Jupiter loses a stripe - space - 11 May 2010 Jupiter has lost one of its prominent stripes, leaving its southern half looking unusually blank. Scientists are not sure what triggered the disappearance of the band. Jupiter's appearance is usually dominated by two dark bands in its atmosphere – one in the northern hemisphere and one in the southern hemisphere. But recent images taken by amateur astronomers show that the southern band – called the south equatorial belt – has disappeared. The band was present at the end of 2009, right before Jupiter moved too close to the sun in the sky to be observed from Earth. When the planet emerged from the sun's glare again in early April, its south equatorial belt was nowhere to be seen. No cover This is not the first time the south equatorial belt has disappeared. According to this theory, the south equatorial belt disappears when whitish clouds form on top of it, blocking our view of the darker clouds. More From New Scientist Lose weight by tricking body into thinking it's cold (New Scientist)
Earth Earth is the third planet from the Sun. It is the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the world or the Blue Planet.[23] Earth formed approximately 4.54 billion years ago, and life appeared on its surface within its first billion years.[24] Earth's biosphere then significantly altered the atmospheric and other basic physical conditions, which enabled the proliferation of organisms as well as the formation of the ozone layer, which together with Earth's magnetic field blocked harmful solar radiation, and permitted formerly ocean-confined life to move safely to land.[25] The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist. Name and etymology In general English usage, the name earth can be capitalized or spelled in lowercase interchangeably, either when used absolutely or prefixed with "the" (i.e. Heat
Black hole A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. History General relativity
How will Jupiter hold up his pants? | Bad Astronomy | Discover M From Emily at The Planetary Society blog comes word that one of Jupiter’s belts has disappeared… again. This image, by the accomplished amateur astronomer Anthony Wesley, shows what’s up. Usually, the Great Red Spot is accompanied by a dark reddish belt that goes all the way around the planet, like the one in the northern hemisphere you can see in the picture. However, the Southern Equatorial Belt, as it’s called, is gone!This has happened before, in fact. It’s not clear exactly why this sort of thing occurs, though. Jupiter is a weird place. But there is a very cool thing about this: you can see it for yourself! But if you prefer your astronomy to be virtual, you can check out other pictures at Wesley’s site, as well as Astro Bob’s blog. I wonder how long the belt will be gone?
Alpha Centauri Location of Alpha Centauri in Centaurus (right-click on starmap to enlarge) From Earth to Alpha Centauri. Alpha Centauri (α Centauri, α Cen; also known as Rigil Kent /ˈraɪdʒəl ˈkɛnt/—see Names) is the brightest star in the southern constellation of Centaurus, and the third brightest star in the night sky.[10][11] The Alpha Centauri system is located 1.34 parsecs or 4.37 light years from the Sun, making it the closest star system to the Solar System.[12] Although it appears to the unaided eye as a single object, Alpha Centauri is actually a binary star system (designated Alpha Centauri AB or α Cen AB) whose combined visual magnitude of −0.27 makes it the third brightest star (other than the Sun) seen from Earth after the −1.46 magnitude Sirius and the −0.72 magnitude Canopus. Its component stars are named Alpha Centauri A (α Cen A), with 110% of the mass and 151.9% the luminosity of the Sun, and Alpha Centauri B (α Cen B), at 90.7% of the Sun's mass and 44.5% of its luminosity.
Phobos (moon) 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. 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] The unique Kaidun meteorite is thought to be a piece of Phobos, but this has been difficult to verify since little is known about the detailed composition of the moon.[25][26] Labeled Map of Phobos - Moon of Mars (USGS).[30] Tidal deceleration is gradually decreasing the orbital radius of Phobos.
