This month is a great time to see four out of the five visible planets all lined up in the morning.
They all rise shortly before the sun, so you won't find them until the sky begins to lighten, but if you wait too long, they will be lost in the glare of the dawn. The best time to catch them is about 45 minutes before sunrise, about 5AM these days.
On Sunday the planets will be aligned like this:
Venus, being highest and brightest, is the easiest to spot, but you will still need to find a location with a clear and low horizon, as Venus will be only about 2 or 3 degrees (or fingers held at arms length) above the horizon. (See our previous post about
measuring angles in the sky). Next brightest is Jupiter to the left of Venus at magnitude -2. Jupiter is now about 2 degrees (fingers) to the left of Venus, but as the month progresses, Jupiter will pass by Venus (May 11) and rise higher in the sky, making it even easier to find.
Mercury is next, lower than Venus and about 1st magnitude, still bright but 5 time fainter than Jupiter. Being so low in the dense air will make it look even less bright, so you may need binoculars to find it. Finally comes Mars to the left of the group. Mars is only about 100th as bright as Venus, so it may be quite a challenge to see without binoculars.
The dance of the planets will continue all month, with Jupiter and Mars getting a bit higher.
Here is the scene on the 15th.
You can also watch this
video from
Sky & Telescope which shows their movement for each day of the month.
Interestingly, the planets are aligned on the boundary of the zodiac constellations, moving from Pisces to Aries. There's an interesting halachic discussion about whether or not this entrance into Aries requires a blessing of Oseh Ma'asseh Breshit ("Who does wonders of creation") for the same reason we made the once-in-28-years blessing on the Sun two years ago. But I'll have to save the details for my next post.
