The two words, “astronomy” and “astrology”, always seem to get confused. “Astrology” is often used when, in fact, “astronomy” is meant. The two words are only different by two letters and both are associated with real stars, but that’s where the similarity ends.

The following four points will help you learn the differences between astronomy and astrology so that you don’t make the mistake when talking about stars – whether they are the real ones or your horoscope!

So, what are the four BIG differences between “astronomy” and “astrology”?

Dictionary definitions

The following definitions are from the Australian Oxford Dictionary. They define the difference between the two terms:

“Astronomy – the scientific study of celestial bodies.”

“Astrology – the study of the supposed influence of celestial bodies on human affairs.”

You can see already that astronomy and astrology are very different to each other.

Milky Way over trees
A lot of people look to the stars to learn and aquire knowlege, but what we're all looking for can be quite different!

Who studies astronomy and who studies astrology?

Astrologers are the ones who gauge and predict the affect that the positions and motion of celestial bodies have on people and events.

Astronomers are the ones who make scientific studies of celestial bodies. Astronomers examine stars, planets, galaxies, nebula and much more to find out many things including how the Universe came to be.

Hubble Telescope
NASA uses the Hubble Telescope to study a variety of celestial bodies in deep space.

Looking forward or looking back

A horoscope or “your stars” is written for supposed influences on events in the future.

When astronomers study celestial bodies, they are looking into the past! It may sound strange but it’s because light takes time to travel from space to us here on Earth.

What is a light year?

The short answer is: about 9,500,000,000,000kms!

1 light year is equal to the distance that light travels in 1 year. Light travels at 300,000 kms/second and in one year this equates to about 9.5 trillion kms.

Think of a light year as a measurement of distance – just like 1m or 1km. Light years are used as a measurement in space simply because the distances are so great and metres and kilometres are just too impractical.

The Moon is the only object we see in (almost) real time. It only takes a couple of seconds for the Sun’s light reflected from the Moon to reach Earth. The Sun’s light takes about 8 minutes to reach Earth. And the light from Proxima Centauri, our next nearest star, takes over 4 years.

Light from far distant galaxies can take thousands or millions of years to reach our eyes. So, astronomers and stargazers are always looking at objects as they appeared in the past. If Proxima Centauri exploded or became a supernova yesterday, then we won’t know here on Earth for over four years!

What does it sounds like?

A horoscope will read something like this:

“Positive Mars boosts your passion for astronomy this year. You now have the enthusiasm to discover the stars and with persistence will find a way to join a local stargazing and astronomy club. Who would have thought it would be astrology to lead you to astronomy!?” 😊

A stargazing forecast from Stargazers Club WA will read:

“Venus is often referred to as the “evening star”, but it’s not a star at all. On summer evenings, Venus can be seen low on the western horizon. A good time to try finding Venus is at 7.30pm. Venus appears so bright because it’s covered by a layer of thick cloud filled with sulphuric acid crystals. The crystals in the cloud that covers the planet’s surface reflects the Sun's light extremely well. It dazzles us with its beauty here on Earth.”

There you have it. Astronomy and astrology are very different to each other! Hopefully you won’t get mixed up again.


Stargazers Club WA is especially for beginners! Come along to expand your mind about astronomy. We won’t be reading the stars… we’ll be looking at them! 😊 Non-members welcome.