March 10, 2007
Astronomy Note for March 2007
Sorry we are late with the March note, but this is another sedate month for amateur skywatching. But it is an interesting month for solar system events.
There was a lunar eclipse on 3 March, coinciding with the Full Moon known as the Crow Moon by some plains indian tribes, the Sap Moon in New England, and Lenten Moon in parts of Europe. Unfortunately, only the last half of this eclipse would have been visible if you were in New England, and less anywhere else in the states. But here it is anyway, photographed by Tunc Tezel in Antalya, Turkey, and posted on Spaceweather.com. Tunc took this series of photos through an 8 inch reflector, which is why the moon appears to be moving the wrong direction.
The moon has just crossed northward over the earth-sun orbital plane, so this is offically eclipse season. Sure enough, there will be a partial eclipse of the Sun on 19 March, up to 88%, but
you'll have to be in Mongolia to see it.
The Moon also just passed Apogee, or the point in its orbit furthest from Earth (about 64 earth radii, on 7 March.
Venus shines brightly in the evening sky, setting 3 hours after sunset. It is about 80% full. (Remember that planets closer to the Sun than us show phases, like the moon.)
Saturn is high in the ESE sky, and has good views of its rings through modest telescopes.
Jupiter rises at about midnight. The Earth, the Sun, and Jupiter form a right angle this month, which means that Jupiter's shadow appears long and to the west. How would you see this shadow? The shadow will frequently be eclipsing Jupiter's moons. Several of these moons are visible in binoculars, and they will pop into the sunlight like car headlights being turned on.
Best viewing is near dawn, when air is still.
Mars is appearing about 90 minutes before dawn in the morning sky.
Mercury is appearing less than 60 minutes before dawn in the morning sky.
Meteor showers are very minimal this month. A shower called the Virginids runs from 25 Jan through 15 April, with several modest peaks. Previous observations hint that there might be a peak in early March-but even that coincides with the full moon. A shower called the gamma Normids peaks around 14 March. Just in case you need a reminder where to find constellation Norma, it's southwest of Scorpio and below the horizon. So scratch that from your March list, too.
In case your name is Caesar, the Ides of March is 15 March. The Vernal Equinox is 21 March (at 5:09 pm Flagstaff time, the Sun crosses the ecliptic into the northern hemisphere.)
Since there is so little else to talk about in this March, let me mention that 2007 is the 23rd Sunspot "minima". In the 11-year sunspot cycle, this is the low point, approaching zero sunspots. 23rd refers to the fact that this is the 23rd cycle since the first peak was recorded in 1761.
This doesn't mean no solar activity! There is one sunspot now, number 946. But a large flare has just blasted through a coronal hole, and a solar stream should hit earth on the 11th of March, creating an Aurora display over Alaska and Scandinavia.