Space Review Test Tomorrow

Astronomy The study of the universe

Earths motion Rotation – spinning on its axis, causes day and night, takes 1 day to rotate completely Revolution – the Earth orbits the sun, takes one year to travel completely around the sun.

Vocabulary Precession – change in the orientation of the axis of a rotating body Nutation – swaying motion of precession Barycenter – center of mass/gravity

The speed increases the closer Earth is to the sun and decreases the farther it is from the sun. The earth revolves around the sun The moon revolves around Earth

Seasons

Caused by the – Angle of suns rays – Length of days When the northern hemisphere is tilted towards the sun it has summer and the southern hemisphere is tilted away from the sun so it has winter. Days are longer in the summer and shorter in the winter

Tides Tides are caused by the gravatational pull from the moon and the sun Spring tide – sun moon and earth are all aligned, higher high tides and lower low tides Neap tide – sun moon and earth are at right angle, lower high tide and higher low tide

Moon Phases Moon phases are caused by the moons orbit. Half the moon is always lit by the sun, as it orbits we see different parts of the lighted area. The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky. It takes 29.5 days to complete a cycle

Solar Eclipse Moon covers the sun during the day

Lunar Eclipse Moon passes into the Earths shadow

The Sun The sun is our nearest star It creates its energy by nuclear fusion – Nuclear fusion is when two hydrogen atoms fuse together to create one helium atom – The process that produces the radiant energy of stars Travels through space by sending electromagnetic waves by radiation

Solar System Nebular hypothesis – states that the solar system began as a large cloud of gas and dust that was brought together by gravity and began to form planets over a very long period of time.

The Universe Slowly expanding Made up of billions of galaxies – Which contain billions of stars