1. What is space?

Answer: Space is the vast, seemingly infinite expanse beyond Earth’s atmosphere, where stars, planets, moons, and galaxies exist.

2. What is the universe?

Answer: The universe is everything that exists, including all matter, energy, galaxies, stars, planets, and space-time itself.

3. How big is the universe?

Answer: The universe is estimated to be 93 billion light-years in diameter, and it continues to expand.

4. What is a light-year?

Answer: A light-year is the distance that light travels in one year, approximately 5.88 trillion miles (9.46 trillion kilometers).

5. What is dark matter?

Answer: Dark matter is an unknown form of matter that does not emit light or energy, but it is believed to make up about 27% of the universe’s mass.