Near-Earth object Near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it to proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's and the object is larger than across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets. There are over 19,000 known near-Earth asteroids (NEAs), over a hundred short-period near-Earth comets (NECs), and a number of solar-orbiting spacecraft
Around the Moon to Earth. During the latter part of the voyage, it becomes apparent that the gravitational force of their earlier encounter with the asteroid has caused the projectile to deviate from its course. The projectile enters lunar orbit, rather than landing on the moon as originally planned. Barbicane, Ardan and Nicholl begin geographical observations with opera glasses. The projectile then dips over the northern hemisphere of the moon, into the darkness of its shadow. It is plunged into extreme cold, before emerging into the light and heat again. They then begin to approach the moon's southern hemisphere. From the safety of