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Pi Puppids
The pi Puppids are a meteor shower associated with the comet 26P/Grigg-Skjellerup. The meteor stream was viewable around April 23 but only in years around the parent comet's perihelion date, the last being in 2003. However, as the planet Jupiter has now perturbed the comet's perihelion to beyond Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...'s orbit it is uncertain how strong the shower will be in the future. The pi Puppids get their name because their radiant appears to lie in the constellation Puppis, at around Right ascension 112 degrees and Declination −45 degrees. This made them only visible to southern observers. They were discovered in 1972 and have been observed about every 5 years - at each perihelion passage of the comet - but often at very low rates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puppis
Puppis is a constellation in the southern sky. Puppis, the Latin translation of "poop deck", was originally part of an over-large constellation Argo Navis (the ship of Jason and the Argonauts), which centuries after its initial description, was divided into three parts, the other two being Carina (the keel and hull), and Vela (the sails of the ship). Puppis is the largest of the three constellations in square degrees. It is one of the 88 modern constellations recognized by the International Astronomical Union. Features Argo Navis was sub-divided into three sections in 1752 by the French astronomer Nicolas Louis de Lacaille, including Argûs in puppi. Despite the division, Lacaille kept a single set of Bayer designations for the whole constellation, Argo. Therefore, Carina has the α, β, and ε, Vela has γ and δ, Puppis has ζ, and so on. In the 19th century, these three sections of Argo became established as separate constellations and were formally included in the list of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteor Shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller than a grain of sand, so almost all of them disintegrate and never hit the Earth's surface. Very intense or unusual meteor showers are known as meteor outbursts and meteor storms, which produce at least 1,000 meteors an hour, most notably from the Leonids. The Meteor Data Centre lists over 900 suspected meteor showers of which about 100 are well established. Several organizations point to viewing opportunities on the Internet. NASA maintains a daily map of active meteor showers. Historical developments A meteor shower in August 1583 was recorded in the Timbuktu manuscripts.Abraham, Curtis"Stars of the Sahara" ''New Scientist'', issue 2617,15 August 2007, page 39–41 In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently bright, a comet may be seen from Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions. Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteor
A meteoroid () is a small rocky or metallic body in outer space. Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars. When a meteoroid, comet, or asteroid enters Earth's atmosphere at a speed typically in excess of , aerodynamic heating of that object produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor or "shooting star". Meteors typically become visible when they are about 100 km above sea level. A series of many meteors appearing seconds or minutes apart and appearing to originate from the same fixed point in the sky is called a meteor shower. A meteorite is the remains of a meteoroid th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perihelion
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth the mass of the Sun. Jupiter is the List of brightest natural objects in the sky, third brightest natural object in the Earth's night sky after the Moon and Venus, and it has been observed since Pre-history, prehistoric times. It was named after the Jupiter (mythology), Roman god Jupiter, the king of the gods. Jupiter is primarily composed of hydrogen, but helium constitutes one-quarter of its mass and one-tenth of its volume. It probably has a rocky core of heavier elements, but, like the other giant planets in the Solar System, it lacks a well-defined solid surface. The ongoing contraction of Jupiter's interior generates more heat than it receives from the Sun. Because of its rapid rotation, the planet' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiant (meteor Shower)
The radiant or apparent radiant of a meteor shower is the celestial point in the sky from which (from the point of view of a terrestrial observer) the paths of meteors appear to originate. The Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus. Meteor paths appear at random locations in the sky, but the apparent paths of two or more meteors from the same shower will converge at the radiant. The radiant is the vanishing point of the meteor paths, which are parallel lines in three-dimensional space, as seen from the perspective of the observer, who views a two-dimensional projection against the sky. The geometric effect is identical to crepuscular rays, where parallel sunbeams appear to converge. A meteor that does not point back to the known radiant for a given shower is known as a ''sporadic'' and is not considered part of that shower. Shower meteors may appear a short time before the radiant has risen in the observer's eas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ascension
Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point in question above the earth. When paired with declination, these astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' ( la, ascensio recta), "''Ascensio recta'' Solis, stellæ, aut alterius cujusdam signi, est gradus æquatorus cum quo simul exoritur in sphæra recta"; roughly translated, "''Right ascension'' of the Sun, stars, or any other sign, is the degree of the equator that rises together in a right sphere" refers to the ''ascension'', or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator intersects the horizon at a right angle. It contrasts with ''oblique ascension'', the point on the celestial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Declination
In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of the celestial equator, along the hour circle passing through the point in question. The root of the word ''declination'' (Latin, ''declinatio'') means "a bending away" or "a bending down". It comes from the same root as the words ''incline'' ("bend foward") and ''recline'' ("bend backward"). In some 18th and 19th century astronomical texts, declination is given as ''North Pole Distance'' (N.P.D.), which is equivalent to 90 – (declination). For instance an object marked as declination −5 would have an N.P.D. of 95, and a declination of −90 (the south celestial pole) would have an N.P.D. of 180. Explanation Declination in astronomy is comparable to geographic latitude, projected onto the celestial sphere, and right ascension is like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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