Based on the latest national forecast, skies will be mainly clear on Monday evening across about half of the contiguous (48) United States, as costumed kids arrive at the door looking for candy or some other Halloween treat.
A storm system moving north-northeast from the Carolinas will, unfortunately, spread widespread clouds and precipitation across much of the Northeast and Middle Atlantic States, as well as part of the Ohio Valley and eastern Great Lakes. Meanwhile, a frontal system over the Pacific Northwest is also likely to spread clouds and precipitation over this region.
The rest of the country, however, will be in fine shape with a half-moon shining prominently in the evening sky.
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Halloween’s half moon
If you plan to accompany children around your neighborhood, you might want to enlighten them by pointing out some of the objects that will be visible in the sky. The first object to be noticed as the sky darkens will be Earth‘s nearest neighbor in space: the moon.
Indeed, here is the main celestial object that will attract everyone’s attention
On Halloween evening, our natural satellite will be only hours away from its half or first quarter phase. Although for most folks it will certainly appear to be at half phase, close inspection with binoculars or a telescope will reveal that the line separating the dark from the light side of the moon — called the terminator — is not exactly straight, but is ever-so-slightly concave; that is, having an outline that curves inward or to the right. Strictly speaking, what will be in our sky on trick-or-treat night will be a waxing (albeit very wide) crescent moon.
About an hour after sunset on Halloween as night is rapidly falling, we can see the moon hovering almost due south approximately one-quarter up from the horizon to the point directly overhead.
One might get the impression that showing off the moon through a simple pair of binoculars might be a bit of a comedown from using a telescope. And yet, even a casual glance at a first quarter moon through 7-power binoculars can show you more detail of the lunar landscape than was seen by Galileo who gazed upon its surface more than four centuries ago. The moon is by far, the most satisfying object that a youngster can observe. It appears the biggest and exhibits lots of surface features. And best of all, it shows well even in heavily light polluted cities.
Related: Can you see stars in light-polluted skies?
Dark zones on the lunar surface were referred to as “mare” (pronounced “Mar-rey”) or seas by the first observers to explore the lunar landscape with telescopes, though we know today that there is not a single drop of water in these regions.
If we could imagine the disk of the moon as the face of a clock, at roughly the 2:30 position and near the upper right limb is a roughly circular dark area called Mare Crisium (“Sea of Crises”).
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Immediately adjacent to the terminator, a bit above center is a larger circular dark zone known as Mare Serenitatis (“Sea of Serenity”) and immediately below that, or to the left of Mare Crisium is another dark region that will be of particular interest to your visitors to see: Mare Tranquillitatis (“Sea of Tranquillity”) — the first location on another world to be visited by humans.
Tell your young skywatchers that astronauts Neil Armstrong and Edwin “Buzz” Aldrin landed the Apollo 11 lunar module on what famously would become “Tranquility Base” on July 20, 1969.
And also point out how mountains, valleys and craters all stand out in sharp relief right along the terminator, demonstrating just how rough and rugged the lunar terrain really is.
If you’re looking for a telescope or binoculars to observe the moon in more detail, our guides for the best binoculars deals and the best telescope deals now can help. Our best cameras for astrophotography and best lenses for astrophotography can also help you prepare to capture the next skywatching sight on your own.
Fancy taking a more in-depth moonlit tour of our rocky companion? Our ultimate guide to observing the moon will help you plan your next skywatching venture whether it be exploring the lunar seas, mountainous terrain, or the many craters that blanket the landscape. You can also see where astronauts, rovers and landers have ventured with our Apollo landing sites observing guide.
