Introduction

Watching the planets move against the background stars has been a fascination for millenia. You can imagine how the brighter planets changing their locations in the sky over weeks and months in a completely different way than the fixed stars would make their way into folklore and legends.

At present, the two brightest planets — Venus and Jupiter — are doing a dance in the early-evening sky. Venus is coming around in its orbit “catching up” to the Earth and has been rising higher and higher since the beginning of the year. Jupiter, meanwhile, has been going along it’s 11-year orbit around the Sun - it had it’s opposition back on January 10th and has been slowly sinking into the West; it’ll go behind the Sun in July, after which it’ll reappear in the early AM hours as a “morning star”.

The Encounter

Over the next few weeks, you can track them easily after sunset: Jupiter is in Gemini, and Venus in Taurus, but every night they’ll become closer and closer until June 8th/9th when they’ll get be at their closest: only 1.5°.

While it looks like they’re getting really “close together” in fact they’re very far apart in space: Venus in early May is about 130 million miles from the Earth (it can get as close as 24 million miles at inferior conjunction, though it’d be too close to the Sun to see). Jupiter is 520 million miles from the Earth - 4x times further away!

How it looks visually

After sunset, looking to the West you can’t miss them: they’re the brightest objects in the sky. Once it gets dark enough to see stars, you’ll see Castor and Pollux - the brightest two stars in Gemini - above Jupiter.

Here’s a few images showing what to expect taken every week:

Venus Meets Jupiter!

May 9th, 9PM
31° apart

May 16th, 9PM
24° apart

May 23rd, 9PM
17° apart

May 30th, 9PM
10° apart

June 8th, 9PM
1.5° apart!

Measuring the separation

One cool trick to making your own measurements between the two planets only requires using your fingers held at arms length! On average, the size of your pinky is ~1°, your index finger 1.5°. For larger angles, you can use your fist (about 10°) or the separation between your index finger and pinkie (about 15°) or thumb and pinkie (25°), and this also works for sizing up distances all over the sky.

At closest separation

As the two planets get closer to minimum separation, you can see them both either with binoculars, or with a very low power eyepiece (magnification 20x).

Binocular View
7x35

Telescope View
20x

Of course even in a small telescope, you can also see the changing of the “phase” of Venus, although over May it’s very subtle: Venus almost appears close to “full” and only changes subtly. However after it passes Jupiter in the sky, and is swinging around in its orbit, that phase will change dramatically, and it will start getting larger!

Wait! There’s more!

You might have noticed that starting late May, another planet starts creeping up over the horizon! Yes, Mercury also makes an appearance! This is a real challenge to find, since it’s only a few degrees over the horizon and usually hidden in the glare of twilight. If you do manage to detect it, you’ll see that its phase is very different than Venus - it’s close to a “half Mercury” (called a dichtomy) whereas Venus is mostly full, like a waxing gibbous Moon. (Venus will also be at dichotomy on August 12th and from there as it sinks lower to the horizon every night, will begin to show a crescent phase.)