Fill in the Blanks Space explorationOnline version Complete the sentence by Greys Narvaez 1 alien plants lif Animals or that might live on other planets are called 2 sistem eight solar Our has planet s 3 Gravity fall makes things dow n 4 explore Neptune The planet was ed in 1846 . People didn't know it existed before that tim e 5 word world Another for planet is " " 6 about The distance from the earth to the sun is 150 kilometer s