Supermoon brightens night sky: A lesson in orbital mechanics

Published Nov. 16, 2016
By Airman 1st Class Dennis Hoffman

PETERSON AIR FORCE BASE, Colo. -- The moon is a steady sight in the great Colorado sky, brightening dark nights and reminding Airmen of the importance of the wing mission, but an extra “super” supermoon flew closer to Earth than previously recorded in 68 years on Nov. 14.

There won’t be another supermoon like this past one until 2034, said the National Aeronautics and Space Administration.

The moon’s orbit around Earth is elliptical, making its orbit sometimes closer and sometimes farther away. When the moon is full and makes its closest pass to Earth, it is known as a supermoon.

At perigee, the point at which the moon is closest to Earth, the moon can be as much as 14 percent closer to Earth than at apogee, the farthest point in orbit from our planet. The full moon appeared much larger in diameter and because it was larger, the moon bounced 30 percent more light onto the Earth, said NASA.

The moon was at perigee at 6:22 a.m. Eastern Standard Time Nov. 14, and “opposite” the sun for the full moon at 8:52 a.m. EST.

This was the second of three supermoons in a row during 2016. If the clouds didn’t cooperate, Airmen will have another chance next month to see the last supermoon of 2016 on Dec. 14.

NASA scientists have studied the moon for decades. A better understanding of our moon helps scientists infer what is happening on other planets and objects in the solar system.

“The moon is the Rosetta Stone by which we understand the rest of the solar system,” said Noah Petro, NASA Lunar Reconnaissance Orbiter mission deputy project scientist.

LRO has been mapping the moon’s surface and capturing high resolution images for more than seven years. Extensive mapping of the moon aids scientists in understanding our planet’s history, as well as that of planetary objects beyond our solar system and satellites affected by the Earth-moon relationship, said NASA.

Along with the studies from NASA, Peterson AFB uses the moon as a teaching tool to educate space operators on the orbital mechanics of our satellites and the debris floating around the planet, while also being an influence in satellite creation.

“All of our satellites are built with the idea that the moon will tug on them,” said Maj. Joshua Johnson, Reserve National Security Space Institute deputy division chief. “We factor the little bit of gravity that will pull on them into the way we build our satellites and how we plan to maneuver patterns, so the supermoon is not going to change anything significant in our operations.”

Without an understanding of orbital mechanics and a general knowledge of the Earth-moon relationship, backyard astronomers might not know the best nights for moon-gazing are predictable. The predictability of the moon’s orbit is similar to the man-made satellites’ orbits which Peterson AFB tracks, making the mission more precise and manageable.

“Orbits are fixed in space,” said Rails Ryals, Advanced Space Operations School senior space and cyber instructor. “There are some changes or perturbation that can happen to the orbits, but they are very predictable. As the satellites are approaching our radar sites, our radars know where the satellites have been in the past so they know where to look for in that pass, and same goes with the moon.”

The 21st Space Wing operates ground-based sensors, which includes radars and telescopes, for space situational awareness. Space surveillance is a critical element of the space control mission and relies on orbital mechanics and other tracking mechanisms for assured access to space.