A rare astronomical phenomenon will be observable Friday night in the western skies.

The Korea Astronomy and Space Science Institute says Mercury, Venus, Mars and Saturn and the moon will be able to be viewed simultaneously in the sky after the sun sets.

Mercury will disappear at around 8:30 p.m., but the other three planets and the moon will be able to be viewed simultaneously until 9:00 p.m.

The institute says the crescent moon affords the perfect conditions to observe planetary bodies.
The institute says the same phenomena will be viewable on Saturday night.