Sun, Moon and Stars: Patterns in the Sky

You can learn about the sky with a notebook and pencil. Start by looking carefully. Scientists call this observing.

Save what you notice

Ask yourself, “What shape can I see? Where is it?” Add, “What time is it?” Your sky journal keeps these details together. Put the date, time, and your watching place beside each drawing. Say whether the sky is clear or cloudy.

Here is one entry: “Tuesday, October 6, 7:30 in the evening. Back porch. Clear sky. A half Moon is above the oak tree.” The drawing shows the Moon's bright part. The words tell someone else when and where you saw it.

Choose one place to stand each time. A tree, roof, or hill can help you compare views. These things stay in place. We call them landmarks. Draw a simple skyline with the landmarks you can see.

Look again to find a pattern

A pattern happens again and again, in the same order. Day follows night, and night follows day. You need several observations to find a sky pattern. One round Moon drawing shows one moment. A page of Moon drawings shows how its bright shape changes.

Suppose you draw a shadow before school, at lunchtime, and after school. Put the drawings in time order. Look for what changed. Was the shadow longer or shorter? Did it point the same way? Keep the watching place and the object the same.

Clouds sometimes hide the view. Write “cloudy” when that happens. An empty view does not mean the Moon has gone away. Leave its shape unrecorded if you could not see it. A Moon calendar can help you learn what happened during the gap. Label that information as coming from the calendar.

Use your notes

A prediction says what you expect to happen next. It grows from a pattern you noticed. If sunrise has been near one hill all week, predict a similar place tomorrow. Then compare your prediction with a new observation.

Different patterns need different amounts of watching. Shadows change over a day. Moon shapes change over about a month. Long and short daylight periods return over a year. Photos, videos, and calendars help you study times when you are asleep.

Your eyes help you notice tiny details in the sky. Some sky watching needs special care. An adult can help you choose a safe place and method.

Keep sunlight out of your eyes

Never look straight at the Sun. This includes sunrise and sunset, even when the Sun looks orange. Its light can damage your eyes for good. The damage may happen without pain. Ordinary sunglasses do not make Sun watching safe.

Do not point binoculars, a telescope, or a camera toward the Sun and look through it. These tools gather strong sunlight. Special solar viewers are different from sunglasses. An adult must check and supervise any viewer made for looking at the Sun.

For our Sun records, use shadows. Look down at a stick's shadow. The Sun is on the opposite side. An adult can also help you use a photograph to study its place above a roof or tree.

Make a picture with a tiny hole

A pinhole viewer makes a small picture of the Sun on a card. Ask an adult to make a tiny hole in one card. Take a second, plain white card outside too.

1. Stand with your back toward the Sun.
2. Hold the card with the hole above the white card.
3. Let sunlight pass through the hole onto the white card.
4. Watch the small bright picture on the white card.

Look at the picture, never through the hole. You can move the cards a little to make the picture clearer. Your adult can help line them up while you keep facing away from the Sun.

Get ready for night watching

You can look at the Moon and stars with your eyes. Their light is much weaker than sunlight. Binoculars or a telescope can show more detail at night.

Go with an adult to a safe place away from roads. Wear warm clothes. Give your eyes about 20 minutes away from bright lights. More faint stars will become visible as your eyes get used to the dark. A bright screen or white flashlight makes faint stars harder to see again. A dim red flashlight helps you read your journal.

For long daytime activities, wear a hat and sunscreen. Take breaks in the shade. Set out your notebook and tools before you begin, so you can stay in your chosen watching place.

The Sun seems to cross the sky while you play and learn. Its place changes slowly through the day. You can follow that path using a shadow record or photographs.

From sunrise to sunset

The horizon is where distant land or sea seems to meet the sky. Sunrise is when the Sun comes up above it. Sunset is when the Sun goes below it.

The Sun rises on the eastern side of the sky. It climbs higher through the morning. Around the middle of the day, it reaches its highest place. It gets lower through the afternoon and sets on the western side.

