Greetings stargazers.
The current sunspot cycle maximum continues to amaze. Several times during the past year, the Aurora Borealis has been visible in the Durango sky. It was here again a couple of weeks ago, but I could only see this one with my camera, and it wasn’t dancing around as much as the spectacular events last year.
This week there has been a very large sunspot group near the center of the solar disk. This group, that is many times the diameter of Earth, has already emitted several X-class flares, which are the most energetic type. These solar flares are emissions of high energy electromagnetic radiation that can easily interfere with terrestrial communications. The other event that is possible with such an active solar region is the emissions of energetic charged particles. It is these particles from what are called coronal mass ejections that really play havoc with our magnetosphere and put on the auroral light shows.
When coronal mass ejections hit the Earth’s magnetic field, the field gets squished. Charged particles that would normally hit the upper atmosphere at very high latitudes end up hitting much farther south than they normally would. The red color seen most in Durango is from oxygen atoms in the upper atmosphere being hit and excited. Other colors, mostly seen much farther north, are from other spectral lines of oxygen and nitrogen, the two most common elements in our atmosphere.
An interesting aside about our magnetic field deals with which end is north. When undisturbed, the Earth’s magnetic field looks like one produced by a simple bar magnet. Counterintuitively, if you had to label the poles of this Earth magnet, you would need to put a south label in the Arctic and a north label in the Antarctic. This is because the ends of a bar magnet like the one in a compass are defined by which geographic direction they point. The one we define as “north” points toward our north geographic pole. As you are probably aware, opposite magnetic poles attract, and like magnetic poles repel, which means the pole that will attract what we have labeled “north” must be one labeled “south.”
Useful links
Unfortunately, there is no more snow this month than there was this time in January. I trust I am not alone in being willing to trade several nights of stargazing for some overnight heavy snowfall. Photo memories are showing up for me from February 2019 when the snow was so high in our front yard we couldn’t see over the edge of the driveway. This year all I am seeing is brown – and even some green – grass.
During months when the moon is crossing the ecliptic, there is occasionally the chance for both a lunar and a solar eclipse two weeks apart. This is one of those months, but you would need to travel to Antarctica to see the annular (ringlike) solar eclipse Feb. 17. The total lunar eclipse will be on the morning of March 3. It should be visible in the western sky just before sunrise.
Jupiter was at opposition last month, so it is in an ideal place to view this month. The four Galilean moons should be visible through most binoculars. Because of all the clear nights, a fun exercise might be to repeat the observations of Galileo by drawing the locations of the moons from one night to the next. There are often noticeable differences in the moons’ locations even between early and late evening observations.
Charles Hakes teaches in the physics and engineering department at Fort Lewis College and is the director of the Fort Lewis Observatory. He can be reached at hakes_c@fortlewis.edu.
