Blog

When Earth overtakes Mars, the outer planet retrogrades near __________ .

According to Newton’s third law, when the Voyager probes passed Jupiter in 1979, they exerted exactly the same force on Jupiter as the giant planet did on them.

An emission line results from an electron falling from a higher to lower energy orbital around its atomic nucleus.

Which of these is not a form of electromagnetic radiation?

The Doppler effect can reveal the rotation speed of a star by the splitting of the spectral lines.

An electron has a(n)  _________ electric charge.

The larger the red shift, the faster the distant galaxy is moving away from us.

According to Copernicus, retrograde motion for Venus must occur around

The radiation our eyes are most sensitive to lies in the color:

The asteroids moving in the orbit of Jupiter, but 60 degrees ahead or behind it, are called the __________ .