An Introduction to the Night Sky: What is Space?

Integra Youth
May 14
4 min read

The Artemis missions are a series of missions to establish a long-term presence on the Moon and prepare for Mars. The recent Artemis II mission gained lots of attention and marked a major milestone in the history of space exploration as it was the first crewed mission, allowing four astronauts to travel further than 160 to 2000 km above Earth’s surface (also known as low Earth orbit) in 50 years. It was used to validate life support systems on the Orion spacecraft, a vehicle designed for future moon and Mars missions. These astronauts travelled to the same night sky we see every single day.

Space is everything beyond Earth’s sky and atmosphere. It is filled with millions of objects such as planets, moons, stars and black holes. Space may seem endless and look dark and empty, but it is full of amazing objects. They may be very close to us, while others are so far away that it takes years for their light to reach us. We are not able to see any of these things during the day--the reason for this is sunlight. During the day, the sun’s light is so bright that it becomes hard to see anything else beyond Earth. At night, however, the sun no longer shines on our side of the planet and the sky becomes dark, allowing us to see into space.

This same sky-- the one that looks so far away--is the same one that astronauts travel through. This is what makes space missions, such as the Artemis II, so special. Instead of simply looking at the night sky, the Artemis II crew will be INSIDE the night sky.

So, what kinds of objects are actually out there?

Stars

Giant balls of hot, glowing gas that produce their own light and heat. The closest star to Earth is the Sun, which provides all the energy required to live.

*Image of the Solar System (How Stuff Works, Mar 7 2024)*

Planets

Large objects that orbit (move around) a star. Unlike stars, planets do not make their own light; they reflect light from a nearby star. Earth is a planet – so is Mars, Jupiter, and Saturn.

Moons

Objects that orbit planets. Earth has one moon, but some planets have hundreds.

*Image of Asteroids, Comets, & Meteors (NISE, n.d)*

Comets and Asteroids

Some of the smaller objects in space. Asteroids are rocky space objects. Comets are made of ice and dust and can have long glowing tails when they get too close to the Sun.

Image of the Milky Way galaxy (National Geographic, Apr 19 2017)

Galaxies

Huge collection of stars, planets, gas, and dust all held together by gravity. We live in a galaxy called the Milky Way, but there is an estimate of 2 trillion galaxies.

Black Holes

Places in space with very strong gravity. They pull in anything that gets too close, even light!

It is important to note that despite all the information we know about space, it is very difficult to travel in space as it is HUGE and feels endless. Space is so big that even travelling very fast, it would take a long time to get anywhere. For example, it takes 3 days to get to the Moon at a speed of 35 000 to 40 000 km/h, and would take months to get to Mars. This is why Artemis II was such an impressive mission: space travel is extremely challenging, yet scientists and astronauts continue to make it happen.

Why Study Space?

Learning more about space is helpful as it supports the research and development of new technologies that improve daily life on Earth, such as advanced communications. For instance, some of the objects we use in our day to day, such as GPS, and weather forecasting, were created using information gained from studying space. Studying space helps us understand our planet, fuels scientific discovery, inspires future generations to pursue careers in STEM, and supports the long-term survival of humanity.

Tonight, when you look up at the sky, try spotting the Moon and/or the brightest star. All the objects you see are real things that are far, far away from us. These are also the same places that astronauts travel to.

Final Notes

Learning about the night sky is a starting point for learning astronomy more deeply about astronomy. The night sky consists of millions of objects, including the Moon, stars, planets, galaxies-- and it’s always expanding and growing! Looking up at the sky can help transform abstract concepts into visible, personal experiences.

So, the next time you look up at the night sky, remember: you are looking into space, filled with thousands of explorable objects! A question that always comes up is what are the little, shiny dots we see - they’re stars! Look out for the next blog about stars!

Written By: Krisha L