... Anonymous The way in which a spacecraft increases or decreases its kinetic energy by swinging around a moving planet is very similar to the way a certain type of water turbine, the Pelton Wheel, extracts energy from a fast jet of water. ... What is the connection with planetary gravity-assist maneuvers ? ... Pelton wheel In particular, if the water overtakes a vane moving at half its speed, then (neglecting friction) it loses all its velocity and just dribbles out of the moving vane. ...

... In FOS polarimetry mode the incoming beam was split into orthogonal polarization components by a Wollaston prism behind the entrance aperture. ... As with non-polarimetric observations, no concurrent WAVECAL exposure was routinely taken with polarimetry data, so the limiting accuracies of the default pipeline polarimetry wavelength calibration are the same as for the non-polarimetry case described earlier ( See "Wavelength Calibration" on page 32-49. ...

... Hale-Bopp in Stereo . ... Earth, Clouds, Sky, Comet . ... Does a comet's dust tail always orbit behind it? ... Which is closer: the comet or the galaxy? ... Presently, for denizens of the Earth's northern hemisphere, this bright comet is certainly a lovely and inspiring sight -- visible here crowning the sky above Cortina d'Ampezzo, Italy on March 20. ... Undaunted by the artificial glow from one of the most famous urban skylines on Earth, comet Hale-Bopp shines above the city of New York, USA. ...

... Low Polar Orbit . ... Different types of satellite orbits have different uses: while the synchronous orbit is best for communication satellites, Lagrangian point orbits help monitor the solar wind before it reaches Earth. ... Many spacecraft use such orbits, e.g. the US Air Force surveillance satellites of the DMSP series, or the series of French Earth-resources spacecraft SPOT . ... If the satellite then starts near a noon-midnight orbit, it will always pass near noon and near midnight. ...

... Magnetic fields, subatomic particles, etc., traveling in different directions fill the universe. Do they deflect or otherwise affect one another? If so, isnт??t the information we get from them distorted? ... Neutrino astronomy, which is still in its infancy, is attractive because neutrinos interact so weakly with matter that few of these distorting effects occur. Get instant access to subscriber content on Astronomy.com! ...

... 2005 December 21 . Sunrise by Season . ... Explanation: Does the Sun always rise in the same direction? ... As the seasons change, the direction toward the rising Sun will change, too. The Sun will always rise and set furthest to the south during the day of Winter Solstice , and furthest to the north during Summer Solstice. ... In many countries, the Winter Solstice brings a change in season , as it is the first day of winter in the North. ... About APOD | ...

To main of Laboratory . The research work and design of optical and optical-electronic devices are carries out by laboratory staff: . ... Lens: . ... In the layout 1 prism systems perform functions of dispersive element, corrector of aberrations, optical reducer. ... Spectral range 200 - 400 nm; . ... Back Forward . ... The main corrector's function are compensation of field aberrations of the main spherical mirror of a telescope (diameter of 600 mm, f'=1200 mm) and increase aperture ratio. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Space Flight . ... Concept Spacecraft . ... By admin September 24, 2010 Posted in: Concept Spacecraft . One of the most grandiose of the vehicles suggested by Cole was the Aldebaran concept, a gigantic nuclear-powered launch vehicle he proposed in 1959. ... Scott Lowther has recently added fascinating scale drawings of this and other nuclear space propulsion concepts at his blog (the Unwanted Blog). ... The Amazing Aldebaran Spacecraft | ...

Allows you to specify a drift scan: motion at a constant velocity along a great circle. ... The path starts at the new object position (though the telescope actually intersects the path later, see Subtleties ). ... Note that the units are always /sec for both axes. ... The velocity along the path is 0.01 /sec. ... The path is assumed to start when you hit the Slew button (more precisely, when the TCC parses the command). However, it takes the telescope awhile to slew to meet the specified path. ...

... Like a last gasp of breath, Sun-like stars puff away their outer layers of gas at the end of their lives. This gas floats away into space and forms beautiful and striking clouds, which are called planetary nebulae (although they have nothing to do with planets). ... Yet, astronomers looking at 100 planetary nebulae in the bulging centre of our Galaxy, the Milky Way have found that most of the bipolar planetary nebulae in this region are acting in the same, strange, way. ...

... The Raw Images . Table 1: List of Viking Orbiter Images of the "Face on Mars" . ... Processing the Face Images . ... In July, 1976, Viking Orbiter 1 was acquiring images of the Cydonia region of Mars as part of the search for potential landing sites for Viking Lander 2. ... Using the height field, it is also possible to view the "Face" from different look directions, by mapping the Viking Orbiter image directly on the the topography and then placing the "viewer" at different locations. ... Mars . ...

... Under conditions of the Earth gravitation we are using the method of semi-natural simulation of linear accelerations in the centrifuges with a mobile cab for simulation of G-loads, originating in a space flight. ... The major factor of the orbital flight, affecting a cosmonaut, is a weightlessness state, which causes essential changes in cardiovascular and vestibular systems operation. ... Under the Earth conditions you can "execute" a short-term space flight according to the following cyclogram: . ...

LIPSKIY-RODIONOVA' LUNAR ANTIPODES AS PRECURSORS OF A REGULAR WAVE PLANETOLOGY G.G.Kochemasov IGEM of the Russian Academy of Sciences, Moscow, Russia kochem@igem.ru / Fax: (009)(095)230 21 79 The first observations of the lunar far side allowed to compare it with the near side and draw very important conclusions in the very beginning of planetary studies based on spacecrafts. ... Celestial bodies are dichotomic. ... The concept of celestial bodies includes Sun (a star) as one of them. ...

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... satvelsrc computes as a function of time the component of the spacecraft velocity vector in the direction of given celestial source. ... SAS_ODF . or named via the generic command line parameters -o or -odfdir (see taskmain for details). ... The source coordinates obtained from the ODF can be overridden with the command line paramters withsrccoord=yes srcra=<ra> srcdec=<dec> and withorthosrc=yes defines a fictitious source in the direction perpendicular to the orbital plane. ...

GRANAT is the Russian x-ray sattelite launched to the high apogee orbit (200,000 km) and operated almost for 10 years (1989 -1999) , carrying out four major instruments: French SIGMA coded-mask hard x-ray telescope (30-1000 keV), Soviet ART-P coded-mask telescope (2??-60?? keV), all-sky monitor WATCH (6-150 keV), and a gamma-burst detector PHEBUS . ... Since September 1994, GRANAT is in the survey mode. ... Explore pages devoted to individual GRANAT instruments (including main scientific results): . ...

I-GALFA View of a Galactic Tangent Region . ... Image featured in NAIC Newsletter #46 . I-GALFA image of hydrogen gas in a tangent region outside the Sagittarius arm. ... Because we are viewing this gas in a direction closely aligned with (tangent to) its orbital motion, it appears to be moving away from us (we are orbiting the Galactic center with a similar speed, but our own motion in a different direction). ... The gas near 60 degrees longitude is being viewed tangent to its orbital motion. ...

... What is there beyond the edge of the universe? ... This is often illustrated by newspaper headlines: "Scientist sees face of God, confirms Big Bang model" (a reference to results from the Cosmic Background Explorer satellite), "Is the cosmos younger than some of the stars it contains? ... The Lone Universe . ... We cannot reproduce it; we cannot take another one and see what happens to it; we cannot compare it to anything else, as astronomers routinely do with planets, stars, and galaxies. ...

... 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...