Watching Jupiter, Mercury, and Venus

These three planets, Jupiter (the Solar system biggest planet), Venus (our nearest planetary neighbor), and Mercury (the closest planet to the Sun), came very close to each other in the last days of May, 2013 and it was a rare treat to watch their conjunction.

The closest they came to each other was on May 26, and I was lucky enough to spot them in Los Angeles, probably not the best place for nightly sky observations due to the bright city lights, but at the same time a pretty good place to watch relatively bright celestial objects such as planets owing to the excellent weather conditions that Southern California is so well-known for.

On that evening, these three planets were forming a lovely, pretty much equilateral triangle as you can see in the picture below. That's what I saw too. Venus the brightest one, was lowest over the Western horizon, while Mercury that usually tends to barely rise over it, was clearly higher above it than the other two celestial wanderers.

The beautiful conjunction of Venus, Mercury and Jupiter captured by Thierry Legault.

I then watched them again on May 28-30. On May 30th, they were aligned pretty much in straight line, with Venus more or less halfway between Jupiter and Mercury, the latter, as before the highest planet above the horizon, though the dimmest of them all. Still, quite easy to spot ca 8:00-8:30 PM.

It is Mercury that is actually the closest right now and not Venus, about 170 million kilometers (105 million miles) distant, compared to 250 million km (150 million miles) for Venus and 910 million km (565 million miles) for Jupiter. Our planet is on average only about 150 million kilometers from the Sun and can be as close to Venus as 41 million kilometers, though only every other year.

Mercury is rather hard to spot, but it's the second time I have seen it in LA, the first time in April 2010, when it too was close to Venus making its observation much easier because of that.

You can still watch Mercury and Venus in June, but Jupiter will soon be gone from the evening sky. In fact, June is an excellent month to watch Mercury, this most elusive of planets known even to the ancients, but also good to watch Venus that will steadily rise above the horizon. The conjunction of these two planets will take place on June 20th.

Posted on June 2nd, 2013.