. ...

Cosmology, Religion & Kansas . ... Cosmology is the study of the origin, current state, and future of our Universe. ... My cosmology tutorial is an attempt to summarize these discoveries. ... These measurements of very small CMB temperature fluctuations over 1% of the sky with a beam size 40 times smaller than COBE's 7 o beam confirm earlier work by a group at Penn & Princeton and data from BOOMERanG's test flight, but provide 3 to 4 times more accuracy. ... Ned Wright's Home Page . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The two eighteenth-century Transits of Venus, in 1761 and 1769, provided a rare opportunity to determine the fundamental unit of astronomical distance: the distance from the Earth to the Sun. The talk will describe how astronomers across the world united in this, the first great international scientific project. ... This text will be replaced . Also available as higher quality mp4 video . ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . ... Visiting Parkes radio telescope . ... Using ground-based trigonometric parallax from our answer to question 3 we can measure 100 pc. so 100/8,500 x 100/1 = 1.2 % of the distance to galactic centre. ... If the Earth orbited the Sun at twice its current distance, what impact would this have on the accuracy of our ground-based astrometry? ...

... Ce qui est admirable, ce n'est pas que le champ des Гїtoiles soit si vaste, c'est que l'homme l'ait mesurГї" , Гїcrivait Anatole France. ... La question reprend souvent l'image du moyen mnГїmotechnique le plus marquant, utilisГї par les vulgarisateurs pour parler de la profondeur des gouffres cosmiques : est-il vrai que nombre d'Гїtoiles visibles dans le ciel sont dГїjГ mortes ? ... La nuit risque d'Г?tre trop courte pour dГїrouler le fil d'Ariane des distances dans l'Univers ! ...

... Are HVCs a common feature of star forming galaxies? ... Consider the typical properties of the smallest HVCs (compact HVCs) found in HIPASS: . Distance . HI Mass . ... At 5 kpc . meager objects ~116 solar masses . ... 1.15 x 10 4 solar masses . ... Putman et al. (2003) found none to 10 7 solar masses. 2% of Sculptor to 3 x 10 6 solar masses by de Blok et al. (2001) found none. ... High velocity gas around other galaxies can be identified from maps and dynamics: . ... 2003) . ...

... STScI-PRC01-04 HUBBLE'S ULTRAVIOLET VIEWS OF NEARBY GALAXIES YIELD CLUES TO EARLY UNIVERSE Astronomers are using these three NASA Hubble Space Telescope images to help tackle the question of why distant galaxies have such odd shapes, appearing markedly different from the typical elliptical and spiral galaxies seen in the nearby universe. ... Light from these galaxies travels great distances (billions of light-years) to reach Earth. ... These stars emit mostly ultraviolet light. ...

... Natalya V. Raguzova and Sergei B. Popov . ... We present a compilative catalogue of Be/X-ray binaries and candidates in the Galaxy and in the Large and Small Magellanic Clouds. This catalogue contains 160 sources and provides information on names and spectral types of optical components, distances, on spin characteristics of neutron stars, and on orbital and X-ray properties of binary systems. ... Be/X-Ray Binaries and candidates in the Galaxy . Galactic sources: comments to the Table 1 . ...

... 2014 Irkutsk-Listvyanka, Russia G r o u p language English Theoretical round General note. ... Footstep of babr. ... Draw in real scale a picture of image of the sunspot "footstep of babr" (see picture and condition of the previous problem) obtained in the focal plane of the LSVT. ... Orion's Belt. ... Estimate at what distance from the Babr the Penguin was, if the shining of the "fourth star of Orion's Belt" approximately corresponds to that of the three others in the picture. ... ISS near Zenith. ...

... NASA's Galaxy Evolution Explorer mission studies the shape, brightness, size and distance of distant galaxies across 10 billion years of cosmic history, giving scientists a wealth of data to help us better understand the origins of the universe. ... This image is a blend of the Galaxy Evolution Explorer's M33 image and another taken by NASA's Spitzer Space Telescope. ... Spitzer, for example, can detect mid-infrared radiation from dust that has absorbed young stars' ultraviolet light. ...

... Bad Astronomy . ... On Thursday, February 15th 2001 (and replayed on March 19), the Fox TV network aired a program called ``Conspiracy Theory: Did We Land on the Moon?'', hosted by X-Files actor Mitch Pileggi. ... Dust around the lander . ... However, it appeals to our common sense: when the sky is black here on Earth, we see stars. ... Bad: The program claims that when the top half of the lander took off from the Moon to bring the astronauts back into orbit, there was no flame from the rocket. ...