The European Space Agency’s (ESA) ExoMars Trace Gas Orbiter (TGO) has detected for the first time a soft green glow in the night sky of Mars, visible to the naked eye. This phenomenon could become a natural guide for future explorers, illuminating the polar regions during the Martian night.
Nightglow, in which the atmosphere experiences weak light emissions that prevent the night sky from completely darkening, is a well-known phenomenon also observed on Earth; It is even a relatively common phenomenon in the atmospheres of the Solar System, such as on Mars, where it was expected, but had only been seen in the “daylight” of the planet on two occasions.
“These observations are unexpected and interesting for future trips to the red planet,” says planetary scientist Jean-Claude Gérard, from the University of Liège (Belgium).
Night glow on Mars
According to experts, this phenomenon occurs when oxygen molecules separate under sunlight, travel to the dark side of Mars and join again, generating electrons that cause the green glow about 50 kilometers above the planet’s surface.
Recognized under the term “airglow,” these emissions share similarities with the “auroras” we witness on Earth when energized particles from the Sun interact with our atmosphere.
However, despite this similarity, the main distinction between airglow and auroras is that the latter exhibit notable variations in terms of space and time, while airglow is characterized by its uniformity, as explained in detail the ESA blog.
Nightglow is a valuable “tracer of atmospheric processes”
The discovery, documented in the journal Nature Astronomy, has surprised the scientific community and offers new perspectives for future missions to the red planet. In addition, it sheds light on the composition and dynamics of the Martian atmosphere, providing valuable data on oxygen density and the interaction between sunlight and the solar wind.
According to Universe Today, These findings strengthen the similarities between Mars and Earth, highlighting connections in their compositions and atmospheric processes. The information collected could also be crucial to understanding why some worlds are conducive to life, while others adopt different fates.
As various space agencies plan future manned missions to Mars, these in-depth investigations are expected to unravel more secrets about the Red Planet’s past and possibly offer clues to the current or past existence of life on Mars.
Time.news Interview: Unveiling the Martian Nightglow
Editor (E): Welcome to Time.news! Today we have the pleasure of speaking with Dr. Jean-Claude Gérard, a renowned planetary scientist from the University of Liège in Belgium. Dr. Gérard, thank you for joining us and sharing your insights about this remarkable discovery regarding Mars.
Dr. Gérard (G): Thank you for having me! It’s a pleasure to discuss such exciting developments in space exploration.
E: Let’s dive right in. The European Space Agency’s ExoMars Trace Gas Orbiter detected a soft green glow in Mars’ night sky for the first time. Could you explain what this “nightglow” is and what caused this phenomenon?
G: Absolutely! Nightglow, or “airglow,” occurs when certain molecules in the atmosphere—primarily oxygen—separate under sunlight, travel to the darker side of the planet, and then recombine. As they do so, they emit light that creates this soft glow, visible about 50 kilometers above the Martian surface. It’s fascinating because it means that even in darkness, there’s a consistent light source in the atmosphere of Mars.
E: That’s incredible! On Earth, we typically associate glowing phenomena with auroras. What’s the difference between auroras and this airglow we see on Mars?
G: Great question! While both auroras and airglow involve light emissions in the atmosphere, they operate quite differently. Auroras are dynamic and can vary significantly, depending on solar activity like solar winds interacting with our magnetic field. In contrast, airglow is a more uniform phenomenon, providing a constant and steady light rather than sudden bursts of brightness.
E: So, this discovery could have practical implications for future Mars missions, correct?
G: Exactly! The soft green glow could serve as a natural guide for future explorers, especially in the polar regions where darkness can be particularly challenging. It can help illuminate the landscape and assist in navigation during the Martian night.
E: That’s fascinating and could truly transform how we approach Mars exploration. How was this phenomenon expected by scientists before this discovery, and why was it only observed in daylight previously?
G: Scientists have long theorized about airglow on Mars, yet it had only been detected in the daytime due to the brightness of the sun overpowering the weaker emissions during the night. Observing the glow at night was unexpected, which is why this detection is so thrilling—it validates our models of Martian atmosphere behavior while also offering new opportunities for research.
E: Speaking of research, what does this discovery mean for our understanding of Earth’s atmosphere in comparison to that of Mars?
G: By studying the similarities and differences between Martian nightglow and phenomena seen on Earth, we can gain deeper insights into atmospheric chemistry and dynamics across different planets. This could enhance our knowledge related to habitability and environmental conditions, both on Earth and beyond.
E: Looking ahead, how might this discovery influence other space missions, perhaps even those aimed at human colonization of Mars?
G: This finding could be crucial for planning future missions. The visibility of glowing regions might inform landing sites and operational planning for long-duration stays. Also, understanding atmospheric behavior like this is key to developing life-support systems for human occupants.
E: Thank you, Dr. Gérard! It’s clear that the discovery of nightglow on Mars opens up new avenues for exploration and understanding of our neighboring planet. We appreciate your insights and look forward to seeing what the future holds for Mars exploration.
G: Thank you! I’m excited to see how these discoveries will shape our future missions and potentially answer many questions about habiting Mars.
E: And thank you to our readers for joining us today. Stay tuned for more updates on space exploration and scientific discoveries!