八下Module-2--Unit-2-They-have-seen-the-PyramidsVIP专享VIP免费

earth moonspaceshipastronautspace travelScientists have sent spaceship to Mars. The journey has taken several months. Astronauts have already been to the moon.No one has been to Mars yet, because Mars is very far away, much farther than the moon.Lots of scientists are working hard in order to send astronauts to Mars one day.Scientists think that there has been life on the Earth for hundreds of millions of years. However, we have not found life on any other plants yet.The Earth is a plant and it goes around the sun. Seven other planets also go around the sun. None of them has an environment like that of the earth, so scientists do not think they will find life on them. The sun and its planets are called the solar system, and our solar system is a small part of a much larger group of stars and planets, called the Galaxy or the Milky Way. There are billions of stars in the Galaxy, and our sun is only one of them. Scientists have also discovered many other galaxies in the universe. They are very far away and their light has to travel for many years to reach us. So how large is the universe? It is impossible to imagine.Scientists have sent spaceship to the planet Mars to take photos. They have even sent spaceships to travel outside the solar system. However, no spaceship has travelled far enough to reach other stars in our Galaxy.Look at the picture and talk about what you know about Chinese spaceships.Shenzhou-9 is a manned spaceship.Read the passage and choose the best title for it. 1. Anyone out there? 2. Life on the earth 3. The sun and other stars 4. The stars at night √ 1. The earth is a star. 2. The sun is a star.3. There is more than one galaxy in the univer...