Astronomy Flashcards
How does gravity affect the Moon and artificial satellites?
It makes them orbit the Earth, as opposed to moving in a straight line
Who first explained how gravity keeps objects in orbit?
Isaac Newton
What example did Isaac Newton use to explain gravity?
An example of a cannon on the top of a mountain
Describe the Earth’s orbital path
A slightly eccentric ellipse -a slightly squashed circle
Describe a comet’s orbital path
A highly elliptical orbit
How do you measure the circumference of a circular orbit?
2 x π x r
How do you measure orbital speed?
V = 2πr / T
How does gravity affect individual stars?
It makes stars orbit the black hole at the centre of the galaxy
What can galaxies do?
They can collide with each other
When is the Milky Way estimated to collide with Andromeda?
in 3-5 billion years
