Weekend Sky Report / Full Moon
October 11, 2019
Sunday is the official full moon, but it’ll pretty much look full all weekend. It rises just after sundown, so it’ll be low on the southeastern horizon in the evening after dark. Often, this can make the moon look bigger, but it’s actually the same size in the sky as if it were straight overhead. A moon low on the horizon can also have a color like yellow, orange, or red. The reason for that is the same reason the sun seems to change color at sunset or sunrise… it’s seen shining through many more layers of atmosphere than if it were higher in the sky. So depending on the conditions, the moon can take on a certain hue.
All that aside, looking at a full moon through a telescope, you notice a lot. The craters, the so-called “seas,” the “Ocean of Storms—“ that’s the big sea… So just what are all those geographic features?
Well, the craters are pretty self-explanatory. They’re impact craters from the eons of the moon’s existence. Some of them are bigger than others, and some have some unique features. Take the Tycho crater. It’s the big one in the southern hemisphere with what looks like lines spiking off of it. That’s impact ejecta. Whatever made the Tycho crater was big enough to spray rock and dust so far across the moon’s surface that we can easily see it from Earth. And we know from samples taken on the Apollo 16 mission that Tycho is a relatively young moon crater, having formed an estimated 108 million years ago. Compare that to the much older “Seas,” which are left over from a time when the moon was geologically active. They’re vast plains of volcanic basalt—basically lava flows.
So take a moment to appreciate the full moon this weekend. Howling is optional.
Mar 27, 2020
If we're lucky enough to get clear skies in the early morning--before 7am Eastern, look to the south and you'll see three bright points of light. From left-to-right, it's Saturn, Mars, and Jupiter.
Mar 20, 2020
The Beehive Cluster is right smack in the middle of Cancer the Crab, which is actually a very dim constellation.
Mar 13, 2020
Blue stars that are really close to red stars can appear to us as a greenish blue. One good example is Antares B, the binary companion to the red giant Antares A, the heart of Scorpius.
Feb 28, 2020
Leo sweeps across the southern sky all night this time of year. In the evening, it's to the east. To find it, look for the Big Dipper. It'll be straight up and down with the cup at the top. Connect the two stars at the top that make up the end of the cup, and from that straight line, extend the line to the right toward the east, and when you hit the bright star Regulus, you've arrived.
Feb 21, 2020
Every good hunter needs support. Orion and his two dogs have reigned the evening sky in the winter since before human civilization. One of the earliest representations of Orion appeared in cave art dated more than 32,000 years ago.
Feb 14, 2020
On Tuesday morning, February 18, 2020, just after 7am Eastern, Mars will disappear behind the moon. An event known as a lunar occultation.
Feb 07, 2020
Sirius is a binary system consisting of the very bright, main sequence stage star we can see with the naked eye, Sirius A, and a much smaller companion white dwarf stage star, Sirius B.
Jan 31, 2020
Venus is 15 times brighter than the brightest star in the night sky, Sirius. And planets don't twinkle like stars do.
Jan 24, 2020
The Triangulum Galaxy gets its name from the constellation where it's found. It's a small constellation and, as the name suggests... it's a triangle.
Jan 17, 2020
The Orion Nebula is just over 1300 light years from our solar system, and it's believed to be an enormous 24 light years across. Because it's so big, and... relatively close, it's easily visible with binoculars or a telescope, even under fairly bright, suburban skies.
Jan 10, 2020
looking at a full moon through a telescope, you notice a lot. The craters, the so-called "seas," the "Ocean of Storms-" that's the big sea... So just what are all those geographic features?
Jan 03, 2020
Around 9pm, look low to the southeast to find the brightest star in the night sky. Bright white, twinkling Sirius. Above it, you'll see that iconic winter constellation Orion the Hunter. The orange star at his shoulder is the red supergiant Betelgeuse. Draw a line between Sirius and Betelgeuse, then look to the left, or east to find Procyon (PRO-see-on), another bright white star, and there you have it. A large, nearly perfect equilateral triangle of bright evening stars.
Dec 27, 2019
Betelgeuse is one of the largest stars we've ever discovered. If you were to replace the sun with Betelgeuse, it would engulf all four inner planets from Mercury to Mars, and, by some estimates, even Jupiter.
Dec 20, 2019
At 2300 light years away, the cluster resembles an upside-down Christmas tree with the brightest star representing the base of the tree. The other stars form a loose cone shape that makes it look like Christmas tree lights.
Dec 13, 2019
Auriga is home to three Messier objects, named after 18th century French astronomer Charles Messier, famous for his catalog of deep-sky objects. The three objects are all open clusters, which can be seen through most backyard telescopes.
Dec 09, 2019
The three stars that make up Orion's belt is the giveaway. But there's a lot more to appreciate.
Nov 29, 2019
A globular cluster is a densely-packed group of stars bound by their own collective gravity. The globular we're looking for tonight is Messier 15 -- also known as the Globular Cluster in Pegasus.
Nov 22, 2019
Lots of people can see just those three stars of Orion's belt and know what they're looking at. But look a little closer at the belt with a telescope, or even a good pair of binoculars, and you'll see many more stars.