If we study the universe, we will discover significant facts about what's happening beyond our planet.
There are a lot of mysteries in the universe. It's important that we have a good understanding of the universe because Earth is polluted and we might need to move to another planet.
How big is the universe? What is it like inside a black hole? How did the world begin?
If we can answer these questions, we will learn the truth about our planet.
Try your best to discover more about the universe.
EUNICE CHEUNG HOI-CHING
Tsuen Wan Public Ho Chuen Yiu Memorial College
Thanks for your letter, Eunice. Learning about the universe is fascinating. It's amazing to think that there are astronauts now spending long periods of time living on the International Space Station.
Did you know that the United States space agency Nasa plans to build a permanently-occupied base on the moon? They say it will be a science station, as well as a place to test technologies needed for future travel to Mars. They plan to start building in the next 15 years.
The trouble with space exploration is that we are spreading our pollution wherever we go. Nasa has said that space is so full of rubbish - rocket parts, tools, plastic bags - that it has become a danger to astronauts and satellites.
Victoria, Assistant Editor