Why did people think that the Earth was the centre of the universe?
-The Sun, Moon and Stars seemed to orbit around the Earth.
What is a sidereal day?
-The time taken for a star to return to the same position in the sky.
How long is a sidereal day?
-23 hours and 56 minutes
For a star to get to the same position in the sky, what degree does the Earth have to spin?
The Sun and Moon appear to cross the sky at different ******.
The Sun and Moon appear to cross the sky from **** to ****.
-East to west
The Sun seems to move **** slowly across the sky than distant stars.
What is a solar day?
-The time taken for the Sun to appear at the same position in the sky.
How long is a solar day?
How much longer is a solar day compared to a sidereal day?
-4 minutes longer
Why are solar and sidereal days different?
-The Earth orbits the Sun as well as spinning on its axis.
Why does the Earth need to spin slightly more than 360° before the Sun appears at the same position in the sky?
-The Earth orbits the Sun in the same direction as it spins.
How long does it take for the Moon to appear at the same position in the sky?
Why does it take the Moon longer to appear at the same position in the sky than the Sun?
-The Moon orbits the Earth in the same direction as the Earth is rotating.
As the Earth moves around the Sun, the direction we face changes slightly each ***.
What is an Earth year?
-The time it takes the Earth to orbit the Sun once.
“We can see a different patch of sky each night – we see different stars” – True or False?
How does the moon glow?
-Reflects light from the Sun.
What fraction of the moon is lit up, and what fraction is shadow?
What sort of moon do you see when the whole of the –lit-up surface is facing the Earth?
What sort of moon do you see when the dark half faces us?
When do eclipses happen?
-When light from the sun is blocked
What is a lunar eclipse?
-No direct sunlight can reach the Moon.
What is a solar eclipse?
-When the Moon blocks out the sunlight.
Why don’t eclipses happen often?
-The Moon is at a slight angle to the Earth’s orbit around the Sun. So the Sun, Moon and Earth do not line up to cause a lunar or solar eclipse.
Why do partial eclipses happen more often than total eclipses?
-The Sun, Moon and Earth do not have to line up perfectly in partial eclipses.
How are the positions of star measured?
-Angles seen from the Earth.
What are the 2 fixed positions that astronomers measure from?
-The Pole Star, the…