Space Science - Saturn and Titan Saturn and Titan, side by side Saturn and Titan 5 March 2012 Titan, Saturn’s largest moon at 5150 km across, looks small here, pictured to the right of the gas giant in this infrared image taken by the Cassini spacecraft. Saturn’s rings appear across the top of the image, casting shadows onto the planet across the middle of the image. A much smaller moon, Prometheus, 86 km across, appears as a tiny white speck above the rings in the far upper right of the image. The shadow of another moon, Pandora, 100 km at its widest, can be seen below the ring shadows towards the right side of the planet. Cassini’s wide-angle camera captured the view on 5 January, while it was about 685 000 km from Saturn.
Moon The Moon is in synchronous rotation with Earth, always showing the same face with its near side marked by dark volcanic maria that fill between the bright ancient crustal highlands and the prominent impact craters. It is the second-brightest regularly visible celestial object in Earth's sky (after the Sun), as measured by illuminance on the surface of Earth. Although it can appear a very bright white, its surface is actually dark, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its regular cycle of phases have, since ancient times, made the Moon an important cultural influence on language, calendars, art, and mythology. The Moon's gravitational influence produces the ocean tides and the slight lengthening of the day. The Moon is thought to have formed nearly 4.5 billion years ago, not long after Earth. As of November 2014[update], the Moon is the only celestial body other than Earth on which humans have set foot. Name and etymology
True Saturn True Saturn Date: 6 Oct 2004 While cruising around Saturn in early October 2004, Cassini captured a series of images that have been composed into this large global natural color view of Saturn and its rings. This grand mosaic consists of 126 images acquired in a tile-like fashion, covering one end of Saturn's rings to the other and the entire planet in between. Three images (red, green and blue) were taken of each of the 42 locations, or "footprints," across the planet. The smallest features seen here are 38 km (24 miles) across. The sun-Saturn-Cassini, or phase, angle at the time was 72 degrees; hence, the partial illumination of Saturn in this portrait.
Milky Way Stars and gases at a wide range of distances from the Galactic center orbit at approximately 220 kilometers per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way does not emit or absorb electromagnetic radiation. This mass has been given the name “dark matter”.[22] The rotational period is about 240 million years at the position of the Sun.[9] The Galaxy as a whole is moving at a velocity of approximately 600 km per second with respect to extragalactic frames of reference. The oldest known star in the Galaxy is at least 13.6 billion years old and thus must have formed shortly after the Big Bang.[6] Surrounded by several smaller satellite galaxies, the Milky Way is part of the Local Group of galaxies, which forms a subcomponent of the Virgo Supercluster. Appearance[edit] The Milky Way has a relatively low surface brightness. Size and mass[edit] Schematic illustration showing the galaxy in profile
About Saturn & Its Moons Introduction On June 30, 2004, the Cassini spacecraft entered orbit around Saturn to begin the first in-depth, up-close study of the ringed planet and its domain. As expected, the Saturn System has provided an incredible wealth of opportunities for exploration and discovery. "We're looking at a string of remarkable discoveries -- about Saturn's magnificent rings, its amazing moons, its dynamic magnetosphere and about Titan's surface and atmosphere," says Dr. Cassini's observations of Saturn's largest moon, Titan, have given scientists a glimpse of what Earth might have been like before life evolved. The spray of icy particles from the surface jets collectively forms a towering plume three times taller than the width of Enceladus. The first four years of the Cassini-Huygens saga brought a new dimension of understanding of the complex and diverse Saturn system. Why the "Cassini Solstice Mission?" A complete seasonal period on Saturn has never been studied at this level of detail.
