On the night from Saturday to Sunday, astronomy enthusiasts will be able to observe a blue micromoon, a rare celestial spectacle that will not happen again for another two years, CBS News reported Thursday.

The event combines two astronomical rarities. On one hand, it is a blue moon, the name given to the second full moon occurring within the same month, which happens every two to three years. The first full moon occurred on May 1. On the other hand, it will be a micromoon—the opposite of a supermoon. Instead of appearing larger and brighter, it will look slightly smaller and dimmer because it will be farther from Earth.

This occurs because the Moon’s orbit is not perfectly circular. On this occasion, the satellite will be approximately 406,000 kilometers from our planet. According to astronomer Gianluca Masi of the Virtual Telescope Project, it will appear about 6 percent smaller and 10 percent dimmer than an average full moon.

Where will this phenomenon be visible?

In the Northern Hemisphere, the Moon will appear alongside Antares, the brightest star in the constellation Scorpius. In the Southern Hemisphere—including countries such as Argentina and Chile—the spectacle will be even more special, as our satellite will temporarily occult that star.

Although the differences in size and brightness will be subtle, those who wish to follow the phenomenon in more detail will be able to watch it live via the Virtual Telescope Project’s livestream. The last blue moon occurred in 2023, and the next one will not be seen until December 31, 2028.