Dennis Mammana: Jokes aside, the Moon meets Uranus this week

A lunar occultation occurs when the Moon drifts in front of a more distant object — such as a planet, star, or star cluster — in its orbit around Earth, and occludes it from view for about an hour. (Illustration from Creators.com)

Continue. Break out all the jokes. You want it too. I’ve done it before, but honestly, they were all a lot funnier in seventh grade!

In a few days, the planet Uranus (pronounced YOU-rah-nus, btw) will experience what astronomers are calling a lunar occultation. Such an occultation occurs when the Moon drifts in front of a more distant object – such as a planet, star, or star cluster – in its orbit around Earth, and occupies it from view for about an hour.

Occlusions are important because they allow scientists to refine our knowledge of the Moon’s orbit and discover companion objects orbiting distant stars or planets. They can even tell us about a planet’s atmosphere while obscuring it.

This week, the distant planet Uranus will be the “star” of the show as the moon passes in front of it. Whether you can see the event depends on your weather, of course, but also on whether you have a small telescope or binoculars to observe and whether you are in the right place at the right time.

It will be visible from the western parts of the United States (including Alaska), northwestern Mexico, most of Canada, and even parts of Scandinavia.

If you have a small telescope — or possibly binoculars — you should see Uranus as a faint bluish-green dot on the moon’s east side. The moon will be quite bright that night so you may have trouble spotting the planet.

As the Moon drifts east in its orbit around Earth, it will creep up on the planet from the west and pass in front of it. Because viewers in different locations around the world view the event from different angles, its times will vary from location to location.

For example, on October 11, Uranus will disappear from Southern California around 9:47 p.m. and reappear on the other side around 10:34 p.m. PDT, while from Denver it will disappear around 11:08 p.m. MDT and reappear around 11:52 p.m MST.

To find out event times for your location, call your local planetarium, science museum, or observatory.

Or click here for more information. However, remember that the times there are in Universal Time (UT), so you’ll need to convert them to your local time. To get PDT, subtract 7 hours from UT. Subtract 6 hours from UT to get MDT, 5 hours for CDT and 4 hours for EDT.

Regardless of your location, it’s always important to start the watch at least 10-15 minutes early so you can watch the moon approach the planet across the sky. Spotting the planet’s reappearance is a bit more difficult, however, as it’s difficult to know exactly where it will appear on the moon’s rim.

As you watch the occultation, it may appear as if the planet is drifting behind the moon, but it is the moon that is moving. That night, Uranus will be 1.75 billion miles away while the moon will be just 240,000 miles away, so its movement will be much more apparent.

OK, enough science. You can now return to the jokes!

— Dennis Mammana is an astronomy writer, author, lecturer, and photographer working under the clear, dark skies of the Anza Borrego Desert in upstate San Diego County. Contact him at [email protected] and connect with him on Facebook: @dennismammana. Click here to read the previous columns. The opinions expressed are his own.