Have you been noticing a bright yellow star shining in the east/northeast at twilight, or higher in the east/southeast through the evening, or high in the south at midnight? If you’re thinking of the same bright star as me, you’re seeing Jupiter!
Actually, it is hard to mistake or miss. Jupiter is the fourth brightest object in the sky after the Sun, the Moon, and Venus, and it is pretty dominant in the east in the early evening right now, shining at magnitude –2.9, in southern Aries.
(Magnitude is a measure of brightness for the stars we see from Earth, and the smaller the number, the brighter the object. The Full Moon’s apparent magnitude is -12.5; Jupiter at its brightest is -2.7; our north star Polaris is 1.99; the naked eye limit is 6. It sounds weird, I know, but just remember that any magnitude number higher than 6 requires optical assistance (binoculars/telescope) to view, and the negative numbers are really bright. You can read more about the history of the system here and here.)
According to Sky & Telescope’s “This Week’s Sky at a Glance,” Jupiter will be the bright “star” to the lower left of the Moon on Monday evening (Nov. 7), and while the Moon and Jupiter will appear close together in our sky, Jupiter is 1,400 times farther away. Wow. The Moon is about 240,000 miles from Earth. Figure that one out with your astronomonsters!
I pointed Jupiter out to my 2-year-old last month, and he still looks for it every time he’s outside in the dark, shouting, “Jupiter!” when he sees it. He grabbed my hand the other night, saying, “C’mon, c’mon!” He wanted to go walking outside and exclaim over Jupiter and the Moon. I think I’ll have a little buddy to take on Full Moon Walks for sure now!
So, point out Jupiter to a kid in your life. Tell them that bright “star” is not a star at all, but the massive planet Jupiter. They’ll remember it, even if they are 2!
Better yet, if you have a telescope, a good spotting scope used for hunting, or even some decent binoculars, aim them at Jupiter and give the kid a look. You’ll be able to see up to four bright dots to the sides of the disc of Jupiter—those are the Galilean moons Io, Europa, Ganymede, or Callisto. You might just excite a child to love astronomy.
(We just had Halloween…I recall reading in a blog–I think from the Bad Astronomer, but I can’t find the original post now–that the astronoblogger had set up a telescope on Halloween to show Jupiter or Saturn to trick-or-treaters. File that away for next year, ok?)
Jupiter is pretty easy to keep track of in the night sky. The zodiac—the band of constellations through which the planets travel—consists of twelve constellations, and Jupiter takes about twelve years to orbit the Sun. That means it spends about one year in each of those constellations, so if you know where it is this year, next year it will be in the one next door. A child of 12 will be 1 in Jovian years. Kids might find it an interesting activity to figure out where Jupiter was when they were born, and then keep track of how many Jovian revolutions they have been around for.
For some more detailed tips on observing Jupiter, see this Sky & Telescope page and this guide from a 2006 observing project (a little dated in regards to planetary position, but there are still some good tips in there). For a comparison of photos of Jupiter without optics, with binoculars, and with a telescope, see this blog entry on Observing Jupiter from Home.
Keep looking up!