Saturn and Jupiter on Halloween
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After the moon, the next two objects that will attract attention will be the planets Saturn and Jupiter; about an hour after sunset Saturn will be passing its highest point in the sky, about 15 degrees to the upper left of the moon. Remember that your clenched fist held at arm’s length is approximately equal to 10 degrees in width, so Saturn appears roughly “one and a half fists” from the moon; it shines like a bright star with a sedate yellow tint. Many consider Saturn the most beautiful of all the planets. Its rings are still wide-open, with the north face tilted some 15 degrees to our line of sight. A telescope magnifying 30-power will bring them out; through a 4-inch telescope at 100-power, they are readily seen, while the view through larger instruments is jaw-dropping. Be prepared to hear exclamations from your young audience like “Awesome!” and “No Way!”
And you can’t miss Jupiter — the largest planet in our solar system. It will be far over to the left of the moon, about one-third up in the southeast sky, appearing to shine with a very bright, silvery-white light. With even a small telescope using low magnification you’ll be able to see its disk as well as all four of the famous Galilean satellites, so named because Galileo Galilei was the first to see them with his own crude telescope in 1610. On this Halloween night, you’ll see one satellite all by itself on one side of Jupiter — that will be Ganymede — while the other three reside on the other side of Jupiter. Going outward from Jupiter — relatively close to each other — will be Europa, Io and finally Callisto.
Related: The 10 weirdest moons in the solar system
Mars on Halloween
There’s another, very bright and more colorful planet that will also attract the attention of most folks: Mars, a very bright, fiery-colored object hovering low the east-northeast sky at around 8:30 p.m. local daylight time. Its reddish-orange tinge suggested the color of blood which is why this planet was named for the Roman god of war.
One month after Halloween, Mars will make the closest approach to Earth until 2033. Its distance from us on Halloween night will be 57.6 million miles (92.7 million km) and it is virtually a match for brilliance with Sirius, the Dog Star — the brightest star in the night sky Jupiter for brilliance at magnitude minus 1.2. Through even a small telescope it will show up as a small orange-yellow disk with some darker markings streaked across its surface. Admittedly not as impressive as Jupiter’s moons or Saturn’s rings, but still, some of your neighborhood ghosts and goblins will likely want to see it nonetheless.
Halloween fireballs
Because they are active over Halloween, and they displayed an impressive outburst in 2005 at the end of October, the Taurid meteor shower are sometimes called the “Halloween Fireballs.” The bits of debris that make up the Taurids are a little larger than average so they can result in brighter meteors and even fireballs, or exploding meteors (called bolides), that streak across the sky and leave incandescent trains in their wake.
While they are most active during the second week of November, a few forerunners can show up on Halloween night, darting from out of the east-northeast part of the sky. So, if you or your young visitors see something resembling a flare from a Roman candle sweeping majestically across the evening sky, it may very well be a Taurid meteor.
Related: How to photograph meteors and meteor showers
Helpful hints for young telescope viewers
In the September 2019 issue of The Astronomical League Magazine “Reflector,” author Richard W. Schmude Jr., offered some tips for those who plan to do public outreach for astronomy on Halloween:
“Firstly, children sometimes grab or touch the eyepiece, so use an inexpensive one. I gently warn children not to touch the telescope. In my area, parents have learned to tell their children not to touch the telescope. In some cases, a child will grab the eyepiece, causing the telescope to shift. For this reason, a Dobsonian telescope with a good finderscope is a good choice for Halloween outreach. A small stool or booster ladder may help very small viewers. Sometimes, parents hold their children up to look through the eyepiece. One may also place a monitor-connected video camera in the telescope and people can easily see the object on a screen.” “Finally,” adds Mr. Schmude, “I have my bag of goodies next to my telescope so that the children get two treats!”
If you’re looking for a new telescope, check out our picks for the best telescopes for kids (opens in new tab), or just best telescope deals and discounts (opens in new tab) ahead of Black Friday.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium (opens in new tab). He writes about astronomy for Natural History magazine (opens in new tab), the Farmers’ Almanac (opens in new tab) and other publications. Follow us on Twitter @Spacedotcom (opens in new tab) and Facebook (opens in new tab).
