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
From the Earth to the Moon the Moon. It seems appropriate to us to share with you some of the reflections of the crew as the modern-day Columbia completes its rendezvous with the planet Earth and the same Pacific Ocean tomorrow." In "Back to the Future Part III", Clara Clayton in 1885 asks Emmett Brown if he believes mankind will ever "travel to the moon the way we travel across the country on trains." Being from the future Doc already knows that doesn't happen for another 84 years, but he affirms they will while quoting a passage of "From the Earth to the Moon". Clara calls