Unit 10: Exoplanets & Astrobiology

Question 1

Explain the radial velocity detection method.

Answer 1

The doppler effect can detect the slight wobbles of a star if the star happens to orbit more or less in a plane along our line of sight, but the velocities are small; we only see the spectrum of the star

Question 2

Explain the transit detection method.

Answer 2

When a planet passes between a star and its observer (known as transit), we see a dip in the host star’s flux which occurs every orbit of the planet. The duration and amount of decrease tells us about the orbital period and radius of the exoplanet.

Question 3

What is the habitable zone?

Answer 3

An estimate of the range around a star where liquid water could exist

Question 4

What is the Drake equation used for?

Answer 4

It’s used to estimate the number of active, extraterrestrial civilizations in the Milky Way Galaxy.