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Solar day and sidereal day

  1. Oct 8, 2008 #1
    I know that a solar day is about 4 minutes longer than a sidereal day.

    But what if the earth orbital period around the sun is halved, but the rotation period is same?

    Will the solar day still be about 4 minutes longer?

  2. jcsd
  3. Oct 8, 2008 #2


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    The 4minutes is to account for the distance accross the sky the sun moves in a day.
    So it takes 23:56 min for the earth to rotate but then you have to move another 4mins to catch up with the sun which has moved on a bit.
    If the earht moved twice as fast around the sun, the sun would have moved twice as far and so you would need (roughly) an extra 8 minutes to catch up and a solar day would 24:04.
  4. Oct 8, 2008 #3
    this makes sense, thanks.
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