Utah Skies: March's Full Moon

Mar 31, 2021

March’s Full Moon is known as the Worm Moon in the Traditional Farmer’s Almanac. It was believed that this is the time of year that the earthworms appear as the soil starts to warm up.

Some ancient astronomers believed the dark areas of the moon were bodies of water and therefore named them seas and even oceans. We now know that these areas are lava fields. There was volcanic activity over a billion years ago in these areas. The volcanic material has a higher iron concentration than the material in the highlands. This material is less reflective and looks darker. We also know that the volcanic activity resulted more recently than the creation of the Moon, because there are fewer craters in these areas. It is believed that the volcanic material covered over the older craters.

To find the seas on March 30, 2021, look for the terminator line, where the sun-lighted area meets the dark shadow, on the upper right side of the moon. In this area, you may be able to make out the Sea of Fertility and the Sea of Crisis. Continuing to the left is the Sea of Tranquility where Apollo landed in 1969. Next is the Sea of Serenity, and then the Sea of Rains. 

In the bright highlands, you will find Tyco, the most famous crater on the Moon. It is near the bottom right in the brightest region. Tyco is very bright and has long lines radiating from the crater. Some of these lines are over 600 miles long. Tyco is named after the Danish Astronomer Tyco Brahe.

After the bright moon rises most other deep sky objects are difficult to see or even find. However, the Moon itself can be fascinating to study. It can be seen visually, with binoculars, or telescopes. Because it is so bright, lunar filters for telescopes are recommended. NASA has maps of the moon on the internet that are amazing. Some show the names of the craters. Wikipedia has a list of the names for the craters on the Moon. Near the landing site of Apollo 11 there is a crater named after Neil Armstrong, 4.2 km in diameter. Another is named after Buzz Aldrin, 2.8 km in diameter.

It is also interesting to watch the moon as it goes through its different phases. The best area to see definition between objects is to look at the Terminator, the line between the light and dark sides of the moon. Here the shadows help to give a better idea of the height of the mountains or crater walls. There are always more things to see on the Moon.