The Bridge V Learning Edition 1 ; our solar system | Page 45

The Moon has quakes.
These are caused by the gravitational pull of the Earth. Lunar astronauts used seismographs on their
visits to the Moon, and found that small moonquakes occurred several kilometres beneath the
surface, causing ruptures and cracks. Scientists think the Moon has a molten core, just like Earth.
The first spacecraft to reach the Moon was Luna 1 in 1959.
This was a Soviet craft, which was launched from the USSR. It passed within 5995 km of the surface
of the Moon before going into orbit around the Sun.
The Moon is the fifth largest natural satellite in the Solar System.
At 3,475 km in diameter, the Moon is much smaller than the major moons of Jupiter and Saturn.
Earth is about 80 times the volume than the Moon, but both are about the same age. A prevailing
theory is that the Moon was once part of the Earth, and was formed from a chunk that broke away
due to a huge object colliding with Earth when it was relatively young.
The Moon will be visited by man in the near future.
NASA plans to return astronauts to the moon to set up a permanent space station. Mankind may
once again walk on the moon in 2019, if all goes according to plan.
During the 1950’s the USA considered detonating a nuclear bomb on the Moon.
The secret project was during the height cold war was known as “A Study of Lunar Research Flights”
or “Project A119” and meant as a show of strength at a time they were lagging behind in the space
race.