Neptune Neptune is similar in composition to Uranus, and both have compositions which differ from those of the larger gas giants, Jupiter, and Saturn. Neptune's atmosphere, while similar to Jupiter's and Saturn's in that it is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen, contains a higher proportion of "ices" such as water, ammonia, and methane. Astronomers sometimes categorise Uranus and Neptune as "ice giants" in order to emphasise these distinctions.[10] The interior of Neptune, like that of Uranus, is primarily composed of ices and rock.[11] It is possible that the core has a solid surface, but the temperature would be thousands of degrees and the atmospheric pressure crushing.[12] Traces of methane in the outermost regions in part account for the planet's blue appearance.[13] In contrast to the hazy, relatively featureless atmosphere of Uranus, Neptune's atmosphere is notable for its active and visible weather patterns. History Naming
Cassini Virtual Tour Cassini Virtual Tour [Editor's note, March 2011: for expanded development of this project, please see [Editor's note, July 2010: The data that drives the "Mission Mode" of CASSIE was made available through the first days of July 2010. It was deemed cost prohibitive to update, so this page and CASSIE itself remains active as an archive reference until a suitable replacement becomes available.] If this is the first time you've tried CASSIE, when you click on the button below it will automatically download and install the needed software (a free plug-in to your web-browser) and real Cassini mission data. When CASSIE appears in your web browser, click on one of the three Modes located in the large tab along the bottom of the screen. Windows and Mac OS only Further description
Phobos Phobos (systematic designation: Mars I) is the larger and closer of the two natural satellites of Mars. Both moons were discovered in 1877. Phobos has dimensions of 27 × 22 × 18 km,[1] and is too small to be rounded under its own gravity. Its surface area is slightly less than the land area of Delaware. Phobos does not have an atmosphere due to low mass and low gravity.[10] It is one of the least reflective bodies in the Solar System. Faint dust rings produced by Phobos and Deimos have long been predicted but attempts to observe these rings have, to date, failed.[23] Recent images from Mars Global Surveyor indicate that Phobos is covered with a layer of fine-grained regolith at least 100 meters thick; it is hypothesized to have been created by impacts from other bodies, but it is not known how the material stuck to an object with almost no gravity.[24] Labeled Map of Phobos - Moon of Mars (USGS).[30] Tidal deceleration is gradually decreasing the orbital radius of Phobos.
Mercury Mercury is gravitationally locked and rotates in a way that is unique in the Solar System. As seen relative to the fixed stars, it rotates exactly three times for every two revolutions[b] it makes around its orbit.[13] As seen from the Sun, in a frame of reference that rotates with the orbital motion, it appears to rotate only once every two Mercurian years. An observer on Mercury would therefore see only one day every two years. Because Mercury's orbit lies within Earth's orbit (as does Venus's), it can appear in Earth's sky in the morning or the evening, but not in the middle of the night. Also, like Venus and the Moon, it displays a complete range of phases as it moves around its orbit relative to Earth. Internal structure Internal structure of Mercury: 1. Mercury's density can be used to infer details of its inner structure. Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this. Plains
Asteriod Belt The asteroid belt (shown in white) is located between the orbits of Mars and Jupiter. History of observation[edit] In an anonymous footnote to his 1766 translation of Charles Bonnet's Contemplation de la Nature,[8] the astronomer Johann Daniel Titius of Wittenberg[9][10] noted an apparent pattern in the layout of the planets. If one began a numerical sequence at 0, then included 3, 6, 12, 24, 48, etc., doubling each time, and added four to each number and divided by 10, this produced a remarkably close approximation to the radii of the orbits of the known planets as measured in astronomical units. In 1800 the astronomer Baron Franz Xaver von Zach recruited 24 of his fellows into a club, the Vereinigte Astronomische Gesellschaft ("United Astronomical Society") which he informally dubbed the "Lilienthal Society"[11] for its meetings in Lilienthal, a small city near Bremen. Origin[edit] Formation[edit] Evolution[edit] The asteroids are not samples of the primordial Solar System.
Mars Animation of Mars' rotation from the vantage of an observer who moves south, then north, to hover over both poles, showing the planet's major topographic features. Mars is currently host to five functioning spacecraft: three in orbit – the Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter – and two on the surface – Mars Exploration Rover Opportunity and the Mars Science Laboratory Curiosity. Defunct spacecraft on the surface include MER-A Spirit and several other inert landers and rovers such as the Phoenix lander, which completed its mission in 2008. Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Physical characteristics Size comparison of Earth and Mars. Internal structure Surface geology During the Solar System's formation, Mars was created as the result of a stochastic process of run-away accretion out of the protoplanetary disk that orbited the Sun. This Mars rock revealed its bluish-gray interior to Mars Science Laboratory[40] Soil