The Cassegrain reflector needs a primary concave main mirror and ...

[sarasara]

The Cassegrain reflector needs a primary concave main mirror and a smaller, convex secondary mirror to reflect light back through a hole in the primary.
 
  Indicate whether the statement is true or false

Question 2

Why is the impact theory now preferred as an explanation for the Moon's origin?
 
  What will be an ideal response?

[poopface]

Answer to Question 1

TRUE

Answer to Question 2

The capture theory is unlikely for a body as big as the Moon, while the coformation theory would have the Moon orbit our equator as it condensed. The impacting body would be of different composition than the Earth, and the heat of impact would drive off the lighter materials, as noted for the Moon's crust. The body would also have been moving in the ecliptic plane before impact, and the Moon still orbits close to the ecliptic even now.

[sarasara]

Excellent

[peter]

Gracias!