The total estimated mass of artificial objects on celestial bodies excluding Earth is 476,044 pounds (215,930 kilograms).
The vast majority of objects that remain on the surface of extraterrestrial objects is wreckage from spacecraft that were intentionally crashed such as the Galileo on Jupiter and the MESSENGER probe that ran out of propellant and crashed into Mercury. However, several objects landed substantially intact. NEAR Shoemaker managed to touch down on the asteroid Eros, despite not being designed for that purpose.
Earth’s moon has by far the most artificial objects currently on its surface. There is an estimated 413,100 pounds (187,400 kilograms) of man-made weight.
The first man-made object to land on any celestial body was the Luna 2, launched by the Soviet Union in 1959. It contributed the first 860.2 pounds to the moon’s surface. It carried five different instruments meant to conduct various tests as it journeyed to the moon. Even as the Soviets began announcing information gathered from the Luna 2, the Americans remained skeptical. Bernard Lovell was able to prove that Luna 2 made it to the moon by showing the Doppler shift from its transmissions.
Overall, the United States have contributed the most artificial mass to extraterrestrial surfaces, although the Soviet Union was the first to launch something into space.
The development and use of long-range ballistic missiles by Nazi Germany nearing the end of World War II triggered the space race that would commence between the United States and the Soviet Union. The Soviet Union was the first to launch an artificial satellite into space (Sputnik 1) on October 4th 1957, and a Russian man by the name of Lt. Yuri Gagarin was the first human to orbit the earth in a spacecraft (Vostok 1) on April 12, 1961. On July 20th 1969, astronaut Neil Armstrong became the first human being to step upon the moon.
In 1959, the Soviet Union’s Luna 2 was the first man-made object to land on an extra-terrestrial surface.
Americans were beginning to believe that they were excelling over USSR during the space race because of their superior guidance systems, despite having smaller rockets. This myth was dispelled after the Soviets managed to crash Luna 2 onto the moon on September 13th 1959. At that moment, the closest Americans had come to the moon was about 37,000 miles (60,000k) with Pioneer 4. This infographic profiles all of the “space junk” that has since been deposited on extra-terrestrial bodies.