Sunday, August 21, 2016

All Six Visible Planets - For A Limited Time!

We enjoyed some cool, partly cloudy skies this evening, so I stepped outside to check the twilight planets. And what a view! Low in the west, the trio of Venus, Mercury and Jupiter continue to impress. Just last weekend, the trio barely fit into the widest field of my 70-200 zoom lens. Tonight they easily fit into it set to 120mm, and the view will improve even more into next weekend. On Friday and Saturday (26th and 27th of August), Venus will be passing Jupiter and will be only .1 degree (1/5th of the Moon's diameter!) for a short time! The closest approach favors the east coast - by sunset here in Arizona on Saturday, Venus will already be past its closest approach, but perhaps observable during the day, if that gives you any ideas! Mercury continues to be the most difficult of the 3 to see, but it usually pops out as twilight continues to darken. If you try, make sure you have a good western horizon to see it before it sets! Make sure you click the image to see the planets better, and use the right image with labels for identification.

And, of course, that isn't all the show! To the south, Mars and Saturn continue to intrude into the constellation Scorpius. Mars is on the move again as Earth has passed it in its orbit. Just 6 weeks ago I imaged it well west of Scorpius. Now, as it has resumed prograde motion across the sky, it will pass the reddish star Antares in a couple days. Interestingly, the name Antares from the Greek is approximately "rival to Mars", and the colors closely resemble each other. If you go out to look, note that Mars does not twinkle, though Antares will. That is because the extended disks of the planets are less affected by atmospheric turbulence than the point sources of stars. Do get out and look for these guys and the twinkling effect. Saturn, in the outer reaches of the Solar System, moves much more slowly, so is tougher to see daily motion.

Note that in the title, I noted "All 6 visible planets", but only mention 5 here. The 6th one? Well, most of you see it every day - our own planet Earth! While Uranus is occasionally visible to the naked eye from a dark site, it isn't counted as a visible planet. So do get out and check out all 6 while they remain in the evening sky!

1 comment:

Irene Kitzman said...

Well, I was out walking as darkness came on, and saw Venus and Jupiter, but couldn't see Mercury through the haze. Saturn and Mars were spectacular! And while walking I grabbed a few neighbors out of a stroll and showed them the planets, and they were VERY excited. It might be nice to do this on a regular basis for the next several weeks as the night time air gets cooler.
Thanks for the photos!