Rhea ("REE a") is the fourteenth of Saturn 's known satellites and the second largest: orbit : 527,040 km from Saturn diameter : 1530 km mass : 2.49e21 kg . ... Though somewhat larger, Rhea is otherwise very similar to Dione . ... Both rotate synchronously and have dissimilar leading and trailing hemispheres. ... The leading hemisphere is heavily cratered and uniformly bright (left). ... The surface features of Rhea and Dione seem almost identical yet Rhea is twice as massive. ... Saturn .. ...

D ione ( "dy OH nee" ) is the twelfth of Saturn 's known satellites: orbit : 377,400 km from Saturn diameter : 1120 km mass : 1.05e21 kg I n Greek mythology Dione was the mother of Aphrodite (Venus) by Zeus (Jupiter). ... Both rotate synchronously and have dissimilar leading and trailing hemispheres. ... H elene orbits in Dione's leading Lagrange point. more images . ... H elene is in Dione's leading Lagrange point and hence was sometimes refered to as "Dione B". from LANL . ... Saturn .. ...

Rhea . ... Rhea is an icy body with a density of 1.33 gm/cm 3 . The low density indicates that it is composed of a rocky core taking up less than one-third of the moon's mass, with the rest composed of water-ice. ... Rhea is heavily cratered with bright whispy markings. ... The second area, in parts of the polar and equatorial regions, has craters under 40 kilometers (25 miles) in diameter. ... Orbital period (days) . ... Credit: Calvin J. Hamilton) . ... Copyright © 1997 by Calvin J. Hamilton . ...

... HST . ETC 18.0 Known Issues and Features . ... Current . ... HST Peer Review Process . ... HST Overview . Overview . ... Retrieving HST Data . ... HST Science Year in Review . ... STIS . ... Background . ... The current list of HST Calibration Spectra used by the ETC was updated with the preferred set as listed in the CALSPEC website . ... For extended sources in the STIS Imaging ETC and STIS ACQ ETC the following subsection was also added: -------------------------------------------------- . ...

Astronomy Picture of the Day . ... This very sharp telescopic vista features the last object in the modern version of Charles Messier's catalog of bright clusters and nebulae - Messier 110. A dwarf elliptical galaxy, M110 (aka NGC 205) is actually a bright satellite of the large spiral galaxy Andromeda, making M110 a fellow member of the local group of galaxies. Colorful Moon Mosaic . ... The most striking is clearly NGC 3718, a warped spiral galaxy found near picture center. ...

... Tonight's Sky . ... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... The Magazine . ... Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... What to do about satellite trails . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email...

... The lava flow has visibly fewer impact craters than the background terrain, illustrating the general principle that crater numbers can reveal ages of surfaces. ... Dating Small Martian Features . ... The crater-counting system that scientists have used since the 1970s to determine the age of large geologic features on Mars will also allow them to date small features, such as riverbeds and lava flows, according to William K. Hartmann, a senior scientist at the Tucson-based Planetary Science Institute...

... F. Rodionova and E. A. Kozlova . ... Sternberg State Astronomical Institute, 119899, Moscow, Russia; jeanna@sai.msu ru. ... Brown University - Vernadsky Institute Microsymposium 34, October 8-9, 2001, Moscow, Russia . ... Brown University - Vernadsky Institute Microsymposium 38, October 27-29, 2003, Moscow, Russia . ... Brown University - Vernadsky Institute Microsymposium 40, 2004, Moscow, Russia . ... 1 Sternberg State Astronomical Institute Lomonosov Moscow University, Russia; marss8@mail.ru . ...

... gradients dependencies on solar wind parameters and IMF; . ... fate of thermal plasma at the dayside magnetopause. velocity-dispersed injections of the thermal and superthermal ions from LLBL at cusp and cleft (lowest energy VDIS-2 events); . ... outer cusp processes, role of outer cusp indentation, plasma entry (laminar reconnection, turbulent diffusion, others), role of turbulent boundary layer; . how is the magnetosheath plasma heated near magnetopause and cusp? . ... cusp/cleft wave emissions. ...

In 2007-2008, the planet Uranus will reach one of its annual equinoxes for the first time since 1966. As a consequence, its five major satellites orbiting in the equatorial plane will undergo a season of mutual eclipses and occultations very similar to the one that Jupiter's Galilean satellites undergo every 6 years. ... Some of these events occur when Uranus is at conjunction, or the satellite is transiting or too close to the limb of the planet. ... Complete table of events . ...

