Maybe you’ve read in the news that Jupiter and Saturn will appear like one giant star, the closest they’ve been in hundreds of years, on December 21, 2020. We’ve prepared a slideshow about the conjunction to explain this cool event!
The first 7 slides are a basic introduction, including an outdoor, hands-on portion that all ages can do.
Slides marked with a blue star go into a little more depth about angular measurements.
Slides marked with a purple star are a fun, hands-on activity about the solar system that only requires a piece of paper and a pencil.
Most of the time when you go outside at night, you don’t want to encounter any bears. However, there are always bears around if you know where to look — up in the stars! Luckily these bears won’t be bothered by your presence.
The bears are the constellations known as Ursa Major and Ursa Minor, or the Greater Bear and the Lesser Bear. The stars that make up these constellations are almost always visible in the northern hemisphere. While the Greeks, Romans, and Native people of the Americas saw bears, other cultures saw a wagon, a plough, a coffin, and many other things. Since this is Bear Fest, we’ll focus on the bear stories.
The written history of Ursa Major and Ursa Minor goes back thousands of years. Ptolemy listed Ursa Major and Ursa Minor as one of 48 constellations in one of the earliest surviving books on astronomy. It is mentioned in even earlier works, such as a poem by Aratus in 275 BCE. In this blog post, the author lists myths going back even farther in history.
As with many stories from history, there is more than one version of the myth of Ursa Major and Ursa Minor. One version is that Ursa Major represents Callisto who had a child with Zeus, king of the Greek gods. When Zeus’ wife, Hera, found out, she turned Callisto into a bear. Then one day Callisto’s son was out hunting and saw a great bear, not realizing it was his mother. To save them both Zeus threw them into the sky. Callisto became Ursa Major and her son, Arcus, became Ursa Minor. In other stories, Zeus turned Callisto into the bear to hide her from Hera. Other stories use the Roman form of the gods, Jupiter and Juno.
The bears in ancient Greece were Eurasian brown bears that are related to the grizzly bears found in North America. These bears are different from the black bears that live in New Mexico. Currently, there are estimated to be 450 brown bears living in the mountains of Greece. In general, bears are in declining numbers in Europe due to loss of habitat, but several groups in Greece are working to protect their bears.
In the drawing of Ursa Major based on the Greek myths, many people notice something unusual — the bear’s tail! Bears did not have long tails like this, even thousands of years ago. One story says that when Zeus threw the bear into the sky, he stretched out its tail. Interestingly, some of the Native people in the Americas told stories of a bear in this collection of stars. However, they did not see the handle of the dipper as a giant bear tail. Instead, the stars were seen hunters that were following the bear. As with the Greek and Roman myths, there are many versions of this story amongst Native people. Here is one version of an Iroquois story of the Hunting of the Great Bear.
Many of us are familiar with the Big Dipper. This group of stars is visible all year even in places with light pollution and is very recognizable. The dipper is not a constellation itself, but is called an “asterism” which is a collection of stars. While the Big Dipper is part of Ursa Major, it is not all of it. In the picture above you can see the dipper is just part of the larger bear. The Big Dipper is also known by other names around the world, such as the Plough, the Seven Sages, a boat, a salmon net, and others.
In addition to the fact that the Big Dipper is so easy to find, another reason this asterism is so widely known is that it helps people find north. Look at the above illustration of the two bears. The two stars at the end of the “bowl” of the Big Dipper point to Polaris, the North Star. Polaris also happens to be the end of the tail of the Little Dipper, but it is much easier to find the Big Dipper first.
In the last photograph, you can see all the stars rotating around the North Celestial Pole. Polaris is also shown so you can see how close it is to lining up with the pole. If you can find Polaris at night you can figure out what direction you are going.
Since the Big Dipper rotates around Polaris, you can use its position to approximate what time it is! Here’s an article on how to make your very own star clock. Try it out if you go camping or just in your own backyard. Just try not to disturb any wildlife that may also be out at night, like a real bear!
Also remember when you are looking at the stars that it is fun to look for constellations that other people recognize, but it is also fun to look for your own patterns in the stars. Maybe you can write your own story from what you see in the stars and send it to us!
