Solar Magnetic Field About to Change

This is not “new” news, since it was announced earlier this year, but the Sun’s magnetic field is about to flip its polarity sometime in the next few weeks to a month. When this happens, the Sun’s polar magnetic fields weaken and then drop to zero.  Shortly thereafter, they emerge again, but with the opposite polarity. So, if one pole was “north”, it will be “south” after the flip, and the other will flip to “north”. This is really an outward effect of the Sun’s interior dynamo reorienting itself. This is a regular part of the solar cycle. The Sun does this every 11 years, regular as clockwork. Completely normal and nothing to be worried about.

It’s not completely clear yet WHY the Sun’s north pole flips south and the south pole flips north, although solar physicists are making great strides in understanding actions inside our star that cause this and other activity. They DO know that the new polarity builds up throughout the 11-year-long sunspot cycle. Sunspots are those dark spots that appear on the visible surface of the Sun. They’re regions where the temperatures are cooler than the surrounding surface and thus they appear darker. Astronomers at Stanford University, who are monitoring this regular magnetic field flip, described the process in a press story released last month.

“New polarity builds up throughout the 11-year solar cycle as sunspots – areas of intense magnetic activity – appear as dark blotches near the equator of the sun’s surface. Over the course of about a month, sunspots disintegrate, and gradually that magnetic field migrates from the equator to one of the sun’s poles.

As the surviving polarity moves toward the pole, it erodes the existing, opposite polarity, said Todd Hoeksema, a solar physicist at Stanford since 1978 and director of the Wilcox Solar Observatory. The magnetic field gradually reduces toward zero, and then rebounds with the opposite polarity.

“It’s kind of like a tide coming in or going out,” Hoeksema said. “Each little wave brings a little more water in, and eventually you get to the full reversal.”

When the Sun’s polarity flips, it does actually affect the rest of the solar system, but not in any psychic or alien way. And yes, there ARE people out there who interpret a magnetic field flip as some kind of paranormal thing. Nothing could be further from the truth, which is that the Sun is an active, evolving, magnetized sphere of plasma, and as such, it has constantly changing characteristics in ALL its magnetic fields. It has an overall magnetic field, and it also has localized magnetic fields which cluster around sunspots and are suspected to be involved in heating of the corona in some way. So, if you start to see hysterical ravings about the “mysterious” magnetic field flips of the Sun and how it will bring on a new age of psychic unity or something unlikely, put on your skeptic hat and turn to actual solar science for some answers.

Actually, the effects of a solar magnetic field flip are pretty cool to study. The changes propagate out to the “edge” of the heliosphere (the limit of the Sun’s influence in space).  Since these flips coincide with higher sunspot activity and more bursts of charged particles (through flares and coronal mass ejections), we can expect to see more auroral displays. The interactions with Earth’s magnetic field can affect our technology (how much it does so depends on the severity of any space weather “attack” fostered by the Sun’s activity), and might cause satellite operators to put their instruments into “safe mode” for a short while. We are currently in the middle of “solar max”, which is supposed to be the maximum amount of activity during a sunspot cycle. This has been a somewhat quiet solar max, so it will be interesting to see how the magnetic field reversal plays out.

If you want to read a more detailed description of what happens during a polarity flip, check out the Science Daily article from August 6th of this year or the recent press release from Stanford University, whose Wilcox Solar Observatory has been watching the Sun since the mid 1970s and is providing very good long-range looks at the Sun’s activity.

A Successful Lunar Landing

I’ve been on travel the past three weeks, speaking about astronomy on board a cruise ship. I get a lot of questions from my fellow passengers, and usually somebody asks me when we’ll go back to the Moon. Well, folks, “we” in the form of the Chinese space agency, have returned to the Moon this week. Not necessarily a crew of humans walking around, but a spectacularly beautiful mission called Chang’e-3 and its Yutu rover.

If you haven’t checked out the mission, it’s part of the Chinese Lunar Exploration mission, designed to explore the lunar surface, and eventually bring back samples for study. If this sounds familiar, the Apollo missions did similar studies in the 1970s, but no one has been back to the Moon to continue those studies. The Chinese missions are taking up where the U.S. left off and I expect they will take lunar studies to the next level very soon. I wish them much luck — the exploration of the Moon, or that of any solar system object, is a complex task and requires the best and brightest to accomplish it. It also requires national and political will to see the positive opportunities in extending our scientific understanding beyond the surface of our home world.

The study of the Moon and other objects in the solar system is an increasingly multi-national process. Doing such exploration is expensive, and individual countries such as India, Japan, and China are making their mark in planetary science. But, in the future, I suspect that many missions will continue to be conducted by collaborations of scientists from many countries, such as with the Cassini Mission to Saturn. Not only was NASA involved, but the European Space Agency provided Huygens lander for Titan exploration, and scientists from 17 countries participate in science acquisition and data analysis. The Chinese and Russians have explored joint collaboration for future lunar missions, and there are many other joint projects between various countries under consideration.

While the Chinese bask in the glory of achievement, and received laudatory comments from many of us in the U.S. (including a nice set of comments by my good friend Greg Redfern (the SkyGuy)) I’ve noticed (and unfortunately expected) a tide of whining from some people in the U.S. (not all of us, mind you), about how it’s the Chinese going to the Moon now. We should be congratulating our fellow humans on their brilliant work, not pissing and moaning about it. I’m not sure what to say to the whinging contingent except, “Stop complaining and do something. Support NASA, support science research in our country, support science education, and if your representative in Congress or your Senator don’t support these things, let them know that they are undermining our future. Find new ones who will take us forward, not hold us back. If you don’t take action at your level, you’re part of the problem.”

You know, we once had a forward-looking space policy in the U.S., and it has been undermined. The laundry list of those who seek to gut our future is long, and it stretches from the halls of government to the apathetic voters who don’t give a damn. That’s all got to change. Otherwise, we’ll see more missions with “others” going where we in the U.S. thought we were going. There’s room in space for everybody, and the U.S. doesn’t have a monopoly on space travel. We certainly got it going, and it inspired many people to look to the skies for technological achievements. That’s great. I think it’s great that other humans on our home planet are taking to the skies. I hope sincerely that in the U.S. our best days are still ahead of us.  But, we need to make it happen. Just as the Chinese and Indians and Europeans and Iranians and Japanese have done.