4 February 2023
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NASA’s Space Geodesy Project

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NASA explains why 30 June received an extra ‘leap second’

30 June 2015 Astronomy Now

Although we are unaware of it in our everyday lives, the Earth’s rotation is slowing down, so each mean solar day is about 0.002 seconds longer than the last. NASA explains why Tuesday, 30 June 2015, will have an extra second, or “leap” second, added.

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News Headlines

  • See all the planets in January
    16 January 2023
  • Frank Drake, SETI pioneer, 1930–2022
    3 September 2022
  • Webb images of Jupiter show auroras, rings, moons
    24 August 2022
  • Webb: Stellar nursery in Carina
    12 July 2022
  • Webb: a ringside seat to galactic mergers and interactions
    12 July 2022
  • Home
  • The Magazine
    • About
    • Current Issue
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      • January last issue
      • February last issue
      • March last issue
  • AstroFest 2023
  • News
  • Observing
    • UK Sky Chart
    • Almanac
    • Scope Calc
    • DSLR Calc
  • Reviews
    • Equipment
    • Book Reviews
  • Spaceflight Now
  • Shop
  • Contact Us
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