Some 50 to 400 miles above the surface of the Earth lies a tumultuous “sea of electrically charged ions and electrons” that envelops our planet. This is the ionosphere — the mysterious frontier that connects the Earth and outer space.
This particular region of the space environment is notoriously difficult to study, since it’s too low for satellites to observe and too high for scientific balloons to reach. Nevertheless, the ionosphere contains a wealth of data that directly influence our planet and our society.
As the threshold between Earth’s atmosphere and space, the ionosphere is subject to influences from both worlds. This area is under continuous turmoil as a result of terrestrial weather; at the same time, the ionosphere is also ceaselessly pummeled with solar radiation. Therefore, it is constantly swirling with electrically charged gasses, solar wind, and magnetic fields.
“Neither fully Earth nor space, the ionosphere reacts both to winds and weather from the lower atmosphere below and solar energy streaming in from above, changing constantly to form conditions we call space weather,” explains NASA.
The perpetual changes occurring within the ionosphere can have a deep impact on our technology, disrupting GPS signals and affecting our satellites. In addition, turbulences in the ionosphere can also have a negative effect on the astronauts living and working in space.
To study the physics of this environment, NASA is launching an ionospheric mission dubbed ICON, which is scheduled to take to space in the early hours of tomorrow morning.
Early in the morning of Nov. 7, 2018, NASA launches the Ionospheric Connection Explorer, or ICON, a spacecraft that will explore the dynamic region where Earth meets space: the ionosphere. https://t.co/Kz0XJ5ONeW pic.twitter.com/g6HxZdlx70
— NASA Goddard (@NASAGoddard) November 6, 2018
Short for the Ionospheric Connection Explorer, the ICON spacecraft will be investigating the connection between terrestrial weather and space weather, as reflected in the changes that take place in the ionosphere.
The spacecraft is set to blast off into space at 3:00 a.m. EST on November 7. ICON will soar to the heavens atop a Northrop Grumman Pegasus XL rocket, traveling inside a Stargazer L-1011 aircraft. The Stargazer will ferry the Pegasus at a height of roughly 40,000 feet, releasing the rocket about five minutes into the journey.
After a five-second free-fall, the Pegasus will turn on its engines and fly the ICON spacecraft to low-Earth orbit, deploying it approximately 11 minutes after the separation from the Stargazer.
“The Ionospheric Connection Explorer will study the frontier of space: the dynamic zone high in our atmosphere where terrestrial weather from below meets space weather above,” NASA states in the mission overview.
In order to do that, the ICON mission is tasked primarily with monitoring the glow of Earth’s upper atmosphere, also known as airglow. According to the space agency, airglow “refers to the light that shines from the ionosphere, enveloping Earth in a tenuous bubble of red, green, and yellow.”
This phenomenon is created by the luminous emissions of electrically charged gas — the same process that produces auroras. However, unlike the spectacular northern and southern lights observed by star gazers at extreme latitudes, airglow shines all around the planet and is considerably fainter.
— NASA Sun & Space (@NASASun) November 6, 2018
“It’s amazing that our atmosphere glows like this, but what’s more — it gives us a direct ability to make observations of the key parameters we need in order to investigate the connection between the neutral atmosphere and the ionosphere,” said Thomas Immel, ICON principal investigator at the University of California, Berkeley. “I can’t wait to see what airglow looks like from ICON’s point of view.”
Aside from helping scientists get a clearer picture of what goes on in the ionosphere, Earth’s airglow can reveal precious details about our planet’s atmosphere. Since different atmospheric gases glow in certain colors and at specific altitudes, studying the kaleidoscope of Earth’s natural glow can shed new light on the make-up of our atmosphere, its density, and its temperature.
The ICON launch will be livestreamed on NASA Television, with coverage of the event beginning as early as 2:45 a.m. EST.