Before the 20th century there were no galaxies! Of course there were galaxies, but nobody had recognised that many misty nebulae were awesome wheels of billions of stars. Only in the early 20th century did Hubble establish that these objects were at massive distances beyond our galaxy.
So, are we to keep calling these galaxies, nebulae, just for nostalgic reasons? Nebulae are simply clouds of gas or dust in space, and the word nebula means cloud, which is what galaxies look like until you throw more magnification at them.
So, why isn't everybody up in arms about the status change for galaxies.
Animals and plants are reclassified all the time, as scientists realise that they have been grouping them wrongly.
So, since astronomers first discovered that planets weren't just wandering stars, they have had the right to say what is a planet and what isn't.
In the light of new information, Pluto cannot be classified as a planet.
2006-08-24
16:59:47
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4 answers
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asked by
nick s
6