At which phase of the Moon do Solar eclipses occur?

If the source of the wave is moving towards the observer, the wavelength of the emitted wave

One characteristic of Venus, which distinguishes it from the other planets, is

Which of the following statements is correct about the surface temperature of the following stars? 

We have evidence that the Earth’s magnetic field has reversed its direction over long periods of time

Which of the following is a consequence of the fact that the rotation and revolution periods of the moon are the same (synchronous rotation)?

The surface temperature on Venus is

The surface temperature of a star increases from 4000 K to 8000 K. If so, what happens to the magnitude of the energy per unit of time and per unit of area that is emitted from the star.

Solar and Lunar eclipses do not occur as often as every month, because

What are the two most abundant gases in the Earth’s atmosphere?