Jupiter And The Moon Sure To Get Your Attention Tonight

The moon and Jupiter light up the eastern sky late tonight in the constellation Aries. This map shows the sky facing east around midnight. The Pleiades or Seven Sisters star cluster, well to the left of Jupiter, also comes up around that time. Created with Stellarium

Many people are out late on Friday and Saturday nights for one reason or another. If you’re one of them, take a look to the east around midnight tonight, and you’ll see the last quarter moon rising with Jupiter in tow. The brilliant planet will be positioned only a few degrees below the moon in the constellation of Aries the Ram. As we move into the wee hours, the duo will rise higher and appear even more spectacular.

This frame grab from the Virtual Moon Atlas shows the top or northern half of the moon tonight. Mare Imbrium, an enormous, lava-flooded impact basin, is circled in red. You can easily see it in binoculars along with the prominent craters Plato and Copernicus. Click photo to download a free version of the atlas. Credit: Christian Legrand and Patrick Chevalley

In binoculars, one of the moon’s most prominent “craters” is in full view tonight. Called Mare Imbrium (Sea of Showers), it’s so big, astronomers refer to it as a lunar impact basin. The mare’s dark expanse measures 712 miles across. The outermost ring is formed by the beautiful sweep of the Carpathians and Apennines to the south and southeast and the Caucasus to the east.  Plato and the mountainous regions near it help define the second ring, while the smallest – only 375 miles across –  is almost completely flooded over by lavas that bubbled up from the shattered crust after the impact.

Mare Imbrium or the Sea of Showers is highlighted in this map of the moon. The other large, dark spots are also basins created from asteroid impacts. More than 40 are known. Credit: NASA

Based on dating of rock samples returned from the region from the Apollo 11 and 12 missions, scientists estimate that a large asteroid struck the moon excavating the Imbrium basin 3.85 billion years ago. All three of these mountain ranges were created when heat and energy from the collision melted part of the moon’s crust and hurled billions of tons of debris across its surface.

Over the next several hundred million years, lavas rich in iron and titanium oozed from fractures in the crust and filled the basin. These cooled and crystallized like lavas on Earth into large, dark lava plains. While meteorites have continued to pepper the surface since then, most volcanic (lava) ended on the moon about 3 billion years ago.

The Sea of (monster asteroid) Showers is visible with the naked eye, too, but binoculars or a small telescope will help you see and appreciate the cool details that paint the picture of its origin.

16 Responses

    1. astrobob

      Hi Tor, at first I was a bit puzzled, but then it was obvious. The person doing the video zooms in very close in the last few minutes. What appears as two suns is of course just one sun — the only one we’ve got — split into two by distant clouds. As you look at the video, try to see both “suns” as chunks of one full disk. With the middle portion obscured by clouds, it really looks like two separate objects. Now that I think about it, I’ve seen this before myself, but in quick passing, without the opportunity to watch it up close the way the video shows.
      Notice that throughout the video the sun is moving normally from upper left to lower right at an angle to the horizon. During the “double sun” phenomenon, the left half of the sun gradually goes behind the cloud bank and diminishes in brightness, while the right half, which is not blocked by clouds, becomes brighter as the sun moves to the right. Later we see the full rim of the sun before it’s passes for a final time behind the cloud bank.

        1. astrobob

          Tor, yes, nature does play tricks, especially if we’re wishful thinkers. The first clip is an internal reflection within the optics of the camera. I find it amazing that the photographer doesn’t just look at the sun with his own eyes and see there’s only one sun in the sky. He seems to believe that his and not his own eyes! Notice about 1/3 through the video that the bar of cloud over the top sun is identical to the one over the lower sun — a clear sign of a reflection. Since the second image is a reflection, it’s fainter than the overexposed primary image of the sun. As a photographer, I’ve seen these many times with either cheap glass or cheap glass filters.

          The second clip with all the nice trees shows a beautiful, bright sundog, a meteorological phenomenon caused by refraction from low level ice crystals called ‘diamond dust’. Sundogs can be extremely brilliant. We had one here in Duluth, Minn. a few winters ago that looked exactly like the one filmed. A wonderful sight! See here for more info: http://tinyurl.com/3txbzkc and here for a gallery of similar: http://www.atoptics.co.uk/halo/dogim0.htm

    1. astrobob

      Carol, it just comes up directly on your screen. Since it takes so long to download (28MB), you have to sit and wait. Don’t leave your screen however. Once downloaded, it plays immediately … and there is no control or “back” button. To see it again you have to download again. I searched for an easier version, but this is the only one I came across the night before and the day I wrote the blog.

    1. astrobob

      Hi Brandon — remember, I wrote that you wouldn’t see them until late at night — around midnight, maybe a bit earlier if you have a very wide open view to the east.

      1. JennyJo

        I watched it last night at midnight and it was absolutely beautiful. The moon was crystal clear and surrounded by a hazy circle of silvery clouds, somewhat like a picture frame, and below the moon was Jupiter, wonderfully bright and clear. Even the dog seemed impressed. 🙂 As I walked back home I looked up and saw a “falling star”; I think it must have been a kappa Cygnide.

        1. astrobob

          Great description, JennyJo. Glad you got to see it. We had clear skies too. Very nice! I even spotted Jupiter near the moon in binoculars at 8:30 this morning.

  1. jessie leigh

    I SEE IT! IT IS SO BEAUTIFUL! i love this!

    Bob thanks for posting cool stuff! I love reading your blogs! So glad i found your site! : )

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