Point of a heliocentric orbit farthest from the Sun. Rocky, carbonaceous or metallic body, smaller than a planet.
Most asteroids have orbits between Mars and Jupiter.
Small meteoroid for which radiation pressure force is comparable to solar gravitational attraction. Ratio of electromagnetic energy reflected by a surface to the amount of incident energy. Undifferentiated stony meteorite that contains chondrules. Millimeter-sized, spheroidal particles in meteorites that were once molten droplets. Cometary head generated by a roughly spherical outflow of gas and dust from a comet nucleus .