Next: Coordinate Systems Up: IRAF/PROS Previous: Other Types of Files . A few new features and enhancements to the standard IRAF system have been introduced with the PROS software: . ... Default compound extensions are used by the PROS tasks when no extension is given for the output file name. Most PROS tasks allow the output file name to be defaulted, with the convention that the output file name will be composed of the input `root' name, plus the default extension specific to the task. ...

... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... ESO . ... Survey Telescopes . ... ESO Supernova . ... Star Clusters . ... Stars@ESO . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... ESO 1-metre Schmidt telescope . ... Future Projects . ... This NASA/ESA Hubble Space Telescope image shows the positions of the past, present and predicted future appearances of the Refsdal supernova behind the galaxy cluster?а MACS J1149+2223 . ...

Next: Sky background definition Up: Background Definition Previous: Smoothing spline interpolation . The command BACKGROUND/SMOOTH enables to define the background without previous order definition. This feature is useful for example to correct for the background the image required for the order definition. ... All above methods are implemented in command BACKGROUND/ECHELLE and selected by the echelle keyword BKGMTD . ...

... title='Набор ножей Fiskars 857197' border='0' align='left' width='120' style='margin-right: 20px;' hspace='7' vspace='5'/> . Бренд: FEATURING . Цвет: натуральный . Размер: M . ... Возраст от месяцев: -2147483648 . ... Пол: Унисекс . ... Он отлично сохраняет тепло, позволяя малышам играть на полу. ... Свободный крой, капюшон, удобные карманы и чуть укороченный дизайн - хлопковая куртка Sorrento Jacket поможет Вам создать непринужденный образ и дополнить Ваш лук прохладным летним вечером. ...

View Edit Attributes History Attach Print Search . ... Observing . ... PPTA timeline . ... Editing this wiki . ... RFI . This page is dedicated to identifying the types of RFI that you may encounter whilst observing for P456. ... To upload an image, click 'Edit' at top right, log on, and click 'Attach'. ... Then add a title, description, and the 'Attach' definition and save the page. ... View Edit Attributes History Attach Print Search - Page last modified on February 19, 2014, at 10:59 PM . ...

... The Scientist's Expert Assistant (SEA) is a prototype effort for the Next Generation Space Telescope that uses a combination of artificial intelligence and user interface techniques to explore ways to substantially reduce the time and effort involved in proposal preparation for both scientists and the telescope operations staff. ... At the time, SEA supported only a single observation, had the basics of a graphical exposure calculator and a visual target tuner, and had a very limited expert system. ...

... Laboratory and theoretical modelling of the UV bump on the interstellar extinction curve is a very popular topic in dusty investigations. ... feature is illustrated by Fig. 10 where the profiles were calculated using the model of graphite spheres. Figure 10: Normalized extinction efficiencies for graphite spheres. ... The lower panel shows the summary extinction of two graphite spheres with radii and (from upper panel) taken in equal proportions. ...

XMM-Newton Science Analysis System . ... Meta Index / Home Page / Miscellaneous Algorithms Omdetect has a simple extended-source validation function to recognise scattered-light features and ignore them. The algorithm works by assuming a scattered-light feature consists of a number of connected pixels with values significantly above the background interspersed with pixels not significantly above the background and arranged in a random fashion throughout the source region. ...

Next: Imaging Polarimetry with NICMOS Up: NICMOS Data Calibration and Previous: The Photometric Performance of . ... NICMOSlook and Calnic C . ... Extracting spectra from a large number of NICMOS grism images requires a convenient interactive tool which allows a user to manipulate direct/grism image pairs. ... NICMOSlook and Calnic-C are two programs that were designed to take advantage of the fact that the NICMOS grism mode typically consists of taking both a direct and a grism image. ...

Next: Feature enhancement: normalizing Up: No Title Previous: Feature enhancement: pulsing . The inverse transform is at the core of the best known applications of wavelets: data compaction and numerics. ... Two applications fall within our scope: filtering and denoising. Filtering consists of using only a portion of the wavelet map in the inverse transform process, masking out certain durations. ... Figure 23: Filtered reconstruction of the intermittent signal. ...