People watch the longest total lunar eclipse of the century at Jarun Lake in Zagreb, capital of Croatia, on July 27, 2018. (Xinhua/Igor Kralj)

People watch the longest total lunar eclipse of the century at Jarun Lake in Zagreb, capital of Croatia, on July 27, 2018. (Xinhua/Igor Kralj)

Photo taken on July 27, 2018 shows the longest total lunar eclipse of the century in Zagreb, Croatia. (Xinhua/Igor Kralj)

People watch the longest total lunar eclipse of the century at Jarun Lake in Zagreb, capital of Croatia, on July 27, 2018. (Xinhua/Igor Kralj)

People watch the longest total lunar eclipse of the century at Jarun Lake in Zagreb, capital of Croatia, on July 27, 2018. (Xinhua/Igor Kralj)

The longest total lunar eclipse of the century is seen in the sky over Cairo, Egypt, on July 27, 2018. (Xinhua/Ahmed Gomaa)

The longest total lunar eclipse of the century is seen in the sky over Cairo, Egypt, on July 27, 2018. (Xinhua/Ahmed Gomaa)

The combo photo taken on July 27, 2018 shows the process of the longest total lunar eclipse of the century in the sky over Cairo, Egypt. (Xinhua/Wu Huiwo)

The longest total lunar eclipse of the century is seen in the sky over Cairo, Egypt, on July 27, 2018. (Xinhua/Ahmed Gomaa)

A composite image shows the full moon at perigee, or supermoon, during a total lunar eclipse on Sunday, July. 27, 2018, in Chongqing, China. (Photo: VCG)

Photo taken on July 27, 2018 shows the longest total lunar eclipse of the century in Chongqing, China. (Photo: VCG)

Photo taken on July 27, 2018 shows the longest total lunar eclipse of the century in Shanghai, China. (Photo: VCG)

A composite of six images shows the full moon at perigee, or supermoon, during a total lunar eclipse on Sunday, July. 27, 2018, in Anhui, China. (Photo: VCG)