The quietest sun in a century

What is wrong with the sun? Oh, it isn't going to blow up or anything like that, at least not for a few billion years. What I am referring to is there have been no sunspots, what is being called a deep solar minimum.

The sun has sunspot cycles that normally last for 11 years. Going from one peak of sunspot activity down to a minimum then back up to an active sunspot season. We are in a minimum period now.

But this is not just any ordinary sunspot minimum. Typically during a minimum period we get at least a few sunspots, but the observers who study such things, like Dean Pesnell of the Goddard Space Flight Center, have remarked just how deep this solar minimum is. In a report issued by Science@NASA he says, "We're experiencing a very deep solar minimum."

David Hathaway of the Marshall Space Flight Center is quoted in the same report saying, "This is the quietest sun we've seen in almost a century."

In the 366 days of 2008 observers reported a spotless Sun on 266 days. 2009 is starting off even quieter: as of the end of March, 78 of the year's 90 days saw a blank solar disk. To find a blanker sun you would have to go back in the records to 1913 which had 311 spotless days.

Sunspots are giant, often planet-sized areas of intense magnetism on the surface of the sun. They are the source of solar flares, coronal mass ejections -- massive amounts of charged particles hurled into space from the surface of the sun. When these particles strike Earth's atmosphere, they can cause extensive displays of Aurora Borealis or Aurora Australis -- the Northern and Southern Lights.

Hathaway adds, "Since the Space Age began in the 1950s, solar activity has been generally high. Five of the 10 most intense solar cycles on record have occurred in the last 50 years. We are just not used to this kind of deep calm."

This shouldn't be too much to worry about though, the deep calms in 1901 and 1913 were even longer than the current one and observers believe this one could even last another year.

So, what does all this mean for us?

Well, for one thing the atmosphere won't be heated quite as much and won't expand and exert a drag on all of the satellites orbiting us which means they won't be dragged into lower orbits or possibly out of orbit. We will also have to wait a little longer to observe any spectacular Northern Lights show.

SKY WATCH:

Third quarter moon on April 17. The conjunction of the moon and Saturn on April 6 was not as spectacular of some of the recent Mars/moon parings, but was interesting to observe. One conjunction you don't want to miss will occur on Sunday, April 19, about an hour before sunrise. Look in the southeast for a very slender crescent moon right up next to the bright planet Jupiter. Keep looking to Jupiter's left with your binoculars for the relatively dim Neptune. All should be in the same binocular field of view. The really exciting conjunction will occur on Wednesday morning, April 22. Look in the east just above the horizon for that same crescent moon you saw a few days earlier. Only this time it will be a lot thinner and very, very close to bright Venus. In fact, (and you will need a telescope for this) if you keep watching the pair, the moon will occult, or pass in front of Venus. This event will happen after sunrise, which is why a telescope will be needed to observe it. Almost directly below the moon/Venus pair you will find Mars trying to shine through the atmospheric haze. If you look almost level to the right of the moon a dim Uranus will be visible. The whole group should be in the same binocular field of view, although you may have to move it around a little to see all of them.

NEXT TIME:

More astronomical blathering.