Granules are regions of the sun where hot solar material comes to the solar surface. Granules are about 600 miles (1,000 km) across and only exist for about 5 to 10 minutes before they fade away. It is almost as though the surface of the Sun is bubbling like a pot of boiling water.
Gray granules covering most of the crater floor surrounding Opportunity contain hematite, said Dr. Phil Christensen, lead scientist for both rovers' miniature thermal emission spectrometers, which are infrared-sensing instruments used for identifying rock types from a distance.
Each granule forms the topmost part of a solar convection cell. Spectroscopic observation within and around the bright regions shows direct evidence for the upward motion of gas as it "boils" up from within. This evidence proves that convection really does occur just below the photosphere.
Figure 2. Granules on the surface of the Sun. Each bubble is around 1000 km in size. The differences in the shades is due to temperature differences, with lighter areas being hotter. Image courtesy of NASA's Solar Physics Research Site.
Granule A roughly circular region on the Sun whose bright center indicates hot gases rising to the surface, and whose dark edges indicate cooled gases that are descending towards the interior.
granules Small bright features of the photosphere of the sun, covering 50 to 60 percent of the surface. They have been likened in appearance to rice grains. graph A diagram indicating the relationship between two or more variables.
granule (solar) small, roundish patch of dark nebulosity that may be the precursor of a protostar. grating optical surface (transmissive or reflective) upon which is ruled a large number of finely spaced grooves.
Individual granules, which represent the tops of small convection cells, are 200 to 2000 km in diameter and have lifetimes of 8 to 10 minutes. Greenwich Mean Time (GMT). See Coordinated Universal Time. green line. A coronal emission line at 530.
Hot gas rises in the middle of each granule bringing energy from the interior to the surface and sinks back down on the border of a granule. The hot gas rising in the center is brighter than the cooler gas sinking at the borders. Each granule will last for about 8 minutes.
Solar Atmosphere ...
Intergranular - angular interstices between feldspars occupied by pyroxene granules (very small grains).
Intersertal - interstices filled with a mixture of glass and some pyroxene.
Matrix, groundmass, or mesostasis - fine-grained or glassy medium in which large grains are set.
Traditionally, active carbons are made in particular form as powders or fine granules less than 1.0 mm in size with an average diameter between .15 and .25 mm. Thus they present a large surface to volume ratio with a small diffusion distance.
The Sun's photosphere is composed of convection cells called granules-cells of gas each approximately 1000 kilometres in diameter with hot rising gas in the center and cooler gases falling in the narrow spaces between them.
How fast are these bits and pieces and granules moving around in the stream? And maybe it ain't the earth getting hit by meteoroids so much as these little bits and pieces just floating around out there are getting slammed by the earth as it comes whizzing by, rotating in its orbit around the sun.
The granulation consists of about one million bright convection cells, called granules. The bright centre of each granule indicates hot plasma rising to the photosphere, and its dark edges indicate cooled material descending towards the interior.
February 1, 2004: The crater floor surrounding Opportunity is covered with gray granules containing hematite. In fact, the idea that the mineral hematite existed on Meridiani Planum was the principal reason the site was selected by NASA for exploration.
Solar faculae are bright spots that form in the canyons between solar granules, short-lived convection cells several thousand kilometers across that constantly form and dissipate over timescales of several minutes.
Convective cells (about 1000 km in diameter) in the solar photosphere. Each granule lasts about 5 minutes on the average and represents a temperature roughly 300° higher than the surrounding dark areas. At any one time, granules cover about one-third of the solar photosphere. [H76]
surface (10,000 degrees F.). Notice how the surface looks dimpled everywhere you look: each of these granules is the top of a convection cell where hot fluid rises up, spreads out, then sinks back over about 20 minutes. Each granule is about 620 miles across. Less «
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Individual granules last for a few minutes and are thought to be the tops of convection cells.
The collapse of an object when its internal forces are no longer able to support it against the force of gravity.
L chondrite - a chondrite (a stony meteorite containing small, round, silicate granules called chondrules) that has a low amount of iron.
Lagrange point - One of five locations in space relative to two bodies where less massive body can maintain a stable orbit around a common center of mass.
The surface of the Sun can be seen, through a telescope (SEE WARNING), to have a granular appearance. These granules are the convection cells that carry the energy from below the apparent surface.
Short-lived (lifetime from rising to falling is about 15 minutes) jets vertical to the solar surface that are several thousand kilometers long and about 1 kilometer thick. The birth rate is comparable to granules and there are hundreds of thousands of spicules on the Sun.
Spectra of the centers of the granules shows these regions to be a few hundred Kelvin hotter than the surrounding darker lanes. Individual granuales last for about 20 minutes. The gas within them can reach speeds of 7 km/sec (15,000 mph), faster than the speed of sound in air.