Cetus is a very large constellation. It is best viewed from October through January.
Click on image for full size
Windows to the Universe original image


The constellation Cetus represents the Sea Monster. It is one of the largest constellations known. Even the ancient people of Mesopotamia recognized this large constellation. They believed the figure was Tiamot, a magical dragon that was slain by the hero, Marduk.

In classical civilizations, the figure was the giant sea monster that almost ate Andromeda. King Cepheus and Queen Cassiopeia were forced leave their daughter chained to a cliff. When the monster came up to eat her, the hero Perseus defeated him and later married Andromeda.

Because Cetus is so large, there are only a few months that the complete figure is visible in the sky. Look for Cetus from October through January. His head is a circle near the constellation Taurus. His long body stretches towards the southwest. The larger circle in the constellation is the tail, not the body!

The brightest star in Cetus is called Deneb Kaitos, which is a combonation of Greek and Arabic that means "tail of the sea monster". It is located in the lower right corner of the constellation. The first variable star ever discovered is in the Sea Monster. It is called Mira, and was discovered in 1596 by David Fabricius. Mira is located right in the middle of the body.

Cetus does not lie near the Milky Way, which means that dimmer galaxies that can't normally be seen are clearly visible. A few galaxies and one nebula are located near the top of the circle that makes up Cetus' tail.

You might also be interested in:


The constellation of Cassiopeia is one of the most famous in the sky. It is very easy to identify the stars that are part of it because they have the shape of a W. Cassiopeia was the daughter of Arabus,...more

Mira - Flickering Red Giant

What's in a Name: Latin for Wonderful Claim to Fame: Humans have been watching this star with interest for over 300 years. It changes its luminosity over a 332 day period by both shrinking and cooling....more

King Cepheus

Cepheus is one of the oldest constellations in the night sky. He is a circumpolar constellation, circling around the North Star all year long. This house-shaped constellation is named after an ancient...more

Northern Hemisphere Constellations

Many different constellations fill the evening sky in the northern hemisphere. Depending on your location and the season, different constellations can be seen. Northern circumpolar constellations can be...more

Southern Hemisphere Constellations

Many different constellations fill the evening sky in the southern hemisphere. Depending on your location and the season, different constellations can be seen. Southern circumpolar constellations can be...more


The constellation Carina is known as the Keel, which is the bottom part of old ships. Carina was originally a part of Argo Navis, which was a huge boat in the night sky. It has since been divided into...more

It All Depends On Your Point Of View

In most cases, however, the stars that we see that seem to be "close" to each other actually are quite far apart, some stars are much closer or farther than others as is shown in the example below of Ursa...more

As the World Turns

In our time, scientists (and most people!) know that the constellations seem to move across the sky because the earth rotates on its axis. What, you may ask, does the turning of the earth have to do with...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA