#bioPGH Blog: The Leonids Meteor Shower
A resource of Biophilia: Pittsburgh, #bioPGH is a weekly blog and social media series that aims to encourage both children and adults to reconnect with nature and enjoy what each of our distinctive seasons has to offer.
On December 19, 1865, German astronomer Ernst Wilhelm Tempel was working in the Observatory in Marseille, France, when he made an exciting discovery: a previously unknown comet was making its way across the night sky. Only a few weeks later, on January 5, 1866, American astronomer Horace Tuttle independently noted the same comet from Harvard College Observatory in Massachusetts. The comet was named Comet Tempel-Tuttle in our honor of the two star-watchers, and this weekend, we will have the opportunity to see an annual reminder of that comet’s existence: the Leonid meteor shower. In anticipation of the meteor shower, I did a little astronomical digging and learned there is more to a comet than I realized; let’s explore a bit and then talk about the best way to see the upcoming shower!
A comet is an icy, rocky conglomeration of materials that orbits our sun (as opposed to asteroids, which also orbit our sun, but are solid rock and metal). Because comets are composed of a fair bit of ice, their surfaces are rather unstable as they approach the sun. Bits of ice will melt, boil and steam off the surface of the comet, taking little chunks of rock with them—much of which becomes the tail of a comet. However, contrary to popular legend, a meteor shower is not actually from the comet’s tail. The tails arc away from the sun, and thus do not end up in the orbit of the comet.
A meteor shower actually comes from the general debris of little “comet bits” that are left behind in the comet’s orbit. When the Earth passes through that debris, the bits of materials burn up in our atmosphere, creating a meteor shower. And yes—to answer the question that probably just popped in your mind—we will indeed pass through the orbit of the comet. Not to worry, though; the closest we will ever come to comet itself is roughly 788,000 miles (the Earth MOID - Minimum Orbit Intersection Distance), and that only happens once every 33 years for Comet Tempel-Tuttle. (You can see the orbit in the graphic below. Earth and its orbit is in dark blue; the comet and its orbit is in purple.)
Source: Image was created by Wikimedia user Pheonix7777 using the NASA HORIZONS System dataset. CC-BY-SA-4.0. The yellow dot in the center is the sun, the dark blue dot and line is the Earth and its orbit, the light blue is Mars and its orbit, the the outter yellow dot and line is Jupiter, and the purple dot and line represents Comet Tempel-Tuttle and its orbit.
The Leonid meteor shower, so named because the meteors will seem to radiate from the constellation Leo, have already begun, but will peak November 16-17, with the best viewing being in the few hours pre-dawn on Sunday morning. Because of bright city lights, you will need to be out of the city to view them, ideally in an area with minimal lighting. Most of our county parks would be suitable, or if you are up for a road trip, Cherry Springs State Park is known for star watching. To find Leo, face the eastern horizon; then lay down in a nice comfy spot on the ground and look up for the meteors.
I also checked in with Daniel Perrefort, PhD candidate in Astrophysics and Cosmology at the University of Pittsburgh, for extra insights in meteor shower viewing.
“First, always make sure to check the weather beforehand, especially in the colder months,” Daniel notes. “Bring jackets, blankets, handwarmers, and anything else you find appropriate. ‘Weather’ in this case also includes clouds and the phase of the moon. If it’s cloudy or a full moon, your viewing chances are going to be minimized.”
Daniel also suggested that if you need to bring flashlights, opt for lights with red filters.
“Some people bring flashlights for various reasons. However, if there is a flashlight shining nearby, you probably won’t be able to see any meteors. It also takes a while for the human eye to adjust to the darkness which plays a huge role since meteor showers don’t tend to be very bright (i.e., Don’t stare at your phone at full brightness). A good compromise is to use a red flashlight which doesn’t interfere with night vision. Even so, it’s good manners toward your fellow observers to turn it off when you’re not using it. “
Daniel’s last piece of advice, and probably my favorite: “Always bring snacks. Even if the weather is supposed to work in your favor, if it changes its mind and you can’t see anything the snacks help mild out the disappointment. Plus, who doesn’t like snacks!”
Connecting to the Outdoors Tip: Daniel pointed out that he now tends to plan his camping trips around meteor showers for optimal viewing: “A few years ago some friends and I were getting ready to call it a night on a camping trip in rural Pennsylvania (picture traditional farm country - no electric lights for miles). After dousing the fire and cleaning up camp, someone just happened to look up and pointed out that we were in the middle of a meteor shower. It wasn’t particularly bright, but we decided to stay up for another couple of hours and take it all in. Ever since then I’ve started scheduling my camping trips around meteor showers and it usually works out pretty great.”
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Photo Credits: Wikimedia User ForestWander CC-BY-SA-3.0 and NASA