Blood Moon 2018: Longest total Lunar Eclipse of the 21st century occurs July 27, 2018

The longest total lunar eclipse of the 21st century is only a couple days away.

The total phase of the "blood moon" eclipse of July 27 will last 1 hour and 43 minutes, during which Earth's natural satellite will turn a spectacular red or ruddy-brown color. From start to finish, the entire celestial event will last nearly 4 hours.

The eclipse won't be visible to viewers in North America, except via webcasts. But observers in much of Africa, the Middle East, southern Asia and the Indian Ocean region will get an eyeful, given cooperative weather, according to lunar scientist Noah Petro, of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

July's total lunar eclipse occurs on the same day the planet Mars reaches its opposition, when it will shine at its best in the night sky. This month, Mars will be at its closest to Earth since 2003. After opposition, when Mars will be brightest, it will reach that closest point on July 31.