Pisces Constellatio Astronomy

Astronomy hasn't always been a science, it was at one time more closely connected to astrology than it currently is. But stalwart men of science continued to look up into the night sky and consider the universe beyond the world upon which they stood. These were men such as Isaac Newton, who recognized that other stars are suns just like ours, Galileo who first used a telescope to gaze into the heavens, and even people as far back as Ptolemy who formulated the geocentric planetary system around 100 AD. The universe is infinite, which means astronomy is infinite. So a choice has to be made to zero in on a smaller sub-set of astronomy. For our purposes, let's focus on Pisces constellation astronomy..

How can there be a whole discussion of a constellation and its astronomy? The constellations aren't just mythical beings imagined by ancient people. Every constellation contains a number of interstellar objects and phenomenon including stars, nebulae, and even entire galaxies. Pisces, for example, contains very few bright stars but does contain a unique galaxy from our point of view. Galaxy NGC629, or M74, is a spiral galaxy like our own Milky Way, and we can see its facing side. To us it's like an octopus reaching into space in all directions. To us it looks like a spiral someone might draw. Not with the naked eye, of course. Even with a hobbyist's telescope it would look like a tiny, blurred spot. But with a telescope of 12 inches aperture or more the spiral details will be visible.

Another unique feature of Pisces is that an important part of the Sun's path passes through Pisces today, where it did not when the constellations were first mapped. Pisces (Aries specifically) sees the sun pass through it, over the equator, as it makes its way north. It's a phenomenon, really a time, known as the Vernal Equinox. When the First Point of Aries was established in ancient times it was east of Pisces. It has, however, drifted into Pisces over the long centuries. The drift of celestial objects as seen from Earth is called precession. The Earth and everything in the universe move. Our sun and its home, the Milky Way galaxy move rapidly through the universe. Our solar system orbits the galactic center at about 220 kilometers per second. Since humans have kept records the solar system has traveled about 1/250th of a complete orbit. The galaxy too, as well as everything in the universe, also moves at a breakneck pace. Constellations are always shifting and in flux. The movement of Aries relative to Pisces reminds us of this fact.

It may not be as wide as the universe, but Pisces constellation astronomy has enough to keep anyone interested for a long time.