A full explanation of the motion of trapped particles would be too abstract and mathematical for this level, but some basic ideas may be described on an intuitive level. The magnetic force on a moving particle is always perpendicular to the motion, as well as to the magnetic field lines. That is why the basic pattern is motion in a circle, around a magnetic field line. ... The best-known periodic motion is the back-and-forth swing of a pendulum, say of a weight suspended by a string (drawing). ...

... This lesson plan supplements the material on the web page . Stargazers and Skywatchers," on disk Ssky.htm , on the web . ... Recognize the daily motion of the Sun across the sky, defining the main directions of east, west, south and north . ... Terms learned: East, west, south, north, horizon, equinox, winter solstice, summer solstice, elevation of the Sun )above the horizon). ... You watch the shadow of a flagpole on a sunny day. ... The noon sun is in the south, so the shadow points north. ...

... Earth, Clouds, Sky, Comet . ... Does a comet's dust tail always orbit behind it? ... Hale-Bopp and Andromeda . ... 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. ...

... Moon Story . ... There is a lesson in the poem, however: We on Earth always see the same side of the Moon because the Moon rotates exactly once and revolves exactly once in a month. ... see activity . ... children learn that the Moon is a sphere, and we always see the same side . ... why do we only see one side of the Moon? ... children learn that the Moon is always facing us because of its monthly cycle of rotation and revolution, and that the Sun affects how much of the Moon we see each night . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . ... Moon . ... Comets and Asteroids . ... What changed our view of Chariklo is the discovery of a ring system around it, the first such feature found around a Solar System body smaller than a gas giant planet. ... Almost certainly the rings were born when a collision with a smaller asteroid blasted millions of tonnes of debris off CharikloтАЩs surface. ... A ring system detected around the Centaur (10199) Chariklo (Braga-Rigas et al.) ...

... High-velocity clouds (HVCs) were discovered by Muller, Oort & Raimond (1963) in the 21-cm line emission of neutral, atomic hydrogen. They are gas clouds which are characterised by high radial velocities incompatible with a participation in the rotation of our Galaxy. ... This suggestion was seized by Braun & Burton (1999) who identified 66 compact high-velocity clouds (CHVCs) with positional and kinematic characteristics being compatible with a distribution across the entire Local Group. ...

... Like the night sky on the Earth, the martian sky hosts a plethora of astronomical phenomena occurring around the clock in a neverending space opera played out for the benefit of robotic and future human observers alike. ... Moons . Mars has two moons, Phobos and Deimos . ... Under the same conditions, Deimos would be as bright as -5, somewhat brighter than the planet Venus appears in Earth's sky. ... The moons are also eclipsed by Mars itself (a situation analogous to lunar eclipses at the Earth). ...

... It s caused by sunlight reflecting off dark cosmic dust in the Solar System. ... By combining the power of four very large telescopes into one super-telescope, astronomers have given themselves the ability to peer closely at almost 100 distant stars. And they discovered ghostly zodiacal light glowing around nine of them exactly as we see it in our own Solar System! ... In fact, out of almost 2000 planets that have been discovered around distant stars, only around 20 have been photographed! ...

... These two images of the Jovian moon Thebe were taken by Galileo's solid state imaging system in November 1996 and June 1997, respectively. ... Thebe, whose longest dimension is approximately 116 kilometers (72 miles) across, is tidally locked so that the same side of the satellite always points towards Jupiter, similar to how the near side of our own Moon always points toward Earth. ... The image on the right emphasizes the side of Thebe that faces away from Jupiter (the "anti-Jupiter" side). ...

... 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...

My research efforts have focused on three areas which are: . More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to the reflex motions of their host stars, and more recently through transits of some planets across the face of the host stars. ... Gravitational microlensing provides a novel technique to look for planets around lens stars, and this is the only technique currently capable of detecting Earth-mass planets. ...

Magnetic Stars, 2011, pp. ... 2010). ... 463 Figure 2: Difference between individual and average spectra in Fig. 1 with phase (vertically, on the right) Figure 3: Almost in a year repeatability of spectral lines form (2009.07.05 and 2010.05.31) in an identical phase 464 CHOUNTONOV 4000 3000 Magnetic field, Bz(G) 2000 1000 0 -1000 -2000 2008/05/23 2010/05/31 -3000 0.0 0.2 0.4 0.6 0.8 1.0 phase Figure 4: Longitudinal magnetic field variations with phase (the sine curve, Rivinius et al., ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : The Moon only shows one face to us because it is not rotating. Better astronomy : The Moon only shows one face because it is rotating, once every time it revolves around the Earth. ... Place the Moon model on the table about 30 centimeters (one foot) away with the X facing the Earth model. ... You'll see that to keep the X facing the Earth model, you have to rotate the Moon model as it goes around the Earth model . ... 2008 Phil Plait. ...

... April 3, 1997 . Earth, Clouds, Sky, Comet . ... Explanation : Does a comet's dust tail always orbit behind it? ... Small ice and dust particles expelled by the comet, however, are literally pushed around by sunlight. ... When the comet is headed inward, sunlight slows down small particles so they orbit behind the comet. When the comet is headed back out though, sunlight speeds them up, so small particles orbit in front of the comet. ... About APOD > . ...

Magnetic Fields around Radio Galaxies Robert Laing (ESO) Laing et al. ... 2008) Negligible depolarization and 2 rotation Almost all Faraday effects must be due to foreground material How to fit depolarization caused by foreground Faraday rotation Complex polarization Rotation measure Integrate over a beam Observed RM for 0 2 rotation and depolarization Faraday rotation and depolarization 5.5 arcsec FWHM Faraday effects at high resolution FWHM = 1.5 ...

... A rough estimation is that in the United States there is one planetarium per 100,000 population, ranging in size from the Hayden Planetarium's 20-meter dome seating 430 people, to three-meter inflatable portable domes where children sit on the floor. ... Together dblo associates make a huge impact in the architecture, interior design and development arena in London. ... With the holidays around the corner what better way to spoil your family than with your very own private home cinema. ...

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "cool stars, stellar systems, and the sun" held at Florence (Italy). ... Recall that the measurements of radial velocity only yield v sin i which in turn gives us M sin i. For most values of i, sin i will be greater than 0.5 and this gives a mass estimate of 0.5 Jupiter masses. ...

... This year's eclipse is unique in duration. ... Although, at the present time, there are 6 solar observatories belonging to leading space agencies in orbit around the Earth, the eclipse of 22 July, 2009, will only be seen by two of them: the Russian CORONAS-PHOTON satellite equipped with TESIS telescopes and Japan's HINODE satellite fitted with an XRT space telescope. ... TESIS will be the first of the two devices (and the very first on Earth) to witness the solar eclipse. ...

In ancient times the solar system was thought to be the whole Universe, so the study of planetary motions was cosmology. ... The planets other than the Moon and Sun generally move West to East through the stars, but occasionally stop and move in the opposite direction ( retrograde motion). In order to explain the retrograde motion of the planets, the geocentric model of the Solar System shown above puts the planets on small circles called epicycles . ...

... The theater "U Nikitskikh Vorot" is located at the Nikitskiye Vorota (Nikita Gate) Square, at the intersection of the Nikitskiy (formerly Suvorovckiy) Boulevard and the Bolshaya Nikitskaya (formerly Gerzen) Street. ... 1) From "Arbatskaya" metro station (any of the two). ... Then walk for 5-6 minutes on the right side of the Nikitskiy Boulevard in the direction of the Pushkinskaya Square until you see the theater's front porch. ... BACK to "U Nikitskikh Vorot" theatre page . ...