1、m3journey to spaceunit 2 we have not found life on any other planets yet.pre-reading: revision of u1:do you remember the latest news in unit1?while-readingscientists think that there has been life on the earth for hundreds of millions of years. however, we have not found life on any other planets ye

2、t.the earth is a planet and it goes around the sun. seven other planets also goaround the sun, none ofthem has an environment like that of the earth, soscientists do not thinkthey will findlife on them. the sun and its planets arecalled the solar system, and our solar system is a small part of a muc

3、h 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 many years to reach us. so how

4、 large is the universe? it is impossible to imagine.scientists have sent spaceships to theplanet mars to take photos. they haveeven sent spaceships to travel outside the solar system. however , no spaceship hastravelledfar enough toreach otherstars in our galaxy.scientists have always asked the ques

5、tions : with so many stars in the universe,are we alone, or is there lifeout there in space? have there been visitors to theearth fromother planets ?why has no one communicated with us? w do notknow the answer yet.read and draw a mind map about the universe？ in which paragraph？the main idea and the

6、question about parp.2 : why isn t any life onethother planets?the main idea and the question about parp.3: where are the other galaxies?the main idea and the question about parp.4: where have the scientists sent spaceships to?the main idea of parp.1:the main idea and the question about parp.5: what questions have they asked?what does the last sentence mean?especially the“” .get the main idea of the passage,choose the best answer1.anyone out there ?2.life o