Concept
Asteroid belt
Related concepts (45)
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.
Absolute magnitude
Absolute magnitude (M) is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly , without extinction (or dimming) of its light due to absorption by interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared among each other on a magnitude scale.
Comet nucleus
The nucleus is the solid, central part of a comet, once termed a dirty snowball or an icy dirtball. A cometary nucleus is composed of rock, dust, and frozen gases. When heated by the Sun, the gases sublime and produce an atmosphere surrounding the nucleus known as the coma. The force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous tail to form, which points away from the Sun. A typical comet nucleus has an albedo of 0.04. This is blacker than coal, and may be caused by a covering of dust.
Rubble pile
In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the various chunks that make them up. The asteroids Bennu and Ryugu have a measured bulk density which suggests a rubble pile internal structure. Many comets and most smaller minor planets (
Frost line (astrophysics)
In astronomy or planetary science, the frost line, also known as the snow line or ice line, is the minimum distance from the central protostar of a solar nebula where the temperature is low enough for volatile compounds such as water, ammonia, methane, carbon dioxide and carbon monoxide to condense into solid grains, which will allow their accretion into planetesimals. Beyond the line, otherwise gaseous compounds (which are much more abundant) can be quite easily condensed to allow formation of gas and ice giants; while within it, only heavier compounds can be accreted to form the typically much smaller rocky planets.
Active asteroid
Active asteroids are small Solar System bodies that have asteroid-like orbits but show comet-like visual characteristics. That is, they show comae, tails, or other visual evidence of mass-loss (like a comet), but their orbit remains within Jupiter's orbit (like an asteroid). These bodies were originally designated main-belt comets (MBCs) in 2006 by astronomers David Jewitt and Henry Hsieh, but this name implies they are necessarily icy in composition like a comet and that they only exist within the main-belt, whereas the growing population of active asteroids shows that this is not always the case.
Debris disk
A debris disk (American English), or debris disc (Commonwealth English), is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris disks are found around stars with mature planetary systems, including at least one debris disk in orbit around an evolved neutron star. Debris disks can also be produced and maintained as the remnants of collisions between planetesimals, otherwise known as asteroids and comets.
Micrometeorite
A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteorites as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).
Proper orbital elements
NOTOC The proper orbital elements or proper elements of an orbit are constants of motion of an object in space that remain practically unchanged over an astronomically long timescale. The term is usually used to describe the three quantities: proper semimajor axis (ap), proper eccentricity (ep), and proper inclination (ip). The proper elements can be contrasted with the osculating Keplerian orbital elements observed at a particular time or epoch, such as the semi-major axis, eccentricity, and inclination.
Yarkovsky effect
The Yarkovsky effect is a force acting on a rotating body in space caused by the anisotropic emission of thermal photons, which carry momentum. It is usually considered in relation to meteoroids or small asteroids (about 10 cm to 10 km in diameter), as its influence is most significant for these bodies. The effect was discovered by the Polish-Russian civil engineer Ivan Osipovich Yarkovsky (1844–1902), who worked in Russia on scientific problems in his spare time.