Cis-Neptunian objects Centaurs orbit the Sun between Jupiter and Neptune, often crossing the orbits of the large gas giant planets. There is an emerging sense[2] that the centaurs may simply be objects similar to scattered disc objects that were knocked inwards from the Kuiper belt rather than outwards, making them cis-Neptunian rather than trans-Neptunian scattered-disc objects. Notes[edit] References[edit] Pluto In 2015, the Pluto system is due to be visited by spacecraft for the first time. The New Horizons probe will perform a flyby during which it will attempt to take detailed measurements and images of the plutoid and its moons. Discovery Discovery photographs of Pluto In the 1840s, using Newtonian mechanics, Urbain Le Verrier predicted the position of the then-undiscovered planet Neptune after analysing perturbations in the orbit of Uranus. Subsequent observations of Neptune in the late 19th century caused astronomers to speculate that Uranus' orbit was being disturbed by another planet besides Neptune. In 1906, Percival Lowell, a wealthy Bostonian who had founded the Lowell Observatory in Flagstaff, Arizona in 1894, started an extensive project in search of a possible ninth planet, which he termed "Planet X".[25] By 1909, Lowell and William H. Name The discovery made headlines across the globe. ), but has a circle in place of the middle prong of the trident ( Demise of Planet X Other factors
Pulsar The precise periods of pulsars makes them useful tools. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered around a pulsar, PSR B1257+12. History of observation[edit] Discovery[edit] The first pulsar was observed on November 28, 1967, by Jocelyn Bell Burnell and Antony Hewish.[1][2][3] They observed pulses separated by 1.33 seconds that originated from the same location on the sky, and kept to sidereal time. The word "pulsar" is a contraction of "pulsating star",[7] and first appeared in print in 1968: An entirely novel kind of star came to light on Aug. 6 last year and was referred to, by astronomers, as LGM (Little Green Men). Milestones[edit] In 1974, Joseph Hooton Taylor, Jr. and Russell Hulse discovered for the first time a pulsar in a binary system, PSR B1913+16. In 1992, Aleksander Wolszczan discovered the first extrasolar planets around PSR B1257+12.
Trans-Neptunian Objects A trans-Neptunian object (TNO; also written transneptunian object) is any minor planet in the Solar System that orbits the Sun at a greater average distance (semi-major axis) than Neptune. The first trans-Neptunian object to be discovered was Pluto in 1930. It took until 1992 to discover a second trans-Neptunian object orbiting the Sun directly, (15760) 1992 QB1. Now over 1,200 trans-Neptunian objects appear on the Minor Planet Center's List Of Transneptunian Objects.[1] As of November 2009, two hundred of these have their orbits well-enough determined that they have been given a permanent minor planet designation.[2][3] History[edit] Discovery of Pluto[edit] The orbit of each of the planets is slightly affected by the gravitational influences of the other planets. Pluto was easiest to find because it has the highest apparent magnitude of all known trans-Neptunian objects. Discovery of other trans-Neptunian objects[edit] Distribution and classification[edit] Physical characteristics[edit]
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. Observations by the Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.[25] In 2013, NASA's Curiosity rover discovered that Mars' soil contains between 1.5% and 3% water by mass (about two pints of water per cubic foot or 33 liters per cubic meter, albeit attached to other compounds and thus not freely accessible).[26] Physical characteristics Size comparison of Earth and Mars. Soil
Mercury (planet) First planet from the Sun Mercury's sidereal year (88.0 Earth's day) and sidereal day (58.65 Earth's day) is in a 3:2 ratio. This phenomenon is called spin–orbit resonance and sidereal here means "relative to the stars". Consequently, one solar day (sunrise to sunrise) on Mercury lasts for around 176 Earth's day - twice the planet's sidereal year. Combined with its high orbital eccentricity, the planet surface has widely varying sunlight intensity and temperature, with the equator regions range from −170 °C (−270 °F) at night to 420 °C (790 °F) during sunlight. Nomenclature Physical characteristics Internal structure Surface geology Impact basins and craters Overhead view of Caloris Basin Perspective view of Caloris Basin – high (red); low (blue) Plains Compressional features Volcanism Surface conditions and exosphere Magnetic field and magnetosphere Orbit, rotation, and longitude Orbit of Mercury (2006) Animation of Mercury's and Earth's revolution around the Sun Longitude convention Observation Notes