Gijs Mulders

Faculty of Engineering and Science

“Unlike the position of the Sun, which is linked to the seasons through Earth’s rotation, tilt, and orbit, these five planets orbit the Sun independently.

Astronomy and astrology have similar names and some confuse them, but they are very different. Astronomy is the scientific study of the sky which aims, among other things, to understand the physics of the Universe. Astrology, on the other hand, is not a science and uses the apparent movement of stars and planets in the night sky to think about human relationships here on Earth. Although they have very different intentions, how come their names are so similar?

The reason for this similarity is that the origins of the two were linked in the past. These origins date back to Babylon, one of the cradles of civilization located in present-day Iraq. Fertile land between the Euphrates and Tigris rivers, where ancient cities arose where people began to observe, think and write about the night sky.

Agricultural societies needed calendars: to know when to sow and harvest, but also to know when to collect taxes and plan festivities. The night sky offered a calendar, if one knew how to read it. The priests of this civilization, who were also timekeepers, grouped the stars of the night sky into constellations.

vsWith the invention of the telescope, two other planets were discovered, Uranus and
Neptune.

They observed the sun rise and set in different constellations throughout the year, observing the positions of the stars. Because changes in the sky were accompanied by changes on Earth, the Babylonians believed that the movement of the stars above caused the seasons on the planet below: “As above, so below.” »

Much later, after the Copernican revolution, we understood that it is the Earth that moves, and not the sky. Thus, the rotation of the Earth causes the Sun to rise and set each day. Earth’s orbit causes the Sun to rise and set in different constellations throughout the year, while Earth’s axial tilt determines the seasons each year.

So it’s the opposite: the seasons are born on the Earth below, but are projected into the sky above: “As below, so above.” However, the above did not stop astrology. In addition to the daily and seasonal patterns of the stars in the sky, there are other movements: those of the planets (Mercury, Venus, Mars, Jupiter and Saturn) in relation to the stars.

The priests of Babylon thought, as in astrology, that this movement was attributed to what happens on Earth: the horoscope. But unlike the position of the Sun, which is linked to the seasons through Earth’s rotation, tilt, and orbit, these five planets orbit the Sun independently.

There is no common origin between the apparent movement of the planets and terrestrial phenomena. The positions of the planets above do not correspond to any phenomena occurring on Earth below: “As above, so below.”

On the contrary, astronomy has evolved in a completely different direction. With the invention of the telescope, two more planets, Uranus and Neptune, were discovered. With the construction of large telescopes, many of them in the Atacama Desert (Chile), planets have even been discovered around other stars, called exoplanets.

Using telescopes in space, astronomers have already discovered more than 5,000 exoplanets, and thousands more will be discovered in the years to come. By moving from planets to exoplanets, astronomers have given a different meaning. We already know that exoplanets are quite common in the cosmos, with one in five stars having planets that somewhat resemble Earth.

It is still unclear whether these worlds can support life… It is possible that life in the cosmos is not so rare, and that the life we ​​know on Earth could also be present around the stars visible in the sky nocturnal: “How are you?” down, is it up? “