Aristotle believed that the heavenly bodies moved only in circular orbits at a uniform speed.
In 1962, two Soviet spacecraft circled earth in adjacent orbits, and were in visual and radio contact.
Some astronomers believe Pluto's strange orbit indicates that it wasn't one of the
original planets at all, but rather a moon of Neptune that somehow broke loose.
In 1969, the Soviet Soyuz 4 and Soyuz 5 linked up to become the first manned spacecraft to dock in Earth's orbit.
Johannes Kepler, a German astronomer and mathematician, made the discovery that the planets move in
oval-shaped orbits.
Halley's comet is named after Edmond G. Halley, who was the first to suggest that comets were natural phenomena of our solar system, in orbit around the sun.
There are more than 200 satellites orbiting earth solely for the purpose of private communications
services, including pagers, telephones, and computers.
The sun, moon, planets and stars all move along their various orbits.
The moon does not actually orbit the earth; the earth and moon orbit each other.
The moon orbits around our earth at an average distance of 384,401 kilometers.
The Americans have sent the space shuttle into orbit in an effort to retrieve a damaged satellite.
The classification of comets is determined by the type of orbit in which they move.
The space shuttle goes into orbit like a rocket, and returns to earth like an aircraft.
As of 2003, there are 58 known natural satellites orbiting the planet Jupiter.
When astronauts first shaved in orbit, their whiskers floated up to the ceiling because they were weightless in space.
The Earth's orbit around the sun is not perfectly circular; it is slightly oval-shaped.
The United States launched a spy satellite into orbit in December of 1988.
The second part of the rocket carries the fuel which provides the thrust needed to get the rocket out of the Earth's orbit.
Our earth orbits the sun at a speed of about 18.5 miles a second.