Physics - P1 Flashcards
what is the sun?
a star
how many planets are there?
8
what do planets reflect?
light
what do comets have tails?
the ice inside them melts as they get closer to the sun
what is the sun made from?
hydrogen and helium gas
how is the helium made?
hydrogen atoms fusing together this is where the sun gets its energy
what do we use to measure the distance in space?
light years
how fast does light travel?
300,000 km/s
what are the sizes on the thing in the universe in the order smallest to biggest (diameter)?
earth sun earths orbit solar system sun to the nearest star milky way milky way to the nearest galaxy
what are the ages of the earth, sun and universe in order smallest to biggest?
earth- 5000
sun- 5000
universe- 14000
what do stars emit (give out)?
electromagnetic (EM) radiation
what is parallax?
when something appears to move when you look at it from different places
what is light pollution?
light from streetlamps etc.
how do we see things in space?
we see them as they were when the light first left them
what are other galaxy’s doing?
moving away from us (red shift)