You can change your cookie settings at any time. White dwarfs are typically composed primarily of carbon, have about the radius of the earth, and do not significantly evolve further. Density is measured in grams per cubic centimeter or kilograms per liter. Rhyolite fine-grained extrusive igneous rock, commonly with phenocrysts of quartz and feldspar in a glassy groundmass. Photon a discrete quantity of electromagnetic energy. This happens on about March 20 each year.
Light waves created by fluctuations of electric and in space. Stratosphere the cold region of a planetary atmosphere above the convecting regions the troposphere , usually without vertical motions but sometimes exhibiting strong horizontal jet streams. In this scale, each number is 2. An international organization that unites national astronomical societies from around the world and acts as the internationally recognized authority for assigning designations to celestial bodies and their surface features. An astronomical unit of measure equal to the distance light travels in a year, approximately 5.
A tube-like configuration of energy that is believed to have existed in the early universe. Axial inclination axial inclination is the angle at which a planet's axis of rotation is tilted, with respect to that planet's own orbit. Constellation a grouping of stars that make an imaginary picture in the sky. Differentiated when a partially molten body has been divided into two or more fractions of dissimilar compositions. There definitions for the Big Bang theory, comets, eclipses, Magellanic Clouds, Mars, quasar, relativity, and variable stars.
The area around a most affected by its. Eight percent of the atoms in the universe are helium. Pallasite a stony-iron meteorite in which nodules of olivine a silicate mineral are surrounded by a network of iron-nickel metal. Link to this page: Greatest mathematical distance of all was that between Captain Duncan's mind and the mind of an astronomer who charted the heavens and navigated a thousand million miles away among the stars and who tossed, a mere morsel of his mathematical knowledge, the few shreds of information to Captain Duncan that enabled him to know from day to day the place of the Makambo on the sea. A that has a ring-like appearance. He demonstrated that meteors are cosmic in origin and not an atmospheric phenomenon. It is caused by charged particles from the Sun as they interact with the Earth's magnetic field.
Rich clusters — Galaxy clusters with high population densities. Van Allen Belts radiation zones of charged particles that surround the Earth. Posted on March 19, 2012. MeV one million electron volts. Vent the opening in the crust through which volcanic material erupts. A celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighboring region of. Proper Motion the apparent angular motion across the sky of an object relative to the Solar System.
The energy acquired by an electron when it accelerates through a potential difference of 1 volt in a vacuum. The first paragraph of each entry block is devoted to the definition s of the entry. Gamma Ray the highest energy shortest wavelength photons in the electromagnetic spectrum. It is visible to the naked eye during a solar eclipse. The period of time it takes the Moon to make one complete revolution around the Earth. Lenticular Galaxy a disk-shaped galaxy that contains no conspicuous structure within the disk.
Lenticular galaxies tend to look more like elliptical galaxies than spiral galaxies. Astrochemistry the branch of science that explores the chemical interactions between dust and gas interspersed between the stars. On this scale, the Sun has an absolute magnitude of +4. The main entries, in English, are accompanied by their French and Persian equivalents in the present version. The molecular structure looks like the geodesic domes designed by Buckminster Fuller.
Unchanged meteorites due to melting. Young Review from previous edition This is an excellent dictionary. Irregular Galaxy a galaxy with no spiral structure and no symmetric shape. The field of astronomy that studies celestial objects by the they emit. The Earth is a planet. Penumbra — Outer filament region of a sunspot.
Evolved Star a star that is near the end of its life cycle where most of its fuel has been used up. These pressures may be sufficiently high to shatter, melt, and vaporize rocky material. You do not look at the object directly, but just off to the side, you do this while concentrating on the object. Achromatic lenses are used to take chromatic aberrations away from images. Quasars release incredible amounts of energy and are among the oldest and farthest objects in the known universe. They may be the nuclei of ancient, active galaxies. Ian Ridpath has done a remarkable job to achieve such consistency in the style, technical level and length of entries.
Synchrotron emission — Electromagnetic field from high-energy electrons that are moving in a given magnetic field. Impact melt spherule spherules of shock-melted rock ejected from an impact crater. Redshift indicates that an object is moving away from the observer. Ephemeris tables are typically to list the positions of the Sun, Moon, planets and other solar system objects. Radiation Belt a ring-shaped region around a planet in which electrically charged particles usually electrons and protons are trapped.