Space is full of distant objects called star clusters. A star cluster is a group of stars that are bound together by gravity. Most of these star clusters can only be seen through a telescope, while others are so dim that they can barely be seen. There is one cluster, however, that is easy to see with your eyes in winter. If you look at the constellation Taurus the bull you can see a fuzzy blotch of light. That bit of light is not a star but a group of many stars. This star cluster is called the Pleiades.

The Pleiades, or the seven sisters, are estimated to be between 75 and 150 million years old. Throughout their long history they have inspired many myths and legends. The word “Pleiades” may have derived from the Greek word meaning “to sail.” This is because the Pleiades can be seen over the Mediterranean from November to May, the period of time known as the sailing season. In Japan, the Pleiades are known as “Subaru.” The car company Subaru got its name from the star cluster, and its logo represents the six brightest stars of the Pleiades.

The logo for the Subaru car company is based on the six bright stars of the Pleiades.

The Kiowa, a Native American tribe, believe that the Pleiades are a group of seven young women who were chased by a group of bears. As they ran away the women prayed to the gods to save them. The gods answered their prayers by turning the piece of ground the women were on into a mountain. The mountain grew so high that the women touched the sky and became a stars.

Today the Pleiades are interesting to learn about both because of their myths and legends and because they are so visible in the sky. In April they are especially interesting to look at as the moon will be paying them a visit. On April ninth the crescent moon will pass right through the seven sisters. Usually when this happens the light of the moon is so bright that it washes out everything that’s around it. Luckily for sky watchers, this time around the moon will be only a very thin crescent, allowing the Pleiades to be seen. Keep an eye on Pleiades this month and learn more about the constellation Taurus below in this issue of Star Teacher.

Visit this Pleiades page for more information on the science and myths behind this star cluster.

Get up early to see this giant planet. Jupiter will rise at around 3 am at the beginning of the month. You can’t miss this planet – it’s one of the brightest things in the sky and can be found next to the teapot of Sagittarius.

Throughout the year a familiar sight lies in Maine’s northern sky. Seven stars trace out a recognizable pattern that can be seen on any clear night. This pattern has been famous throughout history, helping slaves find freedom in the north and guiding sailors home. This simple constellation is called the Big Dipper and is an especially easy pattern to spot in the April sky.

Look in the northern sky closer to the zenith (the highest point in the sky) than the horizon. You’ll see seven stars that form the shape of a dipper: three stars tracing out a handle and four more making a square bowl. This constellation is the starting point for spotting many other star patterns in the night sky.

In the springtime two very bright stars are just beginning to rise in the eastern sky. The Big Dipper can help to point out these stars. Arcturus is the first star the big dipper points to. All you have to do to find this star is imagine a line arcing from the handle of the Big Dipper. To remember this, think “arc to Arcturus.” Then, once you find Arcturus, you can keep going in that same line to find another bright star. This star is called Spica. To find these two stars, all you have to do is “arc to Arcturus and speed to Spica!”

The Big Dipper’s handle is not the only thing that can help sky watchers find constellations. The dipper’s cup is very useful as well! If you use the two stars at the end of the cup you can find the Big Dipper’s smaller counterpart, the Little Dipper. These two stars in the big dipper are sometimes called the pointer stars. The name fits, because pointing is exactly what they do! If you draw an imaginary line from these two stars to a somewhat bright star that lies halfway between the horizon and the zenith, you will have found Polaris. Polaris, also known as the North Star, is the star at the end of the handle of the Little Dipper. The Little Dipper is a lot like the Big Dipper. It too has seven stars that make a shape like a cup and a handle. This constellation is not as easy to spot as the Big Dipper is, though, but the North Star is easy to spot.

As the weather begins to get warmer this spring it will be more and more enjoyable to go outside at night and watch the stars. The Big Dipper is a good starting point for any evening of sky watching. For more ways the Big Dipper can guide you through the night sky, take a look at this constellation site.

First man in space – On April 12, 1961, Yuri Gagarin, a Russian astronaut, became the first man to go into Earth’s orbit. Gagarin stayed in flight for 108 minutes in his Vostok 1 space craft. This historic step into space heightened the worldwide scramble to explore what lies outside the Earth’s atmosphere. Less than a month after Russia’s accomplishment Alan Shepard became the first American in space.

April is a big month for the constellation Taurus. This fearsome bull houses the Pleiades star cluster, an object that will be getting a lot of attention as the moon draws close to it this month. Taurus is most easily seen by finding the bright red star Aldebaran. This star, known as the eye of the bull, lies in almost a straight line with the three stars that make the belt of Orion the hunter. Look for it low in the western sky in April. Taurus has a V shaped face, above which grow two long horns.

Taurus the bull has two different forms in Greek mythology. One myth tells of when the god Zeus fell in love with a mortal woman named Europa. He came to her in the form of a white bull so she would not be frightened of him. Another myth says that this bull was a gift from the god Poseidon to a king named Minos. At first the bull was calm and tame, but then Minos did something to anger Poseidon. In revenge, the god made the bull go wild. This bull was also supposed to have been the father of the terrible monster called the Minotaur. Today Taurus protects the seven sisters as they travel together through the night sky.

Spring is an exciting time in Maine. The snow melts, the ground thaws, and the flowers begin blooming. Soon it will be summer, when the warm temperatures will allow everyone to spend time outside. While it’s easy to see the ways in which winter and summer are different, it’s not so easy to see why. The reason behind winter’s chill and summer’s heat lies in the height of the sun.

In last month’s Star Teacher we talked about the ways in which the Earth’s tilt affects our seasons. Because the Earth tilts, during some parts of the year the northern hemisphere is tilted away from the sun, while at other times it is tilted towards the sun. This change in tilt can be observed from Earth by noting how high the sun is in the sky. In the winter time Maine is tilted away from the sun. Because of this the sun appears to cross lower in the sky. The opposite is true in the summer. When our part of the Earth is tilted towards the sun the sun appears to cross high in the sky.

What does the height of the sun have to do with how warm the Earth is? In the winter time the light and heat from the sun comes to the Earth at a lower angle, while in the summer time the light and heat from the sun is more perpendicular to the Earth’s surface. In the summer time the sun’s heat is more concentrated, which leads to higher temperatures. For a more in-depth exlanation of this principle and an activity to aid students' understanding, try this Angled Sunlight activity.