where are asteroids located within our solar system
Asteroid belt The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets. The asteroid belt is also termed the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids.[1] About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea.[1] The total mass of the asteroid belt is approximately 4% that of the Moon, or 22% that of Pluto, and roughly twice that of Pluto's moon Charon (whose diameter is 1200Â km).
Earth Earth's biosphere has significantly altered its atmosphere. Oxygenic photosynthesis evolved 7000270000000000000♠2.7 Gya, forming the primarily nitrogen–oxygen atmosphere of today.[71] This change enabled the proliferation of aerobic organisms and, indirectly, the formation of the ozone layer due to the subsequent conversion of atmospheric O2 into O3. The ozone layer blocks ultraviolet solar radiation, permitting life on land.[145] Other atmospheric functions important to life include transporting water vapor, providing useful gases, causing small meteors to burn up before they strike the surface, and moderating temperature.[146] This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature. Water vapor, carbon dioxide, methane, nitrous oxide, and ozone are the primary greenhouse gases in the atmosphere. Without this heat-retention effect, the average surface temperature would be −18 °C, in contrast to the current +15 °C,[147] and life on Earth probably would not exist in its current form.[148] In May 2017, glints of light, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere.[149][150]
Solar System The Solar System[a] is the gravitationally bound system comprising the Sun and the objects that orbit it, either directly or indirectly.[b] Of the objects that orbit the Sun directly, the largest eight are the planets,[c] with the remainder being smaller objects, such as dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly, the moons, two are larger than the smallest planet, Mercury.[d]
Thalamus It is a midline symmetrical structure of two halves, within the vertebrate brain, situated between the cerebral cortex and the midbrain.