A trio of bright lights in the dawn sky will become a quartet for the next few days. The crescent Moon will join the planets Venus, Mars, and Saturn. It’ll be a short-lived combo, though, as the Moon will vanish quickly in the dawn twilight.

Venus is the brightest member of the trio. It’s the brilliant “morning star.” It rises in the east-southeast a little before first light. Much-fainter Saturn will stand just below Venus tomorrow, then farther to the lower right over the following days. And even-fainter Mars is off to their right.

The Moon will stand to the right of the trio tomorrow, but will cozy up just below the three planets on Monday. It’ll slide to the opposite side of the trio on Tuesday, and be much farther on Wednesday, just peeking through the glow of the late twilight.

As the Moon slides toward the Sun, its crescent will get thinner and thinner. Tomorrow, the Sun will light up about one-quarter of the lunar hemisphere that faces our way. By Tuesday, though, only about one-tenth will be in the sunshine.

Even as the Moon wanes, though, we’ll still be able to see the entire disk. That’s because it’s lit up by earthshine — sunlight reflecting off of planet Earth. It gives the lunar nightside a ghostly gray appearance. If you look through binoculars, there’s enough light to make out the lunar seas, highlands, and a few craters — a panorama made visible by our own planet.

We’ll talk more about earthshine next week.
 

Script by Damond Benningfield