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Meteoroid - Meteor (Bolide) - Meteorite
A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classified as ''micrometeoroids'' or ''space dust''. Many are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars. The visible passage of a meteoroid, comet, or asteroid entering Earth's atmosphere is called a meteor, and 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. An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day, which results in an estimated 15,000 tonnes of that material entering the atmosphere each year. A ''meteorite'' is the remains of a meteoroid that has survived the ablation of its surface material du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteoroid Meteor Meteorite
A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classified as ''micrometeoroids'' or ''space dust''. Many are fragments from comets or asteroids, whereas others are impact event, collision impact space debris, debris ejected from bodies such as the Moon or Mars. The visible passage of a meteoroid, comet, or asteroid atmospheric entry, entering Earth's atmosphere is called a meteor, and 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. An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day, which results in an estimated 15,000 tonnes of that material entering the atmosphere each year. A ''meteorite'' is the remains of a meteoroid that has surv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteoroid Track Through Aerogel From EURECA Mission
A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classified as '' micrometeoroids'' or '' space dust''. Many are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars. The visible passage of a meteoroid, comet, or asteroid entering Earth's atmosphere is called a meteor, and 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. An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day, which results in an estimated 15,000 tonnes of that material entering the atmosphere each year. A ''meteorite'' is the remains of a meteoroid that has survived the ablation of its surface materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteor Showers
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] |
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes. Achondrites account for about 8% of meteorites overall, and the majority (about 2/3) of them belong to the HED clan, possibly originating from the crust of asteroid Vesta. Other types include Martian, Lunar, and several types thought to originate from as-yet unidentified asteroids. These groups have been determined on the basis of e.g. the Fe/ Mn chemical ratio and the 17O/18O oxygen isotope ratios, thought to be characteristic "fingerprints" for each parent body. Classification Achondrites are classified into the following groups:O. Richard Norton. The Cambridge encyclopedia of meteorites. UK, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrite
A chondrite is a stony (non-metallic) meteorite that has not been modified by either melting or planetary differentiation, differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%. Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of organic compounds, the Abiogenesis, origin of life and the presence of water on Earth. One of their characteristics is the presence of chondrules (from the Ancient Greek χόνδρος ''chondros'', grain), which are round grains formed in space as molten or partially molten droplets of distinct minerals. Chondrules typically constitute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrule
A chondrule (from Ancient Greek χόνδρος ''chondros'', grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being Accretion (astrophysics), accreted to their parent asteroids. Because chondrites represent one of the oldest solid materials within the Solar System and are believed to be the building blocks of the planetary system, it follows that an understanding of the formation of chondrules is important to understand the initial development of the planetary system. Abundance and size Different kinds of the stony, non-metallic meteorites called chondrites contain different fractions of chondrules (see table below). In general, carbonaceous chondrites contain the smallest percentage (by volume) of chondrules, including the CI chondrites which, paradoxically, do not contain ''any'' chondrules despite their designation as chondrites, whereas ordinary chondrite, ordinary and enstatite chondrite, enstatite chondr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function The Minor Planet Center is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids), calculating their orbits and publishing this information via the '' Minor Planet Circulars''. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory. The MPC runs a number of free online services for observers to assist them in observing minor planets and comets. The complete catalogue of minor planet orbits (sometimes referred to as the "Minor Planet Catalogue") may also be freely downloaded. In addition to astrometric data, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Dust Cloud
The interplanetary dust cloud, or zodiacal cloud (as the source of the zodiacal light), consists of cosmic dust (small particles floating in outer space) that pervades the space between planets within planetary systems, such as the Solar System. This system of particles has been studied for many years in order to understand its nature, origin, and relationship to larger bodies. There are several methods to obtain space dust measurement. In the Solar System, interplanetary dust particles have a role in scattering sunlight and in emitting thermal radiation, which is the most prominent feature of the night sky's radiation, with wavelengths ranging 5–50 μm. The particle sizes of grains characterizing the infrared emission near Earth's orbit typically range 10–100 μm. Microscopic impact craters on lunar rocks returned by the Apollo Program revealed the size distribution of cosmic dust particles bombarding the lunar surface. The ’’Grün’’ distribution of interplan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometeoroid
A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface. The term "micrometeoroid" was officially deprecated by the IAU in 2017, as redundant to meteoroid. Origins and orbits Micrometeoroids are very small pieces of rock or metal broken off from larger chunks of rock and debris often dating back to the birth of the Solar System. Micrometeoroids are extremely common in space. Tiny particles are a major contributor to space weathering processes. When they hit the surface of the Moon, or any airless body ( Mercury, the asteroids, etc.), the resulting melting and vaporization causes darkening and other optical changes in the regolith. Micrometeoroids have less stable orbits than meteoroids, due to their greater surface area to mass ratio. Micrometeoroids that fall to Earth can provide information on millimeter s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Meteor Organization
The International Meteor Organization (IMO) was formally founded in 1988 from predecessor gatherings over many years. IMO has several hundred members and was created in response to an ever-growing need for international cooperation on amateur and professional meteor work. The collection of meteor observations by several methods from all around the world ensures the comprehensive study of meteor showers and their relation to comets and interplanetary dust. IMO publishes a bimonthly journal called ''WGN''WGN = "werkgroepnieuws" (Dutch language), in English as "workgroup news". WGN was initially a circular before it became a journal. and holds an annual International Meteor Conference (IMC) in September.IMO website. See also *American Meteor Society The American Meteor Society, Ltd. (AMS) is a non-profit scientific organization established to encourage and support the research activities of both amateur and professional astronomers who are interested in the field of meteor astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI Unit, SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cell (biology), cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
