It’s a commonly asked question. As the Moon makes its regular orbital journey around the sky, it sometimes appears close to a particularly bright “star”.
Often these stars are not stars at all but planets. Mercury, Venus, Mars, Jupiter and Saturn can all appear close to the Moon. That is because their orbits around the Sun are on a similar plane to the Moon’s around the Earth.
These planets also appear much brighter than most stars. Apart from the planets, a handful of first-magnitude stars – some of the brightest in the sky – also lie along the path travelled by the Moon, and so you might spot one close to it.
Occasionally, the Moon will actually pass in front of and hide a star or planet. Such an event is known as an occultation.
Here is a list of dates when the Moon may be seen close to a bright planet or star.
2021
April 2: Antares
April 6: Saturn
April 7: Jupiter
April 15: Aldebaran
April 17: Mars
April 20: Pollux
April 22-23: Regulus
April 26: Spica
April 29: Antares
May 3-4: Saturn
May 5: Jupiter
May 12: Venus
May 13: Mercury
May 15-16: Mars
May 16: Pollux
May 19: Regulus
May 24: Spica
May 27: Antares
May 31: Saturn
June 1: Jupiter
The bright stars that can lie close to the Moon all lie in constellations of the Zodiac. That’s because the Moon’s path through the heavens stays close to the ecliptic, the imaginary line around the celestial sphere marking the plane of the Earth’s own orbit around the Sun.
If you could switch off daylight, you would see that the Sun travels the full length of the ecliptic over the course of each year.
In order of brilliance, the brightest stars that can therefore be seen near the Moon are Aldebaran in Taurus, Antares in Scorpius, Spica in Virgo, Pollux in Gemini, and Regulus in Leo. They are all “first magnitude” stars.
But the brightest “stars” that you may spot near the Moon are not going to be stars at all, but rather the planets Venus, Mars, Jupiter and Saturn. One might add Mercury, the innermost planet in the Solar System, though it is never seen in a dark sky, and so is less likely to be noticed, especially as the Moon will be a very fine crescent when near to it.