                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                 2021 July 8

                           Perihelion to Aphelion
                 Image Credit & Copyright: Richard Jaworski

   Explanation: Aphelion for 2021 occurred on July 5th. That's the point
   in Earth's elliptical orbit when it is farthest from the Sun. Of
   course, the distance from the Sun doesn't determine the seasons. Those
   are governed by the tilt of Earth's axis of rotation, so July is still
   summer in the north and winter in the southern hemisphere. But it does
   mean that on July 5 the Sun was at its smallest apparent size when
   viewed from planet Earth. This composite neatly compares two pictures
   of the Sun, both taken with the same telescope and camera. The left
   half was captured close to the date of the 2021 perihelion (January 2),
   the closest point in Earth's orbit. The right was recorded just before
   the aphelion in 2021. Otherwise difficult to notice, the change in the
   Sun's apparent diameter between perihelion and aphelion amounts to a
   little over 3 percent.

                     Tomorrow's picture: pixels in space
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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