7 important space firsts, including the little-known ones

They were not dogs and not even chimps. They were fruit flies! The insects left the Earth's atmosphere aboard a US V-2 rocket and were safely returned to the ground.

This small object, only 23 inches (58 cm) wide, orbited around Earth and marked the start of the legendary space race.

Two female dogs, Belka and Strelka, were lifted into orbit aboard Vostok, a new Soviet spacecraft. After a 24-hour journey, they returned home. Strelka later gave birth to six puppies, one of which was presented to Jacqueline Kennedy.

If you love learning new things about the Universe, distant galaxies and planets, you will easily ace this fun trivia quiz about space.

This 108-minute mission changed the world forever. A 27-year-old Soviet pilot Yuri Gagarin became the first cosmonaut in history. He orbited Earth and safely returned home. Unfortunately, 7 years after his iconic spaceflight, Gagarin met an untimely death. He and his co-pilot were killed in a training jet crash.

Did you know? The International Day of Human Space Flight is celebrated annually on April 12. In the Post-Soviet states, the celebration is still named Cosmonautics Day. An observance known as Yuri's Night was started in the US in 2001 on the same day.

The crew of the Apollo 8 spacecraft became the first people to see our planet as a whole. They were also the first astronauts to orbit around the Moon and see its 'dark side.' During the mission, William Anders took one of the most legendary space photographs of all time – Earthrise.

See 'Earthrise' and other beautiful space photos by NASA here.

Neil Armstrong became the first human to set foot on Earth's natural satellite. He was followed by the lunar module pilot Buzz Aldrin. While Armstrong and Aldrin were carrying out experiments on the Moon for 3 hours, Michael Collins stayed in the spacecraft. An estimated 600 million people worldwide watched the event live.

The exploration of Mars became earlier than many think – only 7 years after the first moonwalk. Viking 1 successfully touched down on the red planet and sent the pictures of its surface to Earth.