In most of the United States, the highest Sun is toward the south. It is not straight above your head. In Australia and New Zealand, the highest Sun is toward the north.

Put the day's views in order

Think about a class watching from one playground spot. Their record shows three views:

Start with the morning view. Next comes the highest view. The last view is low on the other side. Joining these views gives a curved path across the sky.

The highest Sun does not always come at 12 o'clock. Clocks and the Sun do not line up exactly. In Chicago on April 15, the highest Sun comes around 12:50 in the afternoon. Moving summer clocks ahead often puts the highest Sun near 1 o'clock.

Use directions carefully

East, west, north, and south are directions. Face east: west is behind you. North is to your left, and south is to your right. Sunrise shows roughly east. Its exact spot changes during the year.

In the United States, summer sunrise is a little north of east. Winter sunrise is a little south of east. Summer sunset is a little north of west. Winter sunset is a little south of west. So the Sun follows the same kind of daily path, without using exactly the same spots all year.

When the Sun sets, it keeps shining. It has not sunk into the ground or sea. People on another part of Earth can still be in daylight.

A tree's shadow can stretch across the grass before school. Later, it may sit close to the tree. The changing shadow tells you about the Sun's place.

Read a shadow

A shadow forms when something blocks light. It points away from the Sun. Morning sunlight comes from the east, so a morning shadow points west. Afternoon sunlight comes from the west, so an afternoon shadow points east.

A low Sun makes a long shadow. A high Sun makes a short shadow. Around the middle of the day, an upright stick has its shortest shadow. In most of the United States, this shadow points north. The highest Sun is south of the stick. In Australia and New Zealand, the shortest shadow points south.

Keep a shadow-stick record

Choose a sunny, level spot. Stand a straight stick upright in clay or soil. Keep the stick in that spot all day. Its height and position must stay the same for each check.

Mark the shadow's tip with chalk or a small stone. Write the time beside the mark. Measure from the bottom of the stick to the tip. Check again every hour or two. Draw the stick and each shadow in your journal.

Here is a record for a 12-inch stick in Chicago on April 15:

Read downward. First the shadow gets shorter. It reaches its shortest length near the middle of the day. Then it gets longer. Its direction also changes: roughly west, then north, then east.

Connect two kinds of records

A skyline drawing shows roofs, trees, and hills from your watching spot. You can compare a Sun photograph with those landmarks. If the Sun's place is higher in the photograph, the stick's shadow should be shorter. If the Sun is lower, its shadow should be longer.

Measure from the stick’s bottom, not an earlier chalk mark. The distance between two tips is not the whole shadow’s length.

Clouds can make shadows faint or hide them. Write “cloudy; no clear shadow” for that check. Compare clear shadows when you can see their tips again.

Earth is a giant ball, and you live on its outside. The ground near your home looks flat because Earth is so big. Earth is also turning all the time.

A turning home

Earth spins, like a spinning top. One whole turn takes about 24 hours. That turn brings one day and one night to your home.

Imagine riding in a car past some trees. The trees seem to slide backward. You know the car is moving. A moving viewer can make other things seem to move.

The Sun's path is an apparent path. “Apparent” means it looks that way to you. Earth turns, and the Sun seems to cross your sky. Earth's spin also makes the Moon and most stars seem to cross from east to west. Earth itself spins toward the east.

Try a ball and flashlight model

Use a ball or globe for Earth. A flashlight stands for the Sun. Place a sticker on the ball for your home. Keep the flashlight still, shining on the ball.

1. Start with the sticker in the dark part. This models night.
2. Turn the ball so the sticker enters the light. This models morning.
3. Keep turning until the sticker faces the light. This models midday.
4. Turn it toward the dark part again. This models evening.

Keep turning in the same direction. The sticker returns to darkness, then light. You have made a repeating day-and-night pattern. The light stays on throughout the whole turn.

