A lunar eclipse, popularly known as a 'blood moon', was briefly visible from parts of New Zealand early on Saturday morning. Folau delivered his tweet at 8:01am, just as the celestial event was getting underway.

Detractors on social media asked him to focus on tonight's Waratahs-Lions semi-final instead.

"It's only an eclipse Izzy. Focus on the game," said @PeterRose2001.

"We've been in end times for the best part of two thousand years. So no hurry. Just chill," said @TwoThirdsDeuce.

Lunar eclipses happen between two and five times a year. Saturday's was the second visible from New Zealand this year.

Astronomers are able to predict them hundreds of years in advance, provided nothing happens to upset the balance of the solar system, such as a Mars-sized asteroid hitting the Earth.

Folau didn't directly refer to the eclipse.

Newshub.