Weather Blog

July 12, 2008|By FRANK ROYLANCE | FRANK ROYLANCE,Sun Reporter -- Weather Blogger

Bob Walsh, in Baltimore, wonders about the summer solstice. Usually it is June 21, but it was June 20 this year, for the first time since 1896. It can occur on June 22, but not again until 2203. "What causes the date/time to change?" Bob asks. Our 365/366-day calendar year doesn't perfectly match the "tropical year" - the time it takes Earth to return to the same spot in its journey around the sun. Mostly, that orbit varies because of gravitational tugs from Jupiter and other planets.

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