Day here, night somewhere else

When your side faces the Sun, it is daytime for you. At the same time, the other side faces away. It is nighttime there. When it is lunchtime in New York, it is the middle of the night in Australia.

The Sun does not switch off at bedtime. Your home has turned away from it. The model shows this: turning the ball changes the sticker's light, even though the flashlight stays on.

You do not feel Earth turning because it moves smoothly and steadily. You, the air, and the buildings move with it. Long ago, people often thought the Sun went around Earth each day. Watching from the ground makes it look that way. The turning-ball model helps explain what is happening.

Think about whether it is light or dark near bedtime. The answer can change as the months pass. Daylight is the time between sunrise and sunset.

Compare summer and winter

Summer has the most daylight. Winter has the least. Spring and fall are in between. This pattern repeats each year.

Chicago gives a clear example. Around June 21, sunrise is about 5:15 in the morning. Sunset is about 8:30 in the evening. There are about 15 hours of daylight. Around December 21, sunrise is about 7:15 in the morning. Sunset is about 4:20 in the afternoon. There are about 9 daylight hours.

You do not need to work out the hours to compare. In June, sunlight arrives earlier and lasts later. In December, it arrives later and ends earlier.

In the United States, the longest daylight comes around June 21. The shortest comes around December 21. Around March 20 and September 22, day and night each last about 12 hours.

Connect daylight and shadows

The summer Sun climbs higher around midday. The winter Sun stays lower. A 12-inch stick in Chicago makes a midday shadow about 4 inches long in late June. In late December, its midday shadow is about 26 inches long.

The same stick makes two very different shadows. The shorter shadow goes with the higher summer Sun. The longer shadow goes with the lower winter Sun.

Try a year record with an adult. Once a month, note whether it is light at the same clock time. Add the month and your place. Keep these notes through the year so you can compare seasons.

Other places have different year patterns

Australia and New Zealand have their longest days in December. Their shortest days come in June. Sydney has about 14 daylight hours in late December and about 10 in late June.

Near the equator, daylight changes very little. Quito, Ecuador, has about 12 hours in June and December. Near Earth's poles, the Sun can stay above the horizon for weeks. At another time of year, it can stay below the horizon for weeks.

Long US summer days do not mean Earth is closer to the Sun. Earth is a little closer in early January, during US winter. Moving clocks for daylight saving time also does not add daylight. It changes the clock labels for sunrise and sunset.

The Moon may look like a thin curve one evening. Later, it can look like a bright circle. These bright shapes are the Moon's phases. The Moon itself stays a whole ball.

Learn the shapes

A new moon is hard to see. Its lit half faces away from us. It is also close to the Sun in our sky.

A crescent is a thin, curved sliver. A half moon looks like half a circle. Gibbous means more than half a circle is bright, but not all. A full moon looks like a whole bright circle.

Follow this order:

1. New moon
2. Growing crescent
3. Growing half moon
4. Growing gibbous Moon
5. Full moon
6. Shrinking gibbous Moon
7. Shrinking half moon
8. Shrinking crescent
9. New moon again

The bright part grows from new to full. The word for growing is waxing. It shrinks from full to new. The word for shrinking is waning.

Why is a half moon called a quarter?

The growing half moon is the first quarter. It comes about one quarter of the way through the phase pattern. The shrinking half moon is the last quarter, also called third quarter. It comes about three quarters of the way through. There is one quarter of the pattern left.

“Quarter” tells you where you are in the pattern. Both quarter moons look like half circles.

Tell growing from shrinking

In an upright US sky picture, the growing Moon is bright on the right. The shrinking Moon is bright on the left. Think D O C: growing toward a D shape, full like O, then shrinking toward C. In Australia and New Zealand, the growing Moon is lit on the left.

Here is how to use the clue. A US observer sees a half moon bright on the right. This is first quarter. The next shape is growing gibbous, then full.

You can also compare drawings from several days. A bigger bright part means the Moon is waxing. A smaller bright part means it is waning. Follow the drawings in date order.

