Our Place - Our Place In space Earth 1 planet of 8 Sun an...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
In space… Earth – 1 planet of 8 Sun – an ordinary star. One of 100 billion in our galaxy the “Milky way” Milky Way – typical galaxy, one of 10s or 100s of billions of galaxy in observable universe The scale of thins Solar system :all 8 planets lie within about 40 astronomical units. 1 AU is about 150 million km Distance between stars often measured in light years Speed of light = 300,000 km/s = 9.46 trillion km/yr 1 light year = 9.46 trillion km (5.88 trillion miles) Our galaxy is about 100.00 ly across How can we know what the universe was like in the past? Light travels at a finite speed Moon light travel time 1 second Sun light travel time 8 minutes Sirius light travel time 8 years Andromeda Galaxy light travel time 2.5 million years Thus we see objects as they were in the past. The farther away we look in distance the further back we look in time. How is Earth moving in our solar system Contrary to our perception we are not sitting still. We are moving with the Earth in several ways and at surprisingly fast speeds.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/10/2010 for the course ED 4070 taught by Professor Sweet during the Fall '09 term at Western Michigan.

Page1 / 3

Our Place - Our Place In space Earth 1 planet of 8 Sun an...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online