... The Earth's orbit is not a perfect, sun-centered circle. At aphelion, the most distant point in Earth's orbit, the Sun is 150 million kilometers away and at perihelion, the closest point, Earth approaches the Sun to within about 147 million kilometers. ... Venus Once Molten Surface . ... This computer reconstruction of the surface of Venus was created from data from the Magellan spacecraft. Magellan orbited Venus and used radar to map our neighboring planet's surface between 1990 and 1994. ...

... 2001 February 22 . 3C294: Distant X-Ray Galaxy Cluster . ... This Chandra Observatory image centered on a radio galaxy cataloged as 3C294 indeed reveals the telltale hot x-ray gas in an hourglass shaped region surrounding the dominant galaxy and shows the presence of a massive galaxy cluster in the distant universe . ... The cluster associated with 3C294 is 10 billion light-years away making it the most distant x-ray galaxy cluster ever detected . ... About APOD | ...

... Spacecraft . ... To space by cannon? Finally, the deep space explorers --spacecraft which break away from the Earth's gravity . ... The "Luna" series of the USSR conducted 7 soft landing of unmanned probes, two of them with wheeled robotic "Lunokhods," and two of those missions returned samples to Earth. Others spacecraft have visited the major planets of the Solar system. ... The Mariner series have explored Venus and Mars--and Mariner 10 even reached Mercury, for three separate encounters! ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

Finally, the deep space explorers --spacecraft which break away from the Earth's gravity . ... The "Luna" series of the USSR conducted 7 soft landing of unmanned probes, two of them with wheeled robotic "Lunokhods," and two of those missions returned samples to Earth. Others spacecraft have visited the major planets of the Solar system. ... The Mariner series have explored Venus and Mars--and Mariner 10 even reached Mercury, for three separate encounters! ... Sojourner" on Mars, its top . ...

... We have simulated the observations of a very distant cluster of galaxies at high redshift. ... The simulations are made for the HST instruments FOC, WFPC II, and the Advanced Camera, and for an 8-m telescope on the ground equipped with adaptive optics. ... A comparison of the fields of view of post-COSTAR HST imaging instruments with the Advanced Camera (AC) and the ground-based adaptive optics camera (AO) is shown in Fig. 1 superimposed on the noise-free cluster simulation. ...

... Moon . ... What can astronomers tell us about the different colors on the surface of Jupiter's moon Europa? ... We can use the colors of Europa s surface to tell us about the chemical compounds that make up the surface and subsurface of the jovian moon. Even before the first spacecraft made a close visit to Europa, astronomers on Earth used telescopes to study the moon and were able to use a technique called spectroscopy to determine that Europa s surface is composed mostly of water ice. ...

Ice Volcanoes Reshape Europa's Chaotic Surface . Ice-spewing volcanoes and the grinding and tearing of tectonic plates have reshaped the chaotic surface of Jupiter's frozen moon Europa, images from NASA's Galileo spacecraft reveal. ... Although the images do not show currently active ice volcanoes or geysers, they do reveal flows of material on the surface that probably originated from them, said Galileo imaging team member Dr. Ronald Greeley of Arizona State University, Tempe. ... Europa . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Image credit:ESO/J.Emerson/VISTA. ... However others are less pessimistic and it has even been claimed that the mysterious ?Wow! signal? received in 1977 originated from the direction M55.б  Sadly, this still unexplained pulse of radio energy originated from a location rather to the northwest of M55 so I doubt if the source was this cluster (if indeed the signal was genuinely of extraterrestrial origin). ... Mysterious Wow! ...

... GSAOI Home . ... Science . ... Deep imaging at J , H , and K is required to identify all stellar objects, brown dwarfs, and planetary mass objects in the central region of the Orion Nebula Cluster down to masses comparable to that of Jupiter. This is required to establish the initial mass function, i.e., the number of stars of each mass that have formed, in this region of intense massive star formation. ... The fields of the GSAOI detectors are shown as four green squares in each frame. ...

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... In summer 1994, the biggest news in astronomy was the collision of comet Shoemaker-Levy 9 with Jupiter. During this school year, Jupiter will charge back into the limelight with the arrival of the Galileo spacecraft (see figure 8 ). On Dec. 7, following a tortuous six-year ramble through the solar system, Galileo will begin its two-year mission studying Jupiter and its gaggle of moons. ... Besides the camera, Galileo will carry instruments capable of identifying minerals on Jupiter's moons. ...

... MAO main . ... The DRAGON globular cluster simulations: a million stars, black holes and gravitational waves . ... simulations of globular clusters with a million stars on the high-performance . ... of stars in globular clusters at unprecedented detail but also shed light into . the dark world of black holes. ... clusters of single and binary black holes. ... of a globular cluster. www.mpa-garching.mpg.de/328833/hl201603 . ... MAO/NASU, 27 Akademika Zabolotnoho St. 03680 Kyiv, Ukraine . ...

... We found that 10 metal-poor globular clusters are greately distinguished for anomalously small masses on the "destruction rate-mass" plain. As it turned out, these poor clusters, situated 15 kpc farther from the Galactic centre, are somewhat younger than the bulk of the metal-poor globulars, and have anomalously red horizontal branches. ... At the same time, deficiency of distant massive clusters is noticeable with increasing distance from the galactic centre. ...

Collins School Star Party - Oct. 5, 1999 Presented by the North Shore Amateur Astronomy Club (NSAAC) For more information: NSAAC: http://www.star.net/people/~nsaac 1.0 Using a telescope Close one eye (use your hand if it's easier) and look straight down into the eyepiece. ... Massive stars use up their fuel much faster - in some cases less than 100 million years. ... Jupiter _____. ... With the chart at left and using the brightest stars as a guide, see if you can find Uranus with binoculars. ...

The planets Jupiter and Venus will make an apparent close approach to each other on the early morning of Friday, 5th November. When Jupiter rises above the eastern horizon at 4.07 a.m. for Northern Ireland viewers, it will be just about one Moon-width away from the much more brilliant Venus. ... In reality, a vast distance will separate the planets. ... FOR FURTHER INFORMATION CONTACT: John McFarland at the Armagh Observatory, College Hill, Armagh, BT61 9DG. ...

Title: A New Model of the Gravitational Lens 0957+561 and a Limit on the Hubble Constant . Authors: Norman A. Grogin , Ramesh Narayan (Harvard Univ.) ... Title: ROSAT/PSPC observation of the distant cluster CL0939+472 . ... Title: Interaction in the Bimodal Galaxy Cluster A3528 . ... Title: Cosmological Implications of Galaxy Cluster Evolution . ... Title: Galaxy Cluster Virial Masses and Omega . ... Matches 201 to 222 from a total of 222 matches for the search pattern galaxy cluster . ...

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

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. ...