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Why can we see the stars but not all the planets?
- Alec (age 12)
We can see many stars but not ones that are too far away. Not enough light from them reaches us to see, even with a big telescope. The same pattern applies for planets- we can see ones nearby but not ones far away. Since planets are too cold to give off light on their own, they're much harder to see than stars. Even with telescopes, we can only see ones that are in our own solar system or unusually large ones around nearby stars. So we end up able to see many more stars than planets, because each star gives off a lot of light.
(published on 04/24/11)
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