This Saturday, June 20, 2020 is the summer solstice — the longest day of the year! This week on Take It Outside, learn about the science and traditions of the solstice. On Saturday, PEEC is also partnering with Los Alamos County for the Los Alamos County Campout.
Download the challenge sheet here to print out and complete at home. At the end of the challenge, you can either bring it to the nature center or mail it to us at 2600 Canyon Rd, Los Alamos, NM 87544.
If you don’t have a printer or prefer to work online, you can tell us about your experiences in the Google Form below or email your stories and pictures to firstname.lastname@example.org.
Astrophysicist and PEEC volunteer Rick Wallace introduces the science and traditions of the summer solstice in the following videos:
We’re posting three outdoor challenges today that you can enjoy throughout the week!
Tell us about your experiences with one, two, or all three of them! You can do this in the Google Form below, by writing or drawing about them on our summer challenge sheet, or by sending an email to email@example.com.
You don’t need equipment to get outdoors! Spending time in nature can improve mental and physical health for adults and children, and result in reduced stress. So spend some time outside today!
You can build a fort or tiny fairy houses, or just sit in a favorite spot and focus on each of your senses in turn. Read more and see our detailed suggestions on this page. The five senses mindfulness activity was one of our favorite outdoor challenges from the first 10 weeks of Take It Outside.
During the solstice, the sun reaches its highest point in the sky. Try tracking one or both of the following:
The length of your shadow at midday. As the sun gets higher, your shadow gets shorter! Every day, go outside at the same time, stand in the same place, and put a mark where the top of your shadow’s head is. Do you notice a pattern?
The position of the sun at sunset. Did you know that the sun doesn’t always set exactly in the west? The longer the day, the more time the sun spends above the horizon, and the further to the northwest the sun sets. Every evening at sunset, note where the sun sets compared to the landscape to the west. You can also mark the position with a marker on a west-facing window. Make sure never to look directly at the sun! Let us know what you notice!
Learn more about the summer solstice from EarthSky.
Share Your Experience:
Tell us about your outdoor experiences! We’d love to see your photos, too. Please send them to firstname.lastname@example.org or share them on Facebook or Instagram with the hashtag #peectakeitoutside. If you’d like this to count for the Summer Nature Challenge, be sure to include your name and email address.
Today we are learning about the sun, our primary source of heat and light on Earth. Make sure you don’t look directly at the Sun today because it can hurt your eyes!
We would like to know if there is interest in PEEC continuing Take It Outside once the nature center is able to open again to the public. If you would like to see it continue, please fill out our evaluation form.
PEEC volunteer and planetarium presenter Akkana Peck shares some interesting facts about the sun’s motion today on the blog. Check out today’s post here!
Make a sundial! A sundial is a solar clock: a device that tells time according to the direction of the sun’s shadow. You may have tried out the human sundial in the nature center’s garden.
You can use a sundial to tell time when you’re outdoors — no phone or watch required! They usually aren’t perfect representations of the time, but will give you a good estimate.
Your shadow moves throughout the day as Earth rotates and the sun appears to move across the sky. Test this yourself! Get a piece of chalk and find a sunny driveway or other clear place. Trace your shadow. Make sure to mark where your feet were. Come back again later, stand in the same place, and trace your shadow again. What changed? Is your shadow leaning the same way? Is it the same height? Can you figure out why it changed?
If you don’t have chalk, you can mark the position of your feet and the top of your shadow’s head with rocks. Return several more times during the day. What do you notice about the pattern the rocks make throughout the day? Share your observations with us using the form below. Be sure to take pictures and share them with us on Facebook or Instagram or by emailing email@example.com.
Outdoor Challenge (Advanced):
Take time today to trace out the sun’s path through the sky. You can do this activity using a camera or paper and pencil.
If you’re using a camera, use a tripod or rest your camera on a fencepost or similar stable object. Face south, and take a picture of the sky, including the horizon. Make sure never to look directly at the sun, not even through a camera’s viewfinder. Return several times during the day and take another picture of the same frame. In the evening, flip through your pictures to see how the sun moved through the sky during the day.