A Moon diary helps you see a pattern too slow for one night. Give each day a box on a calendar. Leave room for a drawing and a few words.

Fill a box with your observation

Draw the bright shape that you see. Add the date, time, and where you stood. Describe its place using a landmark. For example: “Low in the west above the school.” You can draw the Moon in the daytime too.

A clear evening is a good time to try. Some evenings, the Moon is elsewhere in the sky or has not risen yet. Keep a note of what you actually saw. If clouds hide it, write “cloudy.”

After several clear nights, compare the bright shapes. Continue for about a month. One full moon to the next takes about 29½ days. New moon to the next new moon takes that long too.

Follow the weeks

Starting at new moon, first quarter comes about one week later. Full moon comes about two weeks after new moon. Last quarter comes about three weeks after new moon. After a little more than four weeks, the new moon returns.

Suppose a calendar shows full moon on March 3. Another full moon will come around April 1. In between, new moon will come around March 17 or 18. These are approximate gaps, so a phase calendar helps you check particular dates.

Cloudy nights do not pause the pattern. The next clear view may show a bigger or smaller bright part. You can use a Moon calendar for the missing dates. Mark which information came from the calendar.

Find the Moon at different times

The Moon rises on the eastern side and sets on the western side. Earth's spin makes it appear to cross the sky. It rises about 50 minutes later each day, on average. So it will not stay above one tree at the same clock time.

First quarter is in the afternoon and evening sky. Last quarter is in the morning sky. Full moon rises around sunset and stays up through the night. The Moon can look pale against a blue daytime sky.

There are two changes to notice. During one night, the Moon crosses the sky, keeping almost the same shape. Over many days, its bright shape changes. Keep both its place and its shape in your diary so you can tell these patterns apart.

The Moon is a ball of rock. It does not make its own light. Sunlight bounces off its surface and travels to your eyes. We call this reflecting sunlight.

One lit half, different views

The Sun lights the half of the Moon facing it. The other half is dark. As the Moon travels around Earth, our view of the lit half changes.

At new moon, the lit half faces away from us. At full moon, we see the whole lit half. Between them, we see different amounts: crescent, half, or gibbous. A half moon does not mean sunlight has stopped lighting half of the ball. It means our view shows only part of that lit half.

The Moon takes about 27 days to travel once around Earth. The bright shapes take about 29½ days to repeat. Those are two different timings. Use about one month for the repeating shape pattern in your diary.

Make a Moon model

Ask an adult to help you set up a lamp in a darkened room. The lamp stands for the Sun. A ball on a stick stands for the Moon. Your head stands for Earth.

1. Hold the ball at arm's length, a little above your head.
2. Face the lamp with the ball between you and it. You see the dark side: new moon.
3. Turn slowly, carrying the ball around you. Look at its bright shape as you turn.
4. When the lamp is behind you, you see the whole bright half: full moon.

Keep the ball high enough that your head's shadow misses it. The lamp keeps lighting half the ball. Your view changes as the ball moves. The ball never changes its round shape.

What makes the monthly shapes?

Clouds can cover the Moon for a while. They do not make the regular phase pattern. That pattern comes from changing views of sunlight on the Moon.

Earth's shadow does not make the usual phases either. Sometimes Earth's shadow reaches a full moon. That different event is called a lunar eclipse. In the model, you keep your head's shadow off the ball to show ordinary phases.

The Moon is about one quarter as wide as Earth. It is about 239,000 miles (384,000 kilometers) away. It is much nearer than the Sun. Although it shines in our sky, it is not a star. A star makes its own light; the Moon reflects light.

On a clear, dark night, stars look like tiny lights. Each star is a giant ball of very hot, glowing gas. It makes its own light and heat.

Why night helps you see stars

The stars are still there during the day. Sunlight makes the daytime sky so bright that their faint light is hidden. Think of a flashlight on a sunny playground. Its light is much easier to notice in a dark room.

