What evidence did astronomers use to prove jets travel in ...

[vicky]

What evidence did astronomers use to prove jets travel in opposite directions?
 
  a. spectral lines from fast-moving red- and blue-shifted ionized gas
 b. gamma ray emission spectra
 c. magnetic tubes in accretion disks
 d. mass transfer from a binary star to a compact companion
 e. pulsar rotation periods

Question 2

Ancient astronomers often had difficulty explaining _____, the occasional westward motion of the planets.
 
  a. parallax
 b. eccentrics
 c. retrograde motion
  d. deferents
 e. epicycles

[Sammyo]

Answer to Question 1

a

Answer to Question 2

c

[vicky]

Thanks for the timely response, appreciate it

[sailorcrescent]

Excellent