SkyTour

Welcome to the SkyWatch Sky Tour. Most of the tour will be dedicated to the constellations. Click on the arrow below (and throughout the tour) to navigate. Thanks especially to Marco Murara of the Associazione Astrofili Trentini who kindly gave permission to use his excellent constellation charts.

Ursa Major

What is a constellation?
The ancients would play a game of "connect the dots" with the stars and imagine pictures in the sky. A constellation is a simply an arbitrary group of stars that forms some sort of pattern in our sky. Since there is no sense of three-dimensional perspective when looking into space, the stars of a constellations may actually be far from each other. Their only "connection" is that they happen to appear together when seen from Earth.

If the stars of a constellation aren't really connected to each other, why bother with constellations at all?
When you want to familiarize yourself with a city, you don't start by learning the name of each street, but by looking at the major landmarks: the river, a monument, a particularly tall building. The constellations - although they are very arbitrary - are the landmarks of the sky. Without them, the sky is simply a bunch of random stars. But with the constellations, they sky has "neighborhoods". The more constellations you know, the more familiar the sky will become.

How many constellations are there?
There are officially 88 constellations. You will probably find some of the names familiar: Aquarius, Hercules, Capricorn. Others such as Microscopium (Microscope) and Sextans (Sextant) are more obscure (and probably deservedly so).

Do the constellations change?
Not within our lifetime. Stars do generally move a few kilometers per second and with special instruments this motion can sometimes be detected. But they are so far away, that a constellation's stars will appear fixed in position for centuries.

Do I need any special equipment?
Not really. A telescope is useless for looking at constellations because it shows such a small slice of the sky. The following two items are certainly not necessary for sky gazing, but they will increase your enjoyment.

1) Binoculars - Unlike a telescope there is no need to setup a pair of binoculars; you just point and look. There are many objects such as the Moon and Milky Way, which are well worth viewing through binoculars

2) The book The Stars - A New Way To See Them by H.A. Rey who is probably most famous for writing the "Curious George" series of children's books. The book is an entertaining introduction to the delights of sky gazing.

Will I be able to see all the constellations?
The SkyWatch Sky Tour will cover 40 of the most prominent constellations. But unless you happen to live directly on the equator there will be some constellations always under the horizon no matter when you look.

When is the best time for sky gazing?
You will receive a message about a particular constellation during the best time of the year for viewing that constellation at about 8:30 in the evening.

Where is the best place for sky gazing?
Ideally on a very high mount top, hundreds of miles away from any artificial lighting. For those of us who do not live high in the Andes this is not always possible. If you live in the country, this will be easier. Try to find some safe place close to home that has no artificial lighting within a few hundred meters or so. There was a small park outside of my apartment building that was perfect. Maybe you have a good view from up on the roof. There is little point in finding a perfect spot if it's an hour drive away and you can only get there every few weeks. If you live in the Northern Hemisphere, an unobstructed view of the southern horizon would be helpful. A clear view of the northern horizon is good for those "down under."