But within the next few years, astronomers expect to find dozens of alien earths that are roughly the size of our planet.

但是在接下来的几年内，天文学家期待着发现几十个在大小上大致类似于我们这颗行星的星外地球。

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And there are probably many alien Earths out there to be found in our Milky Way galaxy, researchers say.

MSN: Senior writer