This is a digital image of the scientific illustration known as, Scenographia Systematis Copernicani (the Copernican System) by Andreas Cellarius(1596-1665). Cellarius produced this illustration for his book, Harmonia Macrocosmica; posthumously published in 1660. Look closely to see a Sun-centered image with the Earth’s positions relative to the Sun at the beginning of each season.
Click on image for full size
(c)1995 Visual Language, All Rights Reserved
The Changing Night Sky
If you look at the night sky at different times of the year you see
different constellations. This change is due to the motion of the
Earth in its orbit around the Sun. As the Earth revolves about the
Sun, the Sun appears to move through the constellations. Therefore,
different constellations will be visible in our night sky at different
times of the year. You can't see the stars if the Sun is near them!
Each day a few stars are visible in the east that were not visible the
night before. If you were to measure how much the sky shifted from one
day to the next you would discover that it shifts approximately one
degree per day. This should not be surprising because there are 365
days per year and 360 degrees in a circle, like that of the Earth's
orbit. The Sun appears to move about one degree in the sky per day as
the Earth goes around it, which means the the shift in the stars and
constellations we see each night must be about one degree.
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more
Andromeda is a "V" shaped constellation best viewed in Autumn if you live in the Northern Hemisphere. It was one of the earliest constellations to be recognized. Andromeda lies near the celestial north...more
Aquarius is a member of the Zodiac, a group of constellations that the Sun travels through each year. It is best viewed in autumn in the southern sky, although much of the northern hemisphere can see...more
Cancer, the Crab, is a member of the Zodiac, a group of constellations that the Sun travels through each year. Cancer spends half of the year in the sky. It first rises in December and is visible through...more
Canis Major is known as the Great Dog. In Greek myth, it is said that this constellation, along with Canis Minor, are Orion's hunting dogs. Canis Major was one of the most important constellations in...more
The constellation Capricornus represents the figure of either a goat or a sea-goat in the sky. It is believed to be the oldest constellation known. Capricornus is also a member of the Zodiac, a special...more
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...more
The unvarying aspect of the relationships of the stars' positions may have suggested to the ancients something that was analogous to their beliefs about the universe. It is not surprising that they chose...more