Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

The Sciences

Time lapse: When the Moon ate Venus

Newsletter

Sign up for our email newsletter for the latest science news

On the morning of August 13 - 14 (depending on where you were in the world) the Moon slipped directly in front of Venus in the sky, an event called an occultation. It was cloudy here in Boulder so I missed it, but halfway across the world in Korea, astrophotographer Kwon O Chul had a magnificent view, and made this lovely time lapse video of the event.

[embed width="610"]http://vimeo.com/47640715[/embed]

Occultations like this are relatively rare. If all the planets and moons orbited the Sun in exactly the same plane - that is, if you looked at the solar system from the side and all the orbits aligned perfectly, like looking at a DVD from the side - we'd see occultations all the time. But in reality all the orbits are tilted a little bit. Venus circles the Sun in an orbit canted by about 3° compared to Earth's. The Moon's orbit is tilted by 5 °. The Moon orbits the Earth once per month or so, but it usually passes by Venus, missing it by a bit because the orbits aren't aligned. But sometimes, every few years, the dance comes together, and the Moon wil slip directly in front of Venus. An occultation is an amazing thing to see. I saw a lunar Venus occultation when I was a kid and just starting out as an amateur astronomer. It takes a few seconds for the Moon to cover a planet, so you can watch as the planet dims and then pops out when it gets completely covered. Also, the Moon commonly passes in front of stars, which are so far away and appear so small they just wink out, blip! You can get a list of upcoming occultations at the International Occultation Timing Association

website. If you get a chance to see the Moon occult a star, take it! Binoculars help a lot, and it's fun to watch the star just suddenly blink out.

Tip o' the dew shield to Astropixie.

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.

Subscribe

Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 75%

Subscribe

Already a subscriber? Register or Log In