What is a planetary system?
What is in the solar system?
Focus on: how the solar system formed
What is an extrasolar planet?
What was the first extrasolar planet found?
How many extrasolar planets have been discovered?
How many other planetary systems are there?
How far away are other planetary systems?
Do most other planetary systems have stars like the sun?
Focus on: what other planetary systems might be like
Is it hard to find extrasolar planets?
How do astronomers look for extrasolar planets?
Focus on: the transiting method for finding extrasolar planets
Which planet-finding method have astronomers used the most?
Have scientists ever seen an extrasolar planet?
Are any extrasolar planets like Earth?
Focus on: what extrasolar planets might look like
What makes Earth right for life?
Is there life on extrasolar planets?
Why is the size of an extrasolar planet important?
How will scientists know if there is life on an extrasolar planet?
Are there new ways to search for extrasolar planets?
