ESA astronaut Sophie Adenot films intense aurora from space

A view of a dynamic aurora

On day 139 of the εpsilon mission, ESA astronaut Sophie Adenot published a short timelapse clip showing a striking green, wavy auroral band over the night side of Earth. The band contracts, expands and changes its structure. The vivid green is typical of oxygen emissions in the upper atmosphere. The video is set to music.

How auroras form

Charged particles from the solar wind are deflected by Earth's magnetic field and guided along field lines into polar latitudes. In the upper atmosphere they excite oxygen and nitrogen atoms, which emit light as they return to their ground state. Oxygen emissions often appear green, while nitrogen processes can produce red or purple hues. During strong solar activity the energy input increases, making the aurora brighter and more dynamic.

Why recordings from space are important

Satellite and ISS perspectives reveal the spatial extent and fine structure of auroras across large distances. From orbit, patterns and developments are easier to discern than from the ground, where weather and limited visibility can hinder observations. Timelapse sequences capture temporal changes with high density. Such data help test magnetosphere models and improve understanding of the energy balance in the upper atmosphere.

Significance for spaceflight and satellite operations

Auroral events heat the thermosphere and can cause it to expand. That increases atmospheric drag on satellites in low Earth orbit and affects orbit calculations, collision avoidance and fuel planning. Disturbances in the ionosphere impair radio communications and the accuracy of navigation signals. Radiation exposure for crewed missions can increase. Observations like these support verification of space weather events and adaptation of operational procedures.

Open research questions

Auroras reflect an exchange of energy that triggers local temperature and density changes in the upper atmosphere. Researchers investigate, among other things, changes in trace gases, chemical reaction chains and the coupling between upper and lower atmospheric layers. These processes have little direct effect on the climate of the lower atmosphere but can influence measurements and instruments used for climate data.

Public impact

Images from space make complex physics-based processes tangible and bring attention to topics such as space weather and satellite safety. For space agencies, such footage is a means of communicating the benefits of missions.

Technique and methodology

Capturing intense auroras requires adapted exposure times and sensitive sensors to reveal fine structures. Combined with measurements of charged particles and magnetic fields, a more complete picture of the event sequence emerges. Comparative analyses across multiple missions and platforms provide clues about patterns in solar activity and the magnetosphere's response.

Outlook

With more observations from Earth orbit, predictive models for space weather can be further refined. That increases operational safety for satellites and crewed missions — and at the same time opens accessible new insights into a striking natural phenomenon.