Earth’s distance from the sun varies because its orbit is an ellipse or oval with the sun slightly off to one side. When closest, our planet is at perihelion; when farthest, aphelion. As distance varies, so does Earth’s speed. Illustration: Bob King

Yesterday July 4 Earth reached aphelion (AP-hee-lee-un) or its farthest point from the sun this year. The difference between closest and farthest points in our orbit amounts to about 3 million miles. How I wish that would translate into cooler temperatures. Not gonna happen. While 3 million sounds like a big number, our orbit is so big we’re only about 3% farther today compared to perihelion in January.

Aphelion also occurs during the year’s warmest season, so any slight effects introduced by a closer, bigger sun are lost in summer’s heat. You be tempted to think that in the southern hemisphere, where it’s now winter, the extra distance would add a extra shiver to the air, but the vast expanse of southern oceans moderate the temperature.

Sunspot region 1515 at 11:30 a.m. (CDT) today photographed with NASA’s Solar Dynamics Observatory. The group harbors the potential for the most powerful variety of flares called X-class. Credit: NASA

The sun has been trying to kick up a storm all the same. Sunspot region 1515, which has grown to more than 8 times Earth’s diameter, is now easily visible with the naked eye through a safe solar filter. If you bought one for the Venus transit, dust it off and give the sun a look today. The spot group is located to the lower right of the sun’s center and look like a small piece of “dirt” on the otherwise smooth disk.  1515 has been going bananas with M-class flares (big, high-energy variety); sky watchers in the northern U.S., northern Europe and Canada should be watchful for northern lights starting tomorrow night July 6 through the morning hours of July 7.

Check your local listing for tonight’s PBS show on light pollution titled “The City Dark”. Credit: Wicked Delicate Films LLC

Tonight PBS will air a POV documentary on the growth of artificial light and the effects of light pollution on the skies, our psyche and our health. Titled “The City Dark” you can watch it in Duluth, Minn. on Channel 8 starting at 9 p.m. Click HERE to check your local schedule.

While many of us love “the city lights”, we sometimes forget the price we pay in the loss of the night sky. Comfortable in our cocoons of light, we’re blinded to the stars and a visceral connection to the cosmos. Many city dwellers have no idea what constellations look like let alone the Milky Way.

Astrophysicist and director of New York’s Hayden Planetarium Neil deGrasse Tyson said it best: “When you look at the night sky, you realize how small we are within the cosmos. It’s kind of a resetting of your ego. To deny yourself of that state of mind, either willingly or unwittingly, is to not live to the full extent of what it is to be human.”