The IAU, which is the official arbiter of astronomical names, chose single names to refer to those stars that have historically had many. Some of the decisions may rattle longtime observers, however. For example, the binary star Alpha Centauri, which lies 4.35 light-years from the sun, is n...
1.阅读理解 (4.0) 分 In this passage the words “closest to our sun” means the star ___ . A、the earth we live on B、Alpha Centauri C、the Big Dipper D、the moon2.阅读理解 (4.0) 分A one-way journey to Alcaid would take ___ . A、about nine years...
How these laser-propelled robots could bring us to a star 25 trillion miles awayDarren WeaverKevin Loria
If one traveled at the speed of light, he could make a round trip to Alpha Centauri in nine years. But, even at that speed, he could not reach Alcaid (北斗星)in the handle of the Big Dipper. A one-way journey to Alcaid would take almost 200 years. A. the earth we live on B...