Cosmic Ballet, Part 2

Despite dire warnings not to travel to Oregon for the solar eclipse, I went any way. Traffic was not as bad as predicted. My gamble that everyone going to Oregon would have left over the weekend paid off. My gamble that homeward-bound traffic would be going the opposite direction of where I was headed paid off. I even managed to get some pictures for those of you who weren't lucky enough to witness totality, which was a first for me.

Before totality, small chunk of sun missing from top right

The eclipse caused these funky curved shadows

Using your hands to make a pinhole viewer

Totality! The black circle is the moon, the white ring is the sun's corona

The sky was dark enough that some stars were visible. I think this is Venus.

The eclipse got underway just after 9 AM Pacific time, immediately preceded by a flock of birds flying overhead away from the sun. Was that related to the eclipse? I don't know. I don't recall seeing any birds until after the eclipse was over. It took a while to notice any changes in lighting, but as totality got closer it was like someone turning a dimmer switch until it got dark. At that point, the eclipse glasses came off, the pop of some fireworks, and the crowd at the nearby football field let out a cheer. It was oddly quiet and oddly dark for about a minute until there was a flash of light where the top of the sun came out from behind the moon and the dimmer switch turned the other way and daylight returned.
The next total solar eclipse to hit the US is in April 2024. At that time, I hope to be in the field studying how animals react to an eclipse. Not much is known because they are such an infrequent event. Many animals run on a solar (day-night) cycle and scientists like myself wonder what they do when night suddenly happens during the day for a brief period.
Stay tuned for more stories from the road following Nature Minute's great American road trip!

The Cosmic Ballet Continues

This Monday the United States will witness the rare and majestic total solar eclipse. Not all areas will see a total eclipse, but all of North America will see at least some of the sun disappear. While not a rare event, it is unusual for a total solar eclipse to cover such a large populated area. It seems like usually they happen only over the remotest part of the Pacific Ocean or exclusively at the South Pole. This eclipse will the first total solar eclipse to hit the US since 1979. That might not be too terribly long ago, but think about this: in 1979 there were still people alive who could remember the last time the Chicago Cubs won the World Series (1908) or fought in the war against Spain in 1898.

What is a solar eclipse? When the moon passes between the sun and Earth and casts a shadow on us, that’s a solar eclipse. They can only happen during a new moon, which is when the sun’s rays hit fully on the “dark side” of the moon, so it’s the only time you’ll ever see a new moon. New moons happen every 29 days, just like a full moon, but we don’t have a solar eclipse every month because of how the sun, moon, and Earth dance with each other.

Geometry of a solar eclipse- not to scale (from Nustem)

You’ll notice the sun is a lot higher in the sky now than it was in January. Because Earth is tipped about 23̊ as were orbit the sun while spinning in our tipped circle (which also wobbles) the sun appears to ride a squashed and stretched figure 8 across the sky called the elliptical. The moon does the same, but their ellipticals don’t always match. When they do, you get an eclipse.

Distance is also important. Neither Earth’s orbit nor the moon’s is circular; both are slightly elongated (an ellipse, hence the term elliptical) so sometimes the moon close enough to block out the sun during an eclipse and sometimes it fits inside the sun like a ring. This is called an annular eclipse. Like during a total eclipse, only a narrow band will see the annular eclipse, while everyone else gets to see a partial eclipse or nothing at all.

Annular eclipse (from Universe Today)

Partial eclipse (from Huffington Post)

Always practice safe eclipse viewing! Follow these tips from NASA. Never look directly at the sun, even during an eclipse. The only exception is during totality, and that is ONLY if you have totality where you are at, and it only lasts about a minute and a half. Use eclipse glasses- if you put them on and try to see anything but the sun, you should only see blackness. Sunglasses will not do the job. Never look at the sun through binoculars or a telescope, unless you have a solar filter. If your solar filter screws on to the eyepiece, it is junk- throw it away! If you don’t have any safe viewing equipment, make a pinhole viewer by poking a hole through a piece of cardboard and let the sun shine through. During the partial phase, you will see a spot of sunlight missing a chunk in the middle of the cardboard’s shadow.

I will be in Salem, Oregon for the eclipse, immediately preceding a very special Nature Minute road trip. Sorry, no live-blogging. I can’t blog while driving, and besides, there’s no wifi in the wilderness. Check back in September or follow along on Facebook for pictures and tales from the road.

