Taurus, The Bull, Challenges Orion, The Hunter
Last updated 1/20/2020 at 2:22pm
Orion, the hunter, is rising higher in the eastern sky each evening. Locate his belt marked by three bright stars in a row from east to west, Alnitak, Alnilam and Mintaka. Now, draw a line through his belt and extend it upwards towards the west; you’ll come to a bright red star, Aldebaran, the fierce eye of Taurus, the bull. The face of the bull is made up a group of stars forming a noticeable letter “V.” This is the famous Hyades star cluster. Although Aldebaran is the brightest star in the face of the bull, it is not actually a member of the Hyades cluster. Instead, it is what astronomers call a foreground star, one that lies in the same direction, but which is closer to us, only 67 light years away. This is less than half of the 153 light years to the Hyades. While there are many stars in the Hyades cluster, they are all at roughly the same distance since they were formed out of a single cloud of interstellar gas and dust at roughly the same time. The cluster has not had time to disperse around the Milky Way. Realize that, while the celestial sphere over our heads at first glance appears to be a two-dimensional spherical surface, it is not. Objects that appear to be close together in the sky often are at vastly different distances from us.
Since Orion is a fierce competitor of the bull, he holds up a shield made from the skin of a lion. This can be found in a faint arc of stars between Orion and Taurus. On the shoulder of the bull is a small cluster of stars that some people mistake for the Little Dipper. This is the Pleiades or the “Seven Sisters.” In the tradition of the Native American Mono tribe, the Hyades were a group of mountain lion hunters while the Pleiades were their wives. As Earth rotates the hunters are eternally chasing their wives across the nighttime sky. To the Greeks, the Hyades and Pleiades were sisters.
For the moment we have two planets visible to the naked eye in the early evening. One is very noticeable; Venus is shining brightly well up in the southwest and can be spotted even before the sky is completely dark. After all, Venus is the second brightest nighttime object after the moon. We don’t fare so well with the other one. Mercury, the smallest planet, is also there buried in the evening twilight. It is only 10 days away from passing behind the sun as it switched from the morning to evening sky. It is now deeply embedded in the evening twilight too close to the sun for observation but might be spotted with binoculars or a telescope late in the month.
In the morning skies we don’t fare much better. Mars is rising about three hours before sunrise, so it is well up in the southeast by dawn. Technically, the two largest planets, Jupiter and Saturn, are also in the predawn sky. But Jupiter just came out from behind the sun on Dec. 27 and Saturn followed the king of the planets there just a week ago today. This means they really haven’t had time to separate themselves from the bright glare of our central star. It is possible that Jupiter will be spotted through a telescope or binoculars by the last few days of the month. But things will change over the next few months and by May we will see more of our fellow planets.
Mercury, an elusive planet, has just passed behind the sun. In the last few days of the month, it will be challenging to spot very low in the southwest immediately after sunset.
Venus is standing higher in the southwest each evening. The queen of the planets doesn’t set until more than three hours after sunset. So, it is truly our “evening star.”
Mars is still rising about three hours before the sun. The god of war has just passed by its stellar twin Antares, the heart of the scorpion.
Jupiter is now in the predawn sky. The king of the planets is just becoming visible in the morning twilight. By month’s end it rises over an hour before the sun.
Saturn is coming up out of the glare of the morning twilight. Saturn might be spotted the last few days of the month through binoculars or a telescope, but not the naked eye.
Jan. 24, 4:42 p.m. EST - New moon.
Feb. 1, 8:42 p.m. - First quarter moon.
(The Learning Center at PARI is a public not-for-profit 501 (c) (3) organization established in 1998. Located in the Pisgah National Forest. The Learning Center provides STEM educational programs at all levels, from K-12 through post-graduate research. For more information about the Learning Center at PARI and its programs, visit http://www.pari.edu.)