Stars look tiny because they are very far away. Many are bigger than the Sun. A small-looking point of light can be a huge star at a great distance.

Stars also seem to twinkle. Their light passes through moving air around Earth. The air changes the light's path a little, making the star seem to flicker.

Notice brightness and color

Some stars look brighter than others. Some look bluish-white, yellow, orange, or reddish. Sirius is the brightest star in our night sky. In Orion, Betelgeuse looks reddish, while Rigel looks bluish-white.

You can draw the brightest stars as larger dots. Add a color word if you notice one. A faint star can be hard to see from a bright street. Far from town lights, a clear night shows many more stars. A dark place can reveal a few thousand across the sky. A bright city may show only a few dozen.

Watch the stars change places

Over the night, most stars seem to travel from east to west. Earth is spinning, just as it does in the daytime. It makes stars seem to move across your view.

The North Star is different. It stays almost in one place in the northern sky. Other northern stars seem to circle around it. You can see the North Star from the United States. You cannot see it from Australia or New Zealand.

If you draw a star picture early and later, its place may change. The dots still keep their pattern. Use the same watching spot and include a roof or tree so you can compare the two views.

A quick bright streak is often called a “shooting star.” It is not one of these giant stars falling. It is a tiny piece of space rock or dust glowing as it rushes into Earth's air. A star picture does not lose a star when you see that streak.

The Sun is a star. It is the star closest to Earth. Its light and heat reach your home every day, even when clouds cover the sky.

Why does the Sun look different?

The Sun looks much bigger and brighter than the other stars because it is much closer. It is about 93 million miles (150 million kilometers) away. The next closest star is more than 250,000 times farther away than that.

Picture two matching flashlights. Put one nearby and one far away. The nearer light looks brighter. Distance changes how bright something looks. In the real sky, stars also differ in their size and the light they make. Many stars are larger or give off more light than the Sun. They look faint because they are so far away.

Even light takes time to cross these distances. Light from the Sun takes about 8 minutes to reach Earth. Light from the next closest star takes more than 4 years.

A huge, hot source of light

The Sun is so wide that about 109 Earths could fit side by side across it. More than a million Earths could fit inside. Its glowing surface is about 10,000 degrees Fahrenheit (5,500 degrees Celsius). That is far hotter than an oven.

Sunlight helps plants grow. People and animals depend on plants for food. We also depend on the Sun's warmth and light. Without it, Earth would be dark and frozen.

Compare the Sun and the Moon

Both can look like circles in the sky. They are not the same size. The Moon is much smaller and much closer. The Sun is much larger and farther away.

The Moon can be visible by day or night. Other stars are visible in the dark night sky. The Sun lights our daytime sky. Looking bright does not, by itself, make something a star. The important difference is whether it makes its own light. A bright full moon still reflects sunlight.

You can join bright stars in your mind like a dot-to-dot picture. People have imagined hunters, bears, and other shapes among them. These named star pictures help you find your way around the sky.

Find a picture one part at a time

A constellation has a named star picture. Scientists also use that name for its area of sky. There are 88 official constellation areas covering the whole sky. The stars in a picture can be very different distances from us. They only look close together from Earth.

The Big Dipper looks like a soup spoon. Four stars make its bowl. Three make its handle. Find the bowl first, then trace the handle. The Big Dipper is part of the Great Bear constellation. It is not a whole official constellation by itself.

Two stars on the outer edge of the bowl point toward the North Star. Follow the line from the bowl's bottom star through its top star and farther out. The North Star helps people find north because it stays almost still. It is not the brightest star.

Try other star pictures

Orion, the Hunter, has three bright belt stars in a short row. Find the belt before the rest of the hunter. Orion is easy to see on winter evenings in the United States. In Australia and New Zealand, it appears on summer evenings and looks upside down.

The Southern Cross looks like a small cross or kite. It is the smallest official constellation. People in Australia and New Zealand can see it, and it appears on both countries' flags. Most US observers cannot see it. US summer evenings show Scorpius, the Scorpion, low in the south.

