Luna programme became the first probe to achieve a soft landing on another planetary body. It returned five black and white stereoscopic circular panoramas, which were the first close-up shots of the Lunar surface. "Luna 10" (March 1966) became the first artificial satellite of the Moon. "Luna 17" (November 1970) and "Luna 21" (January 1973) carried the Lunokhod vehicles, which roamed around on the Moon's terrain. Another major achievement of the Luna programme, with "Luna 16" (September 1970), "Luna 20" (February 1972) and "Luna 24" (August 1976), was the ability to collect samples of lunar soil and return them to Earth. The
Celestial sphere the equatorial coordinate system, the celestial equator divides the celestial sphere into two halves: the northern and southern celestial hemispheres. Because astronomical objects are at such remote distances, casual observation of the sky offers no information on their actual distances. All celestial objects seem equally far away, as if fixed onto the inside of a sphere with a large but unknown radius, which appears to rotate westward overhead; meanwhile, Earth underfoot seems to remain still. For purposes of spherical astronomy, which is concerned only with the directions to celestial objects, it makes no difference if this is actually the case