The annular solar eclipse in New Mexico
On Saturday, Oct. 14, 2023, a solar eclipse will traverse New Mexico, crossing Albuquerque and Roswell. This is not a total solar eclipse though, which happens when the Sun is completed obscured. It will be an annular solar eclipse.
A solar eclipse happens when the Sun, the Earth, and the Moon align. The Moon is about 400 times smaller than the Sun, but it is also 400 times closer to us. By this sheer coincidence, they appear with almost the same size in the sky, and the Moon can block the entirety of the face of the Sun. But not all eclipses are born equal. The Moon’s orbit is elliptic, so its distance from the Earth varies. When the moon is at the point in its orbit that is furthest from Earth, it looks smaller than the Sun. If an eclipse happens when the Moon is at this distance, even if perfectly aligned, a ring of light around the edge of the Sun will still be visible.
That’s what will happen on Oct. 14. About 6% of the surface of the Sun will still be visible. Sounds like not much left, but the Sun is very bright: 6% of it is still a lot of light. Yet, annular eclipses are still a sight to behold. Many of the characteristics of a solar eclipse are still in place. You will be able to notice the day darkening, and the temperature falling as the Sun passes from waxing to waning. A few minutes from maximum, you may feel you need a jacket, as the temperature may drop by up to 20 degrees while the Moon blocks the sunlight that warms our planet. Besides not having the minutes of darkness and viewing the Sun’s corona, an annular eclipse is still an out-wordly experience without leaving the planet.
Annular eclipses are also a reminder of the distant past, and the far future to come. Every year, the Moon moves about 2 inches away from the Earth. We can then conclude that the Moon was much closer to the Earth in the past, so much so that it appeared much larger than the Sun, and annular eclipses were not possible. Every eclipse was either total or partial. Annular eclipses only started to be possible about a billion years ago. This also means that one distant day, the Moon will be too far to completely cover the Sun, and all eclipses will be annular. That day is also about a billion years in the future, so there’s no need to feel nostalgia for total eclipses just yet!
The Astronomy Department at NMSU is planning a few activities in advance, open to the public. At Las Cruces the eclipse will not be annular, but only partial, meaning the Sun will be seen as a waning crescent. The Sunspot Solar Observatory will have events the whole day along. There will be eclipse viewing opportunities for people, with zoomed-in view from the telescope projected on multiple screens. They will open to the public the observation room of the Dunn Solar Telescope and, in partnership with the Lowell Observatory, they will livestream the event in their YouTube channel, where the public will be able to talk to scientist from both observatories. On-site will be a better treat though, with the Triple Nickell BBQ Food Truck serving food. The Observatory opens at 8 a.m. The eclipse begins at 9:14 a.m., the maximum will be at 10:39 a.m. ending at 12:13 p.m.
In Las Cruces, in collaboration with the Las Cruces Museum of Nature and Science and the Thomas Branigan Memorial Library, NMSU will host an eclipse viewing at the Aggie Memorial Stadium, starting around 9 a.m. going till roughly noon.
In the path of maximum annularity, in Artesia, NMSU astronomers will be at the Artesia Science center, where they will perform experiments on scientific balloons to study the effects of a solar eclipse on Earth's atmosphere. They have also prepared cool activities for elementary and high school students.
As the day approaches, the excitement in New Mexico builds, to share in this awe-inspiring experience. Astronomers are calibrating their instruments, and enthusiasts are marking their calendars for the 14 of October. As the moon casts its shadow, we are reminded of our place in the vastness of the Universe, and that the beauty of the cosmos continues to captivate us all. So, on that Saturday morning, let us come together under the New Mexico skies and celebrate the wonder of the annular solar eclipse, a sight that connects us to the past, present, and distant future.
Wladimir Lyra is an associate professor of astronomy at New Mexico State University. He can be reached at @LyraKstellation (twitter) or wlyra@nmsu.edu (email).
This article originally appeared on Las Cruces Sun-News: The annular solar eclipse in New Mexico
