We have observed a comet strike Jupiter.

The full Moon’s apparent magnitude is

The main sequence is luminosity class V.

The largest difference between Mars’ northern and southern hemispheres is that

On the H-R diagram, the Sun lies

Rigel has an apparent magnitude of + 0.18 and Betelgeuse an apparent magnitude of +0.45. What can you conclude from this?

The largest difference between Mars’ northern and southern hemispheres is that

The Sun’s magnetic field is very weak compared to Earth’s.

A loop of gas following the magnetic field lines between sunspots’ poles is

What is the Schwarzschild radius of a black hole?