If you use paper, start by facing south and drawing the horizon line seen from your house on a piece of blank paper. Include prominent features, like trees or buildings. Go outside every two hours or so, and mark on your drawing where the sun is located. Make sure you don’t look directly at the sun! At the end of the day draw a line to connect the different positions of the sun. This will reveal the path of the sun at this time of the year.
The line the sun traced out is called the ecliptic line. You can imagine holding up a hula hoop across the sky that would cover this line. If you have a hula hoop, or a length of garden hose, try it! This line is special for several reasons. For one, it marks the plane of our solar system. In fact, if you go back out at night and look along the same imaginary line, you should see the moon and the planets fall roughly along it. The constellations of the Zodiac will be there too. Look for Gemini, Cancer, Leo, and Virgo in the evening sky at this time of year. Learn more about the ecliptic line here.
Consider redoing this activity as the season’s change and observe how the Earth’s tilt affects the sun’s place in the sky.
Check out this video to learn more about the Sun and how we get heat and light from it here on Earth!
The sun rises in the east and sets in the west, right?
This is true, but we’re not actually seeing the sun move. When the sun rises and sets, you’re seeing the effect of the earth rotating on its axis.
But put that aside for a moment. The sun does rise in the east and set in the west … but not always in the same place, and not always at the same time. And those changes are what causes our seasons, and a whole host of other weather phenomena.
The Earth’s axis is tilted about 23½ degrees. That means that as we make our yearly trip around the sun, part of the time Earth’s northern hemisphere is tilted toward the sun, and other times it’s tilted away.
When we’re tilted toward the sun, that means the sun rises earlier, sets later, and gets a lot higher in the sky. So it’s hotter, and we call that summer. When we’re tilted away from the sun, in winter, the sun stays lower and there are fewer hours of daylight, and so we’re a lot colder.
And those seasonal changes in how much sunlight we get cause all sorts of other effects — like ocean currents, the motion of the jet stream, and the seasonal warming that causes our crazy spring winds.
North and South Wanderings
The sun is farthest north on the summer solstice. This year, that’s June 20, and at noon the sun will be 77 degrees up (that’s 1 PM on our clocks due to Daylight Saving Time). We’ll have 14½ hours of daylight on that day.
On December 21, the winter solstice, the sun will only make it up to 30 degrees above the southern horizon at noon, and it will only stay up for 9½ hours.
This “solargraph” taken from Budapest used a pinhole camera (with actual old-fashioned film!) to capture the sun’s path through the sky over a whole year. You can see how much its path changes in summer versus winter.
Where Does the Sun Rise and Set?
Notice in the solargraph that the sun’s rising and setting position also changes over the year. It doesn’t rise exactly due east, or set exactly due west, except on the spring and fall equinoxes.
You can see this for yourself at home. Make a note of where the sun rises or sets today against a local landmark, like the Sangre de Cristo Mountains or Jemez Mountains if you can see them from your house. Then check again a week from today, and again in a month. How much does it change?
Be careful when doing this: don’t ever look at the sun directly, since it’s bright enough to hurt your eyes even when it’s rising or setting. Check it just as the last bit of the sun is disappearing behind the Jemez, or better yet, take a photo as it’s setting (but don’t look through the camera’s viewfinder, if it has one; just use the LCD screen).
There’s more to the sun’s motion than just north and south. Because the Earth’s orbit isn’t a perfect circle, sometimes we move faster in our orbit, sometimes slower. So sometimes the sun seems to lag a little behind, or race a little ahead, of where you’d think it should be — for instance, it might reach its highest point at 12:17 PM, or 11:46 AM, instead of exactly 12:00 PM noon (or 1 PM MDT).
If you pointed a wide-angle camera at the sky and took a photo every day at the same time over a whole year, sometimes the sun would be a little farther left, sometimes a little farther right, as well as moving north and south. You’d get a picture like a figure-eight, or a bowling pin:
That’s called the analemma. You may have seen it on globes of the Earth. The top of the figure-eight is near the summer solstice, when the sun is high; the bottom is near the winter solstice. If you take your photos at noon, the figure eight will be roughly vertical; if you take it in the morning or evening, it will be tilted, as in this morning analemma by Giuseppe Donatiello.
Take a closer look at the sun through today’s craft and outdoor challenges!