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.
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.
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.”
I enjoyed seeing and hearing Clyde Tombaugh in 1990 talk about his discovery of Pluto. So I was a little disappointed when Pluto was demoted to minor planet status. Are there any minor planets known to have 5 moons? Also, I got into Astronomy in 1985 with the headlines of Comet Halley. Comets hold a special interest to me. I am still hoping that Panstaars L4 shines at magnitude -3 but I see that there is a new Panstaars for 2014. Looks like this one might get to Magnitude 5 perhaps. But all I know is that it will favor the South Hemisphere. I have been unable to find an ephemeris for it at brightest. I would appreciate if you could post one or tell me where I might find one.
Hi Edward,
No other minor planet we know of has five moons but there are a bunch with at least two moons. Here’s a current list:
http://www.johnstonsarchive.net/astro/asteroidmoons.html
To create an ephemeris for C/2011 L4 PANSTARRS, you can use the JPL Horizons website. http://ssd.jpl.nasa.gov/horizons.cgi?s_time=1#top