One sky, many stories

A small star cluster called the Pleiades has many names. Old Greek stories and many Aboriginal Australian stories call it the Seven Sisters. It is Matariki to Māori people in New Zealand and Subaru in Japan. Different peoples made their own stories about the same stars.

The return of Matariki to the early morning winter sky marks the Māori New Year. Sailors have also used stars to find directions at sea. Familiar patterns helped people tell both direction and time of year.

A picture keeps its shape while its place changes. Draw the Big Dipper at 8 o'clock, then at 10. It has turned around the northern sky, but the bowl and handle still match. You can turn your notebook to compare the dots. Across a year, different star pictures return to the evening sky in different seasons.

Some sky changes fit into a day. Others take weeks or months. Choosing the right length of time helps you know when to look again.

Sort the repeating patterns

The day pattern comes from Earth's spin. The Moon’s trip around Earth brings the monthly phases. A little more than 12 Moon phase patterns fit into a year.

Most stars also seem to cross the sky during a night. Familiar star pictures return to the evening sky at the same season each year. So stars can help you notice both a night pattern and a year pattern.

Pick a useful waiting time

Imagine you have two questions: “Where will the Moon be later tonight?” and “When will the next full moon come?”

For its place, compare views a few hours apart. The Moon seems to cross the sky as Earth turns. For its full shape to return, compare dates about a month apart. Its shape stays almost the same during a single night.

For the daylight pattern, record whether it is light at the same time each month. This compares one time across the seasons.

Calendars follow the sky

Our ways of counting time grew from these patterns. Days follow day and night. Months grew from the Moon's pattern. The word “month” is related to “moon.” Years follow the returning seasons. In the Islamic calendar, months traditionally begin when the first thin new crescent is seen.

Not every calendar month lasts exactly one Moon cycle. Calendar pages can have different numbers of days. A Moon diary follows the shapes themselves, from one full moon to another.

Clouds, rainbows, and airplanes do not repeat on these regular sky schedules. A cloudy morning can hide the sunrise. The day pattern still continues behind the clouds. Your journal can record a hidden view without treating it as a missing sunrise.

Your sky notes can help you say what you expect next. A useful prediction gives a clear event, time, and place. Then you can go back and check it.

Turn a pattern into a prediction

Use four steps:

1. Observe. Record what you see.
2. Find the pattern. Compare several records.
3. Predict. Say what you expect next, when, and where.
4. Check. Make a new observation and compare.

Suppose sunrise has been near a water tower this week. Its place moves only a little from day to day. You can predict a sunrise near that tower tomorrow. A note such as “Around 7 tomorrow morning, low in the east near the tower” is easy to check.

Work through a Moon prediction

A US sky watcher sees a half moon bright on the right on October 6. First, use the bright side to identify first quarter. Next, follow the shape order: growing gibbous, then full. First quarter to full takes about a week.

Predict a full moon around October 13. About another week later, around October 20 or 21, predict last quarter. That half moon will be bright on the left in an upright US view. Put the dates in the diary and compare with a phase calendar or a clear view.

Use more than one clue

For a sunny morning, predict a long stick shadow pointing west. Around the middle of the day, predict the shortest shadow. In Chicago in late December, sunset comes around 4:20 in the afternoon. A trip home at 5 o'clock will be after sunset. In June, that time is before sunset.

For a clear US winter evening, Orion's belt is a good pattern to seek. The Big Dipper will keep the same bowl-and-handle shape it had last week. Its place in the sky can still change as the hours pass.

Check what happened

Return at your planned time and place. Compare the new record with the prediction. If clouds hide the Moon, write that down. You have not seen its shape yet. A phase calendar can help you check while you wait for clear skies.

If the view differs, compare your times and watching spots too. More observations may help. Predicting sunrise does not predict clear weather. You can know the Sun will rise tomorrow while still needing to wait to see whether clouds hide it.