This is a bit out of date. Perhaps children won't mind. Pluto is no longer a planet. Plans for humans to go to Mars have been scrapped. The Very Large Telescope in Chile was completed years ago. Etc.

It says there is no proof that UFO's exist when clearly objects that haven't been identified do exist, there's just no proof they are space aliens.

But, nevertheless probably a fun book for kids who like science.

The kids realy like the animations and presentations of this book. While it is definately not boring, the planets themselves get only one page each of factual info in super small text. The solar system overview chapter was great for group reading and was primarily what I used from the book, including a photo of a meteorite in comparison to the size of children. Translation: great as a fun addition to learning but not to replace hard fact texts and in-depth lesson plans.
----You don't need to read the accompanying Magic Tree House fiction book in order to use this research guide.

My kids love these research guide books from Magic Tree House writers but this one was a disappointment. One whole chapter was devoted to the big bang theory which we personally don't believe in. They should have skipped this chapter and focused on facts.

Once you are 100 miles above Earth, you are in space. Anything beyond Earth's atmosphere is space. There are a lot of planets, stars, and space rocks in space.
A spacecraft travels in space and carries supplies and people. A spacecraft has to go 25,000 miles per hour to get away from gravity and get into space. Spacecrafts have rockets to lift them into space.
Fuel is burning in the rocket at very hot temperatures. The hot gasses come out from the bottom and push the rocket up. Rockets were used 1,000 years ago as fireworks and weapons by the Chinese.
The Soviet Union and the Unites States had a race to have a spacecraft go into space. The Soviet Union sent the first satellite into space. A satellite is something that travels around a planet. The Soviet Union won that race. The United States put its own satellite into space and the race began.
An astronaut is a person from America that is trained to go into space. A cosmonaut is a person from Russia trained to go into space. A person from Russia, or a cosmonaut, orbited the Earth in less than two hours. He was the first person to orbit the Earth.
The United States and the Soviet Union had a race to get someone into space first. John F. Kennedy made a challenge to send someone to the moon before the 1960's were over. A lot of people worked for that goal.