There is so much about space, the solar system, and galaxies that we still don't know! Large space. With billions of galaxies and stars, and planets in our solar system still unexplored or fully understood, scientists' knowledge of space is constantly evolving. Even so, there are some really cool things we know about space right now! We've compiled a list of what we think are ten-star facts that we hope will make you optimistic as you step out of this world! 

1. SPACE IS COMPLETELY PURE:  There is no atmosphere in space, which means the sound has no medium or path to be heard. 

2. THE HOTTEST PLAN IN OUR SOLAR SYSTEM IS At 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 is the hottest planet in the Solar System? Is the planet closest to the sun? This is Mercury. You would think that Mercury would be the hottest, but Mercury has no atmosphere (which regulates temperature), which leads to large fluctuations. 

3. A COMPLETELY GOOD NASA SPACE SUIT COST $12,000,000: While the entire suit costs $12 million, 70% of that cost is for the backpack and control module. However, the spacesuits used by NASA were built-in 1974. If valued at today's prices, they would cost around $150 million! 

4. MASS OF THE SUN REPRESENTS 99.86% OF THE SOLAR SYSTEM:  The Sun is 99.86% of the mass of the Solar system with about 330,000 times the mass of the Earth. Did you know that the Sun is composed mainly of hydrogen (3/4) with the rest of its mass being helium? If the Sun had a voice, wouldn't it be squeaking and squeaking from all that helium? 

5. MILLION EARTHS CAN FIT THE SUN:  The Sun is big enough that about 1.3 million Earths could fit inside it (if crushed) or if the Earths remained in their spheres then 960,000 can stick to it. But can you imagine that number of Earths? 

6. THERE ARE MORE PLANTS ON EARTH THAN STARS IN MILKY WAY: There are about three trillion trees on planet Earth, and between 100 and 400 billion stars in the galaxy. 

7. SUNSET IN MARCH APPEARS BLUE: Just as colors are made more dramatic in sunsets on Earth, sunsets on Mars will, according to NASA, appear bluish to human observers from the Red Planet. Fine dust makes the blue color near the Sun's sky easier to see, while normal daylight makes the familiar rusty dust color of the red planet most noticeable to the human eye.