Umbriel . Uranus II . Umbriel [UM-bree-ul] is the darkest satellite of Uranus. It is about the same size as Ariel and has about the same density. The surface appears to be old with large craters and does not change much from one location to another. Near the top is a puzzling bright ring called the fluorescent cheerio . ... Dark regions are represented as red and bright regions are represented as blue. The two white regions are bright ejecta from two fresh craters. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... 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. ...

Browse the articles below for new ideas for your classroom. Mercury September/October 2005: Astronomy Education and Public Outreach: Steps and Missteps Toward an Emerging Profession (pdf) . Focus on Education articles as they appeared in Mercury: . ... March/April 2000: . ... Education Newswire articles as they appeared in Mercury, by issue. ... January/February 2000 . November/December 1999 . ... March/April 1999 . ... November/December 1998 . ... November/December 1997 . ...

The Many Streams of the Magellanic Stream . ... As a part of the ongoing GALFA survey we have obtained an H I image of a region located at the tip of the Magellanic Stream. ... Figure 1 shows the velocity field of the tip of the Stream. ... Comparison with numerical simulations by Connors et al. (2006) suggests that a 3-way splitting of the main Stream filament may have taken place due to gravitational interactions between the SMC, the LMC, and the Galaxy. ... 2006) . ...

Lunar Libration . Articles | ... Actually, a slight rocking motion, called libration,* makes about 59% of the Moon's surface visible from our planet Earth -- though only 50% at any one time. ... Add to that, the approximate 1.5 degree tilt of the Moon's equator to the ecliptic, and you have the inclination of the Moon's equator to the plane of its orbit around Earth at some 6.5 degrees (5 + 1.5 = 6.5). ... Re-published on Astronomy Net with permission of the author. ... www.astronomy.net . ...

Ariel . ... Ariel [AIR-ee-al] is a relatively small satellite and is the brightest moon of Uranus. ... This image of Ariel shows a world pock-marked with craters. ... This image is a mercator map of Ariel. ... This image is a polar stereographic map of the southern hemisphere of Ariel. ... This image is an orthographic view of Ariel centered at -66 degrees latitude and 316 degrees longitude. ... This image of Ariel is at the same geometry of the highest resolution mosaic of Ariel taken by Voyager. ...

Astronotes Armagh Planetarium's Stellar Blog! ... This image combines orbital imagery with 3-D modelling to show flows that appear in spring and summer on a slope inside Mars' Newton crater. ... Warm season flows on a slope in Newton Crater, possible evidence of salty liquid water active on Mars today. Image credit: NASA) . ... Frozen water is common on and under the surface of Mars but these images are the best evidence to date for the presence of liquid water on the Martian surface today. ...

... NGC 6302: Big Bright Bug Nebula . ... The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. ... Missoula Crater on Mars . ... Comets Bradfield and LINEAR Rising . ... Comet Bradfield is easy to see on the left, but can you find Comet LINEAR on the right? Last week, just before sunrise from the northern hemisphere, two bright comets were visible in the same part of the sky at the same time. ... Comet Bradfield Rising . ...

... ISS: The International Space Station is now making another set of excellent early evening passes over Ireland. ... 2.€а Fantastic Galactic Imagery and a Celestial Extravaganza at the BT Young Scientist and Technology Exhibition 2010, RDS, Dublin. €аIn its 46th year the BT Young Scientist & Technology Exhibition is much more than a competition; it is an unforgettable experience of a lifetime for the students who take part. ... Clear Skies, . ...

... Article text . ... Article should be formatted according to the present rules, using the styles containing in the attached file example.doc . ... For example, article name should be typed in string Here Is the Paper Title , using style "title paper", etc. ... Title part of article Paper Title (style Title Paper . ... It is necessary to use style text paper for the body of article. ... In the text of article there should be links to every Figure and Table: Fig. 1 and Tab. 1 accordingly. ...

The following are some standard questions that PIs have about their solar system target confirmation charts. ... Which apertures are displayed? Each chart is drawn to represent a specific time. ... Ideally, solar system target confirmation charts would show only the aperture that the visit uses; but sometimes it is not that simple. ... We then draw each target in the visit at the start time of the visit unless the target's solar system target windows cannot be satisfied at the start of the visit. ...

... PmWiki / . authors (basic) A key feature of WikiWikiWebs is the ease of creating links in the text of a document. ... To create a link to another page, simply enclose the name of the page inside double square brackets, as in [[wiki sandbox]] or [[installation]] . ... PmWiki creates a link by using the text inside the double brackets. ... PageName|+]] creates a link to PageName and uses that page's title as the link text, eg [[Links|+]] gives Links . ... name|link text]] within the same page, or . ...

T he Siding Spring Survey (SSS) is a Near-Earth Object search program that utilises the 0.5-m Uppsala Schmidt Telescope at Siding Spring Observatory, N.S.W., Australia. ... The mission of the Siding Spring Survey is to contribute to the inventory of near-earth objects (NEOs), or more specifically, the potentially hazardous asteroids (PHAs) and comets (PHOs) that may pose a threat of impact and thus harm to civilization. ... Based on the CSS Mission page . ... Siding Spring Survey Main Page . ...

... You can learn how to use style sheets and how to position HTML content by reading the Guide to Dynamic HTML in Netscape Communicator . ... To return to the top of this page, jump to anchor 1 in this document . ... Jump to the second section A Cold Autumn Day in the mystery "A man from Nowhere". ... If you click on this link, you'll see a confirmation dialog box. ... If you move the mouse over and then away from The Man From Nowhere , a dialog box appears telling you what the link will do. ...

... Moon Phase below . ... ARTICLE: Why the moon always shows us the same face . ... Before you continue reading, you should know that this was not always the case, i.e. the Moon once was rotating with respect to the Earth, so that on every night a terrestrial observer (if there was one, because this was long, long before mankind appeared on our planet, and even before any major animals had appeared) saw another face of the Moon. ... Figure 1 (not to scale) shows how we can imagine the system Earth-Moon...

The sections <Directory> , <Location> and <Files> can contain directives which only apply to specified directories, URLs or files respectively. Also htaccess files can be used inside a directory to apply directives to that directory. ... The order of merging is: . ... If multiple <Directory> sections apply to the same directory they are processed in the configuration file order. ... Using the options in question is only possible inside a <Directory> section (or a .htaccess file). ...

... 2006 October 9 . Mars Rover at Victoria Crater Imaged from Orbit . ... The ability to see the Martian rover from orbit has recently been demonstrated by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter (MRO). ... Last week, MRO imaged the location of Victoria Crater and the rover Opportunity that had just arrived there. ... In the inset image on the upper left, the whole of Victoria Crater was also imaged by MRO. ... About APOD | ...

... SS433 is a close binary system, one star is a supergiant, a second one is a black hole. ... Even a black hole cannot accept such an enormous mass flux, a supercritical accretion disk appears, all the excess gas glows up to several tens of thousands degrees and is ejected off the disk with enormous velocities. ... SAO researchers have found an evidence of the supercritical accretion onto a black hole in SS433, which follows from a brightness variability of the SS433 disk. ...

... This experiment makes use of a novel an sophisticated CCD imaging design whereby by 4 2048x2048 detectors are butted together to form a single 4096x4096 pixel detector system. ... Figure 4 (1.1 Megs) shows an example image from one of the LMC fields that is searched for gravitational microlensing amplification of stellar brightness. ... Figure 5 (124 Kbytes) shows an image of NGC 253, taken with this camera and a 320x512 RCA CCD which has 30 micron size pixels. ... Page 5 . ...