Describe the circumstances that cause a lunar eclipse to occur. What causes the moon to appear an orangish red during a total lunar eclipse?

A lunar eclipse happens when the Moon passes directly behind the Earth and into its shadow. This can only happen when the Sun, Earth, and Moon are aligned. Because of this, a lunar eclipse can only happen on the night of a full moon.

The moon gives off a reddish appearance during this time because the only light reaching the moon and reflected off of its surface is the light refracted by the Earth's atmosphere (the same reason a sunrise/sunset appears reddish).

A totally eclipsed full moon is also known as a Blood Moon because of it's colour