P7-1

A sidereal day is the time taken for a star to return to the same position in the sky. It's about 23 hours and 56 minutes.

A solar day is the time taken for the sun to appear at the same position in the sky. It's 24 hours. It is 4 minutes longer because the sun seems to move more slowly than distant stars.

The sun and moon appear to cross teh sky at different speeds from east to west.

The stars that you can see in the sky change during the year.

As the earth moves around the sun, the direction we face changes each day, this means we can see a slightly different patch each night. An earth year is the time it takes teh Earth to orbit teh sun.

The phases of the moon- We see the moon because ot reflects light from the sun, only the half facing the sun is lit up, leaving the other half in the shadow.

As the moon, orbits the sun different amounts of the moons dark and lit up surfaces.

Solar Eclipse - When the Earth blocks out the light from the sun, leaving the moon in the Earth's shadow.

Lunar Eclipse- When the moon blocks out the light form the sun and comes between the sun and the earth.

Eclipses don't happen very often becauseit is very rare that the earth sun and moon line up perfectly because the earth has a 5 degree tilt.