A Beginner's Guide to Astronomy

What Is Astronomy?

Astronomy refers to the scientific study of everything in the universe beyond the Earth's atmosphere (which is approximately at an altitude of 100km), according to International law. Astronomy is an ancient field that seeks to understand the movements in the sky, celestial objects like stars, planets, galaxies, and the physical processes that govern them, from the humble origins of stargazing over millions of years, to studying the Universe on a deeper level using tools of modern science. This blog will provide an introduction to this fascinating science, from its historical roots to the modern tools we use today.

A Historical Look at Stargazing 

For millennia, humans have looked to the stars with a mix of curiosity and awe. Ancient civilizations used the movements of the sun, moon, and stars to track time, create calendars, and navigate the seas. In many cultures, celestial bodies were imbued with mythological and religious significance. The Babylonians and Greeks, for instance, were pioneers in observing and cataloguing the stars, laying the groundwork for modern celestial mapping.

The invention of the telescope in the 17th century revolutionised astronomy. With this new tool, we could see things previously invisible to the naked eye, such as the moons of Jupiter and the phases of Venus, which supported the heliocentric model of the solar system—the idea that planets orbit the sun.

Why Do We Study the Cosmos?

The drive to understand the universe is deeply ingrained in human nature. It's a quest to answer fundamental questions: What is the Universe? How did the universe begin? Are we alone? What is our place in the vast cosmos? Astronomy pushes the boundaries of our knowledge and has led to countless technological innovations and incredible human achievements. The very science of rocketry and space exploration is a direct result of our desire to travel to other worlds.

Tools of the Trade: How We Explore the Universe 

Modern astronomy relies on a diverse range of sophisticated tools to gather data from celestial objects.

• Telescopes: These are the most iconic tools of astronomy. Optical telescopes collect visible light, while others, like radio telescopes, detect radio waves. There are also space telescopes, such as the Hubble and James Webb, which orbit above Earth's atmosphere to provide crystal-clear images free from atmospheric distortion.
• Spectroscopes: These devices break down light into its individual wavelengths, or colours. By analysing a star's spectrum, astronomers can determine its chemical composition, temperature, and even how fast it's moving.
• Space Probes & Satellites: Unmanned spacecraft, like the Voyager probes and the Juno mission to Jupiter, travel to distant planets and moons to collect data up close. Satellites in Earth's orbit are also crucial for studying our planet and the sun. Over 200 space probes have been sent to explore celestial bodies in the solar system since the late 1950s. Additionally, thousands of satellites are currently in orbit around Earth. These satellites serve various purposes, including communication, Earth observation, and scientific research. These include approximately 1100 active satellites, and over 2000 dead satellites!

Starting Your Own Cosmic Journey 

You don't need a degree or expensive equipment to begin your journey in astronomy. The best way to start is by simply stepping outside on a clear dark night and looking up. Start by identifying the brightest stars and planets. Use a stargazing app on your smartphone, which can use your location to identify constellations and other celestial objects in real-time, or a star chart or planisphere. To observe the stars and planets, it is best to observe on a clear moonless night, away from any sources of light pollution. The best time to observe the Moon meanwhile, would be at a crescent or half moon, as this allows you to see the crater details along the terminator (shadow line). A simple pair of binoculars or an entry level telescope can reveal incredible detail on the Moon's surface and even show you the moons of Jupiter. As you learn more, you might consider getting a small telescope to see Saturn's rings or distant galaxies. The universe is a book waiting to be read, and every clear night offers a new page to turn.

Today, astronomy is a dynamic and exciting field that people of all ages and walks of life can participate in. It's a journey into the unknown that continues to expand our understanding of the universe and our place within it.