What makes the moon appear blood red during a lunar eclipse?
THE RIGHT ALIGNMENT: A lunar eclipse occurs when the sun, Earth and moon are in a straight line. As the sun lights up one side of the Earth it casts a shadow into space. When the moon starts passing into that shadow it becomes darker, eventually turning redder from sunlight passing through Earth's atmosphere.
WHY NOT EVERY FULL MOON: Lunar eclipses happen during a full moon, but do not occur every full moon. This is because the orbit of the moon varies, tilted about five degrees as it moves around Earth, and therefore it is not always in the Earth's shadow.
DIFFERENCE BETWEEN SOLAR AND LUNAR ECLIPSE: A solar eclipse occurs when the moon passes between the Earth and the sun, casting a shadow over the Earth. A lunar eclipse takes place when the moon moves into the Earth's shadow.
VISIBILITY: Protective filters are advised for people gazing at a solar eclipse, while a lunar eclipse is completely safe to view with the naked eye, and far more visible than a solar eclipse.
ARE THEY RARE?: On average a lunar eclipse can be seen in Australia every 2.8 years. Two lunar eclipses occurred in 2018 - January 31 and July 28. The next lunar eclipse is predicted for 2021.
