Current searches for extraterrestrial intelligence use radio ...

[ericka1]

Current searches for extraterrestrial intelligence use radio telescopes at wavelengths
 
  a. which must be shorter than the local wavelengths emitted by Earth's atmosphere.
  b. which must be longer than the radio wavelength noise' naturally emitted by our galaxy.
  c. which must be longer than the local wavelengths emitted by Earth's atmosphere and which must be shorter than the radio wavelength noise' naturally emitted by our galaxy.
  d. Wrong Visual light wavelengths are used because radio waves are blocked by dust between the stars.

Question 2

The number of technological civilizations in our galaxy is limited by
 
  a. the number of stars in our galaxy.
  b. the fraction of stars with planets.
  c. the number of planets per star in habitable zones longer than a few billion years.
  d. the fraction of suitable planets where technical life forms evolve.
  e. the number of stars in our galaxy, the fraction of stars with planets, the number of planets per star in habitable zones longer than a few billion years, and the fraction of suitable planets where technical life forms evolve.

[kaillie]

Answer to Question 1

c

Answer to Question 2

e

[ericka1]

TYSM

[yeungji]

Gracias!