This spacecraft would carry a Lunokhod — a large, long-distance moon rover.
To find the spatial extent that 2.5e-7 radisns is at the distance of the moon, set up a triangle between Earth and the Moon, where R is the angle in radians that we calculated, x is the side opposite angle R which corrosponds to the object on the moon, and the adjacent side is the Earth-Moon distance.
Whereas the tidal forces have slowed down the earth's spin significantly over the aeons, measurements of Earth-Moon distance by Apollo missions has revealed that Moon is drifting away from Earth by 3 to 4 cms every year.
Amalthea provided the final satellite fly-by for Galileo on November 5 , 2002 at a distance from the moon's center of approximately 244 km (height about 160 170 km), permitting the moon's mass to be accurately determined, while changing Galileo's trajectory so that it would plunge into Jupiter in September 2003, having finished its mission.
The distance to the moon is 384,400 km.
The known distance of the Moon provided the scale.
The rock, code-named 2004 BL86, will pass by at about three times the distance of the moon.
The average distance of the moon, which keeps an imperfect 27-day oval orbit, is 238,855 miles.
The distance to the moon varies, depending on where it is in its orbit, but the average distance is about 380,000km.
Laser ranging with the retro reflectors is still providing measurements of the distance of the moon for precision tests of gravity physics.
