September and October bring a change of seasons on Earth—and a change above it as well. Although the skies might appear a bit bare after all the summer sparkle, the coming weeks offer sky-watching families a chance to glimpse pretty planetary lineups, cosmic time machines, and perhaps ghostly glows.
And with darkness setting in earlier each evening, kids can even explore the cosmos on school nights. So dust off those binoculars and telescopes to fill your stargazing calendar!
Light show in the sky
You might think of the stunning cosmic displays of the aurora borealis—otherwise known as the northern lights—as something only those in the far north can glimpse. But these shimmering and dancing glows increase in frequency during fall (though scientists are stumped as to why). That means even if you live in more southerly latitudes, you might be able to spot the show—sometimes the lights have been seen as far south as Florida and Mexico.
So what makes this cosmic light show glow? It begins on the surface of the sun, where giant clouds of high-energy particles are produced and ejected into space. Known as coronal mass ejections, or CMEs, these clouds travel at breakneck speeds to reach Earth in just two or three days.
When CMEs arrive, our planet’s magnetic field acts as a force field protecting us potentially damaging radiation, but some of the high-energy particles penetrate the atmosphere and collide with oxygen and nitrogen molecules in the air. That makes them glow like neon signs in shades of green, pink, red, and violet colors.
Sun-watching satellites can predict CME arrival times and intensities, but you’ll only get a few days warning. If a strong CME is headed your way (light pollution filters out the visibility of weaker ones), take a look outside around midnight, facing the northern horizon from as dark a location as possible.
Peek at some planets
There’s still plenty to see while your family is waiting for those ghostly glows. For instance, on September 14, Neptune—the solar system’s most distant planet—will be at its biggest and brightest in 2021. Use binoculars to look for a faint pinpoint in the southeastern sky tucked within the constellation Aquarius, the water bearer. (High magnification views through a small telescope show the planet as a blue-green disk.) For an easier quest, wait until September 19, when the planet will be parked next to the moon.
But before its visit with Neptune, the moon will pair up with two of the brightest and largest planets, Jupiter and Saturn. On September 16, look with your unaided eyes for Saturn snuggling close to the moon in the southeast evening sky. Train your small telescope on the planet, and its famous rings will come into focus.
The very next day, mighty Jupiter get its turn with the moon. Although your telescope will show off the gas giant’s cloud belts and cyclonic storms, a simple pair of binoculars can reveal its four largest moons.
And if September’s not good for your sky show schedule, wait for October 13 to 16, when the moon will pay another visit to these planets when it moves into this part of the sky again.
Or just before, on October 9 , look toward the low southwest horizon right after sunset for an eye-catching close encounter between the crescent moon and Venus. The second planet from the sun will be shining like a superbright star next to the stunningly thin crescent moon.
Dragon meteor showers
If your kids are Harry Potter fans, then they’ll love this next display: The minor Draconid meteor shower on October 7 and 8 will appear to radiate from the constellation Draco (the dragon, not Malfoy).
A near new moon will leave the dark skies perfect for viewing about 10 to 15 meteors an hour in the high northwest skies after nightfall. At the shower’s peak, Draco will be nearly overhead around midnight throughout the Northern Hemisphere. The dragon’s shooting stars are considered some of the slowest moving of any shower and are therefore fairly easy to spot.
Here’s a fun fact to tell kids: The flurry of meteors actually comes from a stream of sand-size particles spread along the orbit of a comet. When Earth slams into this debris stream, the comet particles disintegrate in the upper atmosphere, creating streaks of light.
Time traveling by sky
Finally, on the next moonless night in September or October, challenge your kids to spot the most distant object the unaided human eye can see: the great Andromeda galaxy! Start by looking high above the northeast horizon and find the bright neighboring constellation, Cassiopeia, the queen. The right side of this W-shaped pattern of stars will point directly down toward a small fuzzy patch of light.
Light pollution might make this galaxy challenging to see with the naked eye, but scanning the area with a pair of binoculars will make this celestial monster easy to hunt down from any backyard. The pinwheel-shaped galaxy shines with the combined light of a trillion suns—three times larger than our own Milky Way.
Here’s something that’ll blow kids’ minds: Unlike other relatively close twinkling sky lights, Andromeda is a staggering 2.5 million light-years away. That means the light from Andromeda left on its journey when woolly mammoths and saber-toothed cats roamed North America. Your family has, in essence, traveled 2.5 million years back in time!
Not bad for spending a bit of time under the night sky.