... Credit: J. Aasland , Norway Explanation: Does a comet's dust tail always orbit behind it? Since comets rotate, they shed gas and dust in all directions equally. 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. ...

... 2014 September 4 . Cloud, Clusters and Comet Siding Spring . ... Explanation: On October 19th, a good place to watch Comet Siding Spring will be from Mars . Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet. ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . NASA Web Privacy Policy and Important Notices . ...

... Solar System . ... Sun . ... Comets . ... Some get thrown out of the solar system forever, whereas others end up on yet smaller orbits, visiting the inner solar system fairly frequently - such as comet Halley. ... When a comet moves into the inner solar system, this is heated by the Sun, and the ices turn into gas which forms the head or coma of the comet, which may be hundreds of thousands of kilometres across and visible from Earth. The most striking part of many active comets is the tail . ...

Classroom Activity: A Viewgraph Comet . ... This will simulate the Earth's orbit around the Sun. ... Draw several comets along the path with their tails pointing away from the Sun. ... You can create other viewgraphs that have a smaller scale and show several comet orbits or constellations. ... Show how the Earth's orbit is almost circular compared to the comet's. Explain that the Sun is at the focus of the orbits of the planets, asteroids, and comets. ... Actually, comets have two tails. ...

... June 28, 1998 . Comet Hale-Bopp Over Val Parola Pass . ... Explanation: In 1997, Comet Hale-Bopp became much brighter than any surrounding stars. ... Here Comet Hale-Bopp was photographed last March above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo , Italy. Comet Hale-Bopp 's blue ion tail was created when fast moving particles from the solar wind strike ions expelled from the comet's nucleus. ... About APOD > . ...

... self-absorption - the absorption of light shining on an object by a process similar to that which produced the light originally; if a cloud emits less light than it absorbs from other clouds behind it, this net loss of light, termed self-absorption , causes the foreground cloud to appear darker than the background field (the term is from spectroscopy, where small absorption dips sometimes occur in larger emission lines, making the latter look as if it is absorbing part of itself) . ... HISA Main ...

... Главная . ... Новости . ... Проекты . Любителям астрономии . Проект ISON . ... Подробнее . ... Категория: Новости проекта ISON . ... Метки: Космический мусор ,љ Астероиды ,љ Гамма-всплески ,љ Любителям астрономии ,љ Кометы љ . ... Метки: Космический мусор ,љ Астероиды ,љ Любителям астрономии љ . ... Новости обсерваторий проекта] - Обсерватория Кубанского государственного университета от Иванов А - 09.04.2016 11:08:49 . ... 1999-2013 Copyright "Астрономия и Телескопостроение" . ...

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). ...

... The Sun . ... The Corona . ... Solar Wind . 18H.Solar Wind obs. ... Field . ... The first indication that the sun might be emitting a "wind" came from comet tails , observed to point away from the Sun, whether the comet was approaching the Sun or whether it was moving away. ... The corona, like the Earth's atmosphere, is held down by the Sun's gravity. ... The particles at its "roots" stay with the Sun, but those in the high corona flow out with the solar wind, to the Earth's orbit and far beyond. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Moon . Planets . ... Space Flight . ... A gorgeous image of the real ?Lord of the Rings? ... Saturn is a big planet, about nine times as wide as the Earth, so the rings are huge. Let me put them into scale, if Saturn and the rings were moved so that one edge of the rings touched the Earth, then the distance across the rings to the opposite edge would extend more than halfway to the Moon. ... Saturn has a lot of moons. ...

... Bad Astronomy . ... Mad Science . ... Site Info . ... Public Talks . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Who is this guy who calls himself "The Bad Astronomer?" ... First, yes, I am a real live astronomer (when people ask me what astronomers do, I tell them "They astronom !" ... These are emitted by powerful objects like black holes, exploding stars, and super-dense neutrons stars. ... Finally, am I really a bad astronomer? ... 2008 Phil Plait. ...

... Archives . ... If you do not mind the time predictor, it is hard to believe that this is a light curve, time dependent data. ... It?s hard to say this data set is designed for time series analysis apart from the complication in statistical inference due to measurement errors. How to design the statistical study with measurement errors, huge gaps in time, and unequal time intervals is complex and unexplored. ... The following is R output without measurement errors. ... Chandra Blog . ...

... Nebulae are clouds of gas and dust in space. ... These clouds come in many different varieties: some are the remains of dead stars, while others are areas of vigorous star birth, like this one. In fact, two different types can be seen in this striking new image: emission nebulae and reflection nebulae. ... The bluish patch next to the red emission nebula shows light from recently formed stars being scattered in other words, reflected in many different directions by these tiny particles. ...

... An artificial comet holds secrets to Earths life . ... Spacecraft sees cosmic snowstorm during comet encounter . ... The EPOXI mission's recent encounter with Comet 103P/Hartley 2 provided the first images clear enough for scientists to link jets of dust and gas with specific surface features. ... The EPOXI spacecraft revealed a cometary snowstorm created by carbon dioxide jets spewing out tons of golf ball to basketball-sized fluffy ice particles from the peanut-shaped comet's rocky ends. ...

... Home Education Astro Answers Astro Answers ? Icy Visitors: Comets and ISON . ... Astro Answers . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Jaclyn Avidon is a member of the Board of Directors of the Amateur Astronomers Association of New York, the Chair of the AssociationтАЩs School Outreach Committee, and an instructor for the AssociationтАЩs classes. ...

GALAXIES cenA .tiff 40 Bright Radio Galaxy M31.tiff Nikon Andromeda Galaxy (note HII regions in spiral arms) ngc6744.tiff 40 NGC 6744 a face-on spiral clouds_20d.tiff H'blad The Magellanic Clouds our nearest neighbours Lmc_7.tiff Nikon The Large Magellanic Clouds Lmc_zoom.tiff Nikon Detail of previous image smc_7.tiff Nikon The Small Magellanic Clouds smc-zoom.tiff Nikon Detail of previous image 30dor_40_BVR.tiff 40 The 30 Dor ... B [OIII] Halpha trifid.tiff 40" The Trifid Nebula. ...

Dust around Herbig Ae/Be Stars: Porous, Cometary-like Grains? ... This brings up the question, which we try to answer here, of how the grain porosity affects the observational manifestations of the dust shells of HAeBe stars: the excess infrared emission, anomalous extinction in the ultraviolet, and the peculiar behaviour of colour indices and linear polarization during deep brightness minima observed for about 25% of HAeBe stars (UX Ori, WW Vul, etc). ...

... 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. ...

... 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...