About Moon - Earth' Satellite How moon was formed

# Its diameter is only one-quarter that of the earth.

# It is about 3,84,400 km away from us.
A ray of light from the sun takes about eight minutes to reach the earth. Light takes only a second to reach us from the moon.

# The moon is tidally locked to the earth, meaning that the moon revolves around the earth in about 27 days which is the same time it takes to complete one spin.

# Tidal locking is the name given to the situation when an object’s orbital period matches its rotational period.

# As a result of tidal locking, only one side of the moon is visible to us on the earth.

# The moon is a significant stabiliser of Earth’s orbital axis. Without it, Earth’s tilt could vary as much as 85 degrees (at present the Earth’s axis of rotation is tilted at an angle of 23.5֯ relative to our orbital plane).

# Neil Armstrong was the first, and Buzz Aldrin was the second to step on the surface of the moon on 29 July 1969 (Apollo 11 mission).

# Till date, only Twelve astronauts walked on the Moon’s surface.

Formation of the moon

# It is now generally believed that the formation of the moon, as a satellite of the earth, is an outcome of ‘giant impact’ or what is described as ‘the big splat’.

# A body of the size of one to three times that of mars collided into the earth sometime shortly after the earth was formed. It blasted a large part of the earth into space.

# This portion of blasted material then continued to orbit the earth and eventually formed into the present moon about 4.44 billion years ago.

# Scientists estimate that a day in the life of early Earth was only about 6 hours long.

# The Moon formed much closer to Earth than it is today.

# As Earth rotates, the Moon’s gravity causes the oceans to seem to rise and fall. There is a little bit of friction between the tides and the turning Earth, causing the earth’s rotation to slow down just a little (1.4 milliseconds in 100 years).

# As Earth slows, it lets the Moon move away by a little (four centimetres per year).