This week we’re going to use the constellation Orion, the Hunter, to find another constellation, Taurus the Bull, using Orion as a guide, and throw in seeing the planet Mars as a bonus. (Remember to put red tape over your flashlight to protect your night vision outside.)
First, use the chart to find Orion. Look in the southeastern sky about 7 p.m. for the three belt stars inside the rectangle that is Orion’s body. Now use the three belt stars and follow their line up and to the right about a hand span at arm’s length to see a bright pinkish star. This is Aldebaran, the eye of Taurus the bull. Aldebaran is a giant star, much bigger than our Sun and is reddish because it’s surface temperature is about 4,000 degrees cooler than our Sun. A “V” of dimmer stars to Aldebaran’s right make-up the face of the bull. This V of stars, the Hyades, is actually a cluster of nearby stars behind Aldebaran and about four times farther away. You can find the two horns of the bull to the left of Aldebaran and above Orion. (See the sky map.)
Now find Orion’s belt stars again and once more follow them up and to the right, but this time keep going beyond Aldebaran and about half as far as the distance from the belt to Aldebaran. Do you see what at first seems like a fuzzy cloud of light. Look closer and see how many dim stars you see. If it’s really clear and dark I usually see six stars. This is the famous Pleiades star cluster, also known as the seven sisters. A telescope will show several hundred stars. These are very young stars, only about 100 million years old!
Finally, if you were observant, you may have noticed that there is a bright pinkish “star” in the sky just above Arcturus that doesn’t appear on the sky chart. That’s because it isn’t a star! It is what the ancients called a “wanderer” (The Greek term for this is planetes; we say planet.) You’ve found the planet Mars! If you watch it carefully for the next week or so you’ll notice that it is moving relative to Aldebaran. That’s because Mars is moving in its orbit around the Sun, but Mars is only about 50 million miles away so we can notice its motion. The real stars are moving fast, but are so far away we don’t notice their movement in a lifetime. (Think how fast a low flying plane seems to move compared to a high-flying jet.)
Thanks to your and other nation’s tax funding there are currently seven active orbiters around Mars and three active rovers on the ground. There is even one amazing helicopter. We’re learning a lot about the Earth from them.
In future episodes of Our Cosmic Neighborhood, we’ll see how to recognize other planets and notice how they move in the sky. Research and discover Jupiter and Venus in the western sky for yourself this week. (https://skyandtelescope.org/interactive-sky-chart/)
As usual, contact me for questions or comments: James Hill, Mississippi NASA/JPL Solar System Ambassador. Jhill6333@gmail.com.
