Bob Berwyn isn't our fav astronomer guy. Professor Jimmy Westlake, over on Steamboat Today is our absolutely best fav 'star man'.
But...Berwyn does put out some good posts on what's happening in the galaxy. This one is quite interesting.
"SUMMIT COUNTY — It may not be quite as sexy as the recent lunar eclipse, or as spectacular as this morning’s meteor shower, but Earth nonetheless experiences another celestial milestone today when it reaches it’s closest point to the sun during its 365-day orbit.
To be precise, at perihelion, our planet will close in to within about 91 million miles of the sun, more than 3 million miles closer than at the early July aphelion, when the the Earth and sun are more than 94 million miles apart. All this because, of course, the Earth’s orbit is elliptical and not circular.
It may seem counter-intuitive that the Earth is closer to the sun during the coldest time of the year, but the temperatures at the surface of the planet are influenced by the 23.5 degree tilt of the Earth’s axis and the angle of the sun’s rays much more than by the distance from the sun. Because of that tilt, the northern hemisphere days are much shorter in our winter, leading to the colder temperatures.
According to NASA, there are measurable differences in solar heating that result from our planet’s slightly elliptical orbit.
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