Early risers: something beautiful happened in the east in the wee hours of the morning, and it’s about to get even better.
Over the past month, four planets – Saturn, Mars, Venus and Jupiter – have marched upward from the eastern horizon.
But two are ready for a very close game. Saturday and Sunday morning, Venus and Jupiter will appear almost inseparable. They will be separated by less than half the width of a full moon.
These types of meetings – where two celestial bodies appear extremely close to each other in the sky – are called conjunctions.
That’s very cool! Jupiter, Venus and a crescent moon started moving across the sky yesterday morning. ShaughnessyB Photography with time lapse. #astronomy #moon #Jupiter #Venus pic.twitter.com/qvaziC0M5O
Of course, the pair is actually separated by some 650 million miles. Their orbits simply make them pass each other in the same patch of sky.
How and when to find them
If you want to get out of bed and have a look, the best time is before sunrise, around 5-5:30 am local time. And you’ll need to have a good view of the eastern horizon.
You will find two extremely bright “stars” closest to the horizon. They are Jupiter and Venus.
The two will be less than a degree apart – 0.2 degrees, to be precise – on April 30 and May 1.
Then, moving diagonally upwards to your right, you will see a faint reddish object: Mars.
And finally moving in the same direction, you will see Saturn.
If you want to see the conjunction better, you can use a pair of binoculars. Just be sure to put them away before the sun comes up. You don’t want to risk damaging your eyes.
After this conjunction, the pair will start moving away from each other in the sky.
The great thing about this conjunction is that it happens between two of the brightest planets in our sky. Venus is the brightest and is often referred to as the “morning star” or “evening star”, depending on where it is in the sky at the time of day. It has sometimes been mistaken for an airplane or, yes, even a UFO.
Jupiter is the second brightest planet in the sky and it’s hard to miss.
These planets are so bright because they have what astronomers call a high albedo (not to be confused with libido), a measure of how much light an object reflects. Venus appears so bright for two reasons: first, because it has a high albedo due to its thick cloud cover, and second, because it is so close to Earth.
In the case of Jupiter, it looks so bright because it’s so big (it’s the largest planet in our solar system) and also has a high albedo due to its cloud cover.
In astronomy, magnitude is a measure of an object’s brightness; the brighter it is, the lower the number. During the pair’s conjunction, Venus will be roughly at magnitude -4.11 and Jupiter will be at -2.11.
If you want to judge how different planets vary in brightness, you can compare Jupiter and Venus to nearby Mars and Saturn. Comparatively, Mars will be at magnitude 0.93 and Saturn at 0.79. Although still bright, they are nowhere near as bright as Venus and Jupiter.
If your forecast calls for clouds on Saturday or Sunday, you can still head out in the days ahead to see the daily movement of the planets, as well as the days after.