Astronaut Jessica Meir photographs purple aurora from space with a Nikon Z9

NASA astronaut Jessica Meir photographed a green and purple aurora over Kyrgyzstan from the International Space Station. For the capture, she used a Nikon Z9 camera with a focal length of 15 mm. The image documents how solar particles excite atmospheric gases at different altitude layers during a moderate geomagnetic storm.

For ground-based photographers, this orbital perspective offers a visual lesson on the physics of night-sky light. It clearly demonstrates why aurora colors appear distinct when looking toward the zenith compared to viewing them in profile from low Earth orbit.

Atmospheric layer structure and origin of the purple glow

From Earth's surface, the observer looks upward through the entire atmospheric column. This perspective typically superimposes optical emissions, blending colors on the camera sensor. Green emission from atomic oxygen dominates between 100 and 200 kilometers in altitude, whereas nitrogen produces violet and blue hues at higher altitudes.

When photographed from the space station at an altitude of over 400 kilometers, the camera captures the phenomenon in cross-section. The composition reveals a compressed green ribbon hugging the curvature of the planet, crowned by standalone purple rays reaching into space. The camera used is an off-the-shelf Nikon body without physical modifications. The unit operates with custom firmware designed to optimize thermal noise, file naming protocols, and power management in the orbital environment.

Equinox alignment and recommendations for astrophotography

The solar disturbance that created this display was classified as a G1 geomagnetic storm, the baseline tier on NOAA's space weather scale. The spectacle was amplified by proximity to the equinox. Around the equinoxes, the Russell-McPherron effect aligns Earth's magnetic dipole with interplanetary magnetic fields, promoting stronger coupling with the solar wind.

In addition to the single exposure, the astronaut captured 30-second long-exposure sequences through the Dragon spacecraft windows. These stacked sequences blend the diffuse aurora glow with star trails, orbital satellite tracks, and city lights across Central Asia.

In practice, ground astrophotographers can leverage equinox periods to schedule dark-sky sessions at middle and high latitudes. When the Kp index reaches 5, purple rarely manifests as a standalone curtain. From the ground, it typically appears as a faint upper fringe on green auroras due to atmospheric line-of-sight integration.