What are 5 interesting facts about space? There is so much about space, our solar system, and the galaxy that we still don’t know! Space is vast. With billions of galaxies and stars, and planets in our own solar system yet to be fully explored or understood, scientists’ knowledge of space is always evolving. There are, however, some really cool things we know about space right now! We’ve compiled a list of what we think are five stellar facts that we hope you’ll think are out of this world! 1. SPACE IS COMPLETELY SILENT There is no atmosphere in space, which means that sound has no medium or way to travel to be heard. 2. THE HOTTEST PLANET IN OUR SOLAR SYSTEM IS 450° C. Venus is the hottest planet in the solar system and has an average surface temperature of around 450° C. Did you know that Venus isn’t the closest planet to the sun? That is Mercury. You would think that Mercury would then be the hottest, but Mercury has no atmosphere (which regulates temperature), resulting in big fluctuations. 3. A FULL NASA SPACE SUIT COSTS $12,000,000. While the entire suit costs a cool $12m, 70% of that cost is for the backpack and control module. However, the space suits that NASA uses were built in 1974. 4. THE SUN’S MASS TAKES UP 99.86% OF THE SOLAR SYSTEM. The Sun accounts for 99.86% of the mass in our solar system with a mass of around 330,000 times that of Earth. Did you know that the Sun is made up of mostly hydrogen (three-quarters worth) with the rest of its mass attributed to helium? If the Sun had a voice would it be high and squeaky from all that helium? 5. ONE MILLION PILES OF EARTH CAN FIT INSIDE THE SUNThe Sun is large enough that approximately 1.3 million Earths could fit inside (if squashed in) or if the Earths retained their spherical shape then 960,000 would fit. But can you visualize that number of Earths?