This week's credits: Nustem, Huffington Post, Universe Today, and NASA  

Species of the Month

August’s Species of the Month is our first insect to be featured. A frequent sight during the summer is the differential grasshopper. There are many species of grasshopper around the world, this one is widespread through the US, although it is absent from some states. If you live in most of the US, odds are good that you’ve seen one. While we often think of them as a hopping insect (hence the name) they also fly. Here in Washington we don’t have the differential, but a large grasshopper here makes a clacking sound as it flies past. Along with crickets, the grasshopper is one of those critters I associate with the shortening days and cool nights as we begin transitioning into fall.

Adult differential grasshopper (from Bug Guide)

Scientific name: Melanoplus differentialis

Kingdom: Animalia (animals)

Class: Insecta (insects)

Order: Orthoptera (grasshoppers, crickets, and katydids)

Range: Mexico to Alaska via the Midwest and Prairie Provinces, southern New England to North Carolina, American Southwest

Habitat: Grassy areas

Lifespan: About a year

Diet: Grasses and forbs           

Predators: Mites, nematodes, bee flies, blister beetles, Scelionid wasps, Tachinidae flies, Sarcophagidae flies, skunks, shrews, moles, salamanders, snakes, toads, passerine birds

Conservation Status: Species of least concern

Grasshopper eggs (from ID Tools)

Other Information: The differential grasshopper is a crop pest in many areas where it is found. When congregated in large enough numbers, a swarm can be devastating. Egg packets are laid in soil, a half to two inches deep. Larvae hatch in spring and go through a series of molts before reaching adulthood in 40-60 days. They are noted for the dark chevrons on their jumping legs and come in many color morphs, ranging from to olive green to black to almost white. They are edible for humans and make good fishing bait.

Differential grasshopper nymph (from Cape May Wildlife)

This week’s information comes from Texas A&M, Insect Identification for the Casual Observer, and University of Kentucky. Photo credits: Bug Guide, ID Tools, Cape May Wildlife 

Do You Hear What I Hear?

Next time you head into nature, try to tune in to the sounds you hear. It can be hard to shut out the human world, especially in the urban wild. The sounds of nature can be quite soothing. I enjoy sitting by a river and listening to the water swirl over and around the rocks, each passing H₂O molecule making those rocks a little bit smaller and contributing sediment to the sea. I also enjoy the sounds of the sea: a chorus of gulls providing backing vocals to the endless roar of the ocean.

As relaxing as sounds may be for me, they are vital to the survival of the critters. Predators, especially owls, rely on the sound of their prey to find their next meal. Prey species rely on the sound of predators to make an escape. Both predator and prey use sound (among other signals) to communicate to each other. A whistling marmot might warn others of death from above, while the howling wolf warns others to stay away from the pack’s territory. Many different animals use sound to attract a mate.

Buzzing insects, bird song, and rolling thunder are all part of the natural soundscape. Like all things in the natural world, it is vanishing. Even in national parks, noise from traffic and the devises people haul into campgrounds drown out the natural soundscape. A hike into pristine wilderness, despite its seclusion, is not impervious to intrusion from commercial airliners passing overhead.

Song sparrow getting ready for his bug number

What does this mean for the critters? It’s too soon to say. A pair of National Park Service biologists are recording the soundscapes of our national parks as a catalog and for research. The goal is to find out of our noise is diminishing our enjoyment of the parks. I am willing to bet that the average person won’t even notice the noise we take into nature, but it’s a different story for the critters.

Kurt Fristrup and Bill McQuay capturing the natural soundscape of
Great Dunes National Park in Colorado

Another group of researchers is using sound recordings to determine the effectiveness of conservation projects. These researchers, working in Papua New Guinea (north of Australia), are trying to find a cheap and easy way to tell if their work is working. In a species rich ecosystem like a jungle, getting sound recordings of the many critters coming and going may be the answer. The monitoring system is relatively inexpensive and easy enough that the semi-primitive natives can do it, giving them a role in protecting the ecosystem around them.

Setting up acoustic monitoring in Papua New Guinea

Comparison between the soundscapes of continuous and fragmented
forest cover in Papua New Guinea

Next time you head into Nature, close your eyes and take a minute to listen to your surroundings. How many natural sounds do you hear, compared to man-made ones?

This week’s stories come from NPR (National Parks sound recording) and Cool Green Nature (Papua New Guinea research).