Author Question: The Milky Way Galaxy's galaxy type is SBb. Indicate whether the statement is true or ... (Read 50 times)

notis · **on:** Jul 27, 2018

The Milky Way Galaxy's galaxy type is SBb.

Indicate whether the statement is true or false

Question 2

If we detected an Earth-like planet in the habitable zone around another star, describe how we might learn whether it contained life.

What will be an ideal response?

lauravaras · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

TRUE

Answer to Question 2

Future technology (large space-based interferometers) will be able to measure the far-infrared spectrum of the planet's atmosphere. Ozone produces a strong feature in the Earth's atmosphere and would be detectable in the hypothetical extrasolar planet with the planned space interferometer. Ozone is related to oxygen, which is highly reactive, and would rapidly disappear (through oxidation) from the atmosphere were it not being constantly replenished. Converting oxides back to oxygen requires energy and is not a chemical reaction that would spontaneously occur otherwise. In the Earth's case, the energy comes from the sun via photosynthesis in plants and the detection of ozone near another planet would therefore be a strong indicator of life.