The consistency of the objects is predominant
- gaseous - stars of various kinds, star shells, gas planets, gas nebulae, interstellar matter and molecular clouds, halos, ...
- liquid - the interior of large gas planets
- solid - rocky planets, moons, asteroids, comets, meteoroids, ...
- dusty - dark clouds, planetary rings, interplanetary dust
- composite systems - star clusters, galaxies, galaxy clusters
- Empty spaces - voids between the galaxy clusters
- unexplained - e.g. B. Black holes, dark matter.
|Observation in the solar system||Observation outside the solar system|
These are objects of cosmology , such as the basic structures of the universe ( filaments and voids ) and - so far - hypothetical or not yet sufficiently clarified in their nature objects, such as black holes or dark matter .
Classification according to distance
An orientation of individual areas of astronomy:
Objects close to the earth :
- Atmospheric objects : up to the exosphere (500 and 1000 km)
- Earth orbital objects : approximately up to the distance of a geostationary orbit (approx. 36,000 km)
- Objects close to the earth : up to the lunar orbit (around 400,000 km) or - according to another point of view - up to the inner Lagrangian point (i.e. primarily subject to gravity: approx. 1.5 million km from the earth)
Solar objects :
- Objects of the inner solar system : up to the asteroid belt (about 450 million km = 3 AU )
- The asteroid belt as the boundary between the inner and outer solar system, the dwarf planet Ceres
- Outer solar system : 7.5 billion km = 50 AU
Peripheral areas of the solar system : objects far from the sun up to the heliopause , about 100,000 AU = 1.5 light years
- The Oort cloud
- Long-period comets and aperiodic comets with hyperbolic or parabolic orbits that cross the solar system extensively.
Extrasolar objects : objects outside the boundaries of the solar system ( deep sky objects).
- Galactic Neighborhood Objects :
- Galactic objects : an area of 100,000 ly (30 kpc )
- Extragalactic Objects: