Astronomy Picture of the Day

   [1]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.

                               2025 January 4
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                            Welcome to Perihelion
    Image Credit & [3]Copyright: Peter Ward ([4]Barden Ridge Observatory)

   Explanation: [5]Earth's orbit around the Sun is not a circle, it's an
   ellipse. The point along its elliptical orbit where our fair planet is
   closest to the Sun is called perihelion. This year perihelion is today,
   January 4, at 13:28 UTC, with the Earth about 147 million kilometers
   from the Sun. [6]For comparison, at aphelion on last July 3 Earth was
   at its farthest distance from the Sun, some 152 million kilometers
   away. But distance from the Sun doesn't determine Earth's seasons. It's
   only by coincidence that the beginning of southern summer (northern
   winter) on the December [7]solstice - when this [8]H-alpha picture of
   the active Sun was taken - is within 14 days of Earth's perihelion
   date. And it's only by coincidence that Earth's perihelion date is
   within 11 days of the historic perihelion of NASA's [9]Parker Solar
   Probe. Launched in 2018, the Parker Solar Probe flew within 6.2 million
   kilometers of the Sun's surface on 2024 December 24, breaking its own
   record for closest perihelion for a [10]spacecraft from planet Earth.

                      Tomorrow's picture: rocket launch
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    Authors & editors: [22]Robert Nemiroff ([23]MTU) & [24]Jerry Bonnell
                                 ([25]UMCP)
          NASA Official: Amber Straughn [26]Specific rights apply.
              [27]NASA Web Privacy Policy and Important Notices
                A service of: [28]ASD at [29]NASA / [30]GSFC,
                         [31]NASA Science Activation
                           & [32]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2501/20242112SolNeg.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. http://www.atscope.com.au/BRO/bardenridgeobs.html
   5. https://earthsky.org/tonight/earth-comes-closest-to-sun-every-year-in-early-january/
   6. https://www.timeanddate.com/astronomy/perihelion-aphelion-solstice.html
   7. https://apod.nasa.gov/apod/ap241221.html
   8. https://www.atscope.com.au/BRO/gallery699.html
   9. https://science.nasa.gov/mission/parker-solar-probe/
  10. https://blogs.nasa.gov/parkersolarprobe/
  11. https://apod.nasa.gov/apod/ap250103.html
  12. https://apod.nasa.gov/apod/archivepix.html
  13. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  14. https://apod.nasa.gov/apod/lib/aptree.html
  15. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  16. https://apod.nasa.gov/apod/calendar/allyears.html
  17. https://apod.nasa.gov/apod.rss
  18. https://apod.nasa.gov/apod/lib/edlinks.html
  19. https://apod.nasa.gov/apod/lib/about_apod.html
  20. http://asterisk.apod.com/discuss_apod.php?date=250104
  21. https://apod.nasa.gov/apod/ap250105.html
  22. http://www.phy.mtu.edu/faculty/Nemiroff.html
  23. http://www.phy.mtu.edu/
  24. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  25. http://www.astro.umd.edu/
  26. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  27. https://www.nasa.gov/about/highlights/HP_Privacy.html
  28. https://astrophysics.gsfc.nasa.gov/
  29. https://www.nasa.gov/
  30. https://www.nasa.gov/centers/goddard/
  31. https://science.nasa.gov/learners
  32. http://www.mtu.edu/