The last lunar eclipse of the year will take place this week, allowing stargazers from large swathes of the globe to catch a glimpse of the celestial phenomena.
The partial lunar eclipse will occur during the full moon beginning Tuesday night, and will be visible in South America, Europe, Africa, Asia and Australia. The only region that will miss out on viewing the eclipse entirely is North America.
A lunar eclipse occurs when there is an alignment of the moon, the sun and the Earth. It can only happen during a full moon, because that is the only time the moon can be directly opposite of the sun in Earth’s sky.
The upcoming alignment will result in a partial lunar eclipse because the moon will be slightly askew from a direct line with Earth’s shadow.
This lunar eclipse will come two weeks after a total eclipse of the sun was visible over South America. This follows a typical astronomical pattern of lunar eclipses occurring within two weeks of a solar eclipse.
The last lunar eclipse took place in January 2019 and was visible from both Americas as well as parts of Europe and Africa. The next lunar eclipse will not take place until next year, however all four eclipses in 2020 will only be penumbral eclipses, which are much weaker than partial or full eclipses.
During penumbral eclipses, the moon passes through the weakest shadow cast by Earth and often does not visibly darken to the naked eye.
There won't be another total lunar eclipse until May 2021.
Tuesday’s lunar eclipse will be seen by stargazers at different times around the globe. Viewers in South America will be the first to see Earth’s shadow touch the moon’s surface when the moon is rising in the sky around sunset July 16, while watchers in Asia and Australia will see the moon in eclipse as it sets around sunrise July 17.
Interestingly, this celestial event falls on the anniversary of another lunar happening: July 16 is the 50th anniversary of the Apollo 11 rocket launch, which first landed humans on the moon.