A beautiful crescent moon will glide between Jupiter, Saturn and Venus.
There is a lot of interest in supermoons this year, with the biggest, brightest moons of 2019 visible in January, February, and March. However, since a bright full moon can be difficult to look at for long, arguably the easiest and most beautiful time to observe our satellite is when it is a partly lit crescent moon.
This week, a crescent moon will sweep past no less than three closely aligned planets, but it will only be observable by those who get up before sunrise.
What is a crescent moon?
A crescent moon is a partly lit moon. During the course of its 29-day orbit of Earth, the moon appears to wax and wane. At all times, exactly 50 percent of the moon is lit by the sun, but because its position changes in space, we on Earth can only see a portion of its illuminated surface. During a full moon, Earth is between our satellite and the sun, so we can see a fully illuminated disc.
Two weeks later at New Moon (which occurs next on Wednesday, March 6), the moon is between Earth and the sun. Since only the far side of the moon is illuminated by the sun at that time, we see nothing at all. However, the week before New Moon sees a waning last quarter moon, and the crescent moon gets smaller and smaller every night until completely disappearing.
It’s a beautiful sight, and that’s exactly what’s happening this week in the predawn morning sky.
When to see the moon and Jupiter
On Thursday, Feb. 28, a 30-percent lit moon will be visible close to the giant planet Jupiter. You can see this by getting up well before sunrise at 06:31 a.m. EST and 06:23 a.m. PST, and if you do, there's a bonus. As well as being a big, bright planet that's easy to see with the naked eye, Jupiter has four large, bright moons. They can be studied in any small telescope, but Ganymede, Callisto, Io, and Europa can all also be seen through any pair of binoculars.
When to see the moon, Saturn, and Venus
A day later on Friday, March 1, 2019, a slimmer 22-percent lit crescent moon will appear just to the right of Saturn, very close to the ringed planet. Sunrise is at 6:30 a.m. EST and 6:21 a.m. PST on Friday. However, on Friday an even smaller 15-percent lit crescent moon will have moved beyond Saturn and will instead appear to be close to a super-bright Venus before sunrise at 6:28 a.m. EST and 6:20 a.m. PST.
When to see Venus, Saturn, and Jupiter together
Although you can see all of the planets in roughly the same position each morning this week, by Sunday morning the moon will be almost out of the way and very tricky to see. If you get up an hour before sunrise, which is at 6:27 a.m. EST and 6:19 a.m. PST on Sunday, you may just glimpse a super-slim 9-percent lit crescent moon to the lower left of Venus.
When will the planets be this close again?
It's worth taking a look at the eastern horizon if you're up early this week because in the coming weeks Venus — the brightest planet by far — will quickly become separated from Saturn and Jupiter as it moves closer to the sun.
However, on March 27, it will be possible to see a bright moon very close to Jupiter, and on March 29, right next to Saturn.