Astronomers Discover Unusual Green Glow on Mars for the First Time
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Chapter 1: Introduction to Mars' Green Glow
Recently, the red planet has presented a surprising sight, one that may not be as unfavorable as it sounds. Scientists from the European Space Agency (ESA), utilizing the Trace Gas Orbiter (TGO), have captured an image of Mars exhibiting an unusual green glow in its upper atmosphere. This phenomenon, referred to as night glow, results from interactions between oxygen atoms and solar radiation. Observing this glow on Mars can enhance our understanding of various physical processes in the planet's atmosphere.
You may have encountered images or videos showcasing night glow, but typically not from Mars. Earth also displays a similar green hue in its atmosphere. Although night glow is challenging to observe from the ground, there are numerous captures from the International Space Station and satellites illustrating this ethereal green light. The mechanism behind night glow resembles that of auroras, such as the northern lights. Charged particles from the sun collide with atmospheric atoms, exciting them and causing them to emit light at specific wavelengths. In contrast to auroras, night glow is a consistent, subtle illumination that spreads across more extensive areas. Additionally, there is a daytime variant known as day glow, which is even more elusive.
Section 1.1: The Nature of Night Glow
Despite Mars lacking breathable oxygen, it is rich in oxygen atoms in the form of carbon dioxide. This recent observation marks the first instance of detecting night glow on any celestial body other than Earth. The ESA team suspected that, much like on Earth, the glow would only be visible when viewed edge-on. They positioned the satellite to scan between 12 miles and 250 miles (20 to 400 kilometers) above the Martian surface, and indeed, they observed the characteristic green glow of oxygen.
Section 1.2: Understanding Martian Atmospheric Dynamics
The research team developed models to gain deeper insights into the dynamics of the Martian atmosphere. They concluded that the glow likely originates from the decomposition of carbon dioxide in the upper atmosphere, releasing enough free oxygen to generate light. The TGO scrutinized the light from these atoms across the visual spectrum and ultraviolet light, revealing that the visible output was 16.5 times more intense than the ultraviolet emissions. Surprisingly, the night glow emissions observed on Mars are stronger than those on Earth, indicating that there is still much to learn regarding the behavior of oxygen atoms in extreme conditions.
Chapter 2: The Journey of the Trace Gas Orbiter
The Trace Gas Orbiter reached Mars in 2016 as a component of the ExoMars mission. Unfortunately, the Schiaparelli lander encountered issues during descent and crashed. The subsequent phase of ExoMars has been postponed, missing its 2020 launch window, but is now slated for a 2022 launch that will include a stationary lander and the Rosalind Franklin rover.
The first video details the James Webb Space Telescope's recent discovery of a planet exhibiting city lights located 7 trillion miles from Earth, providing a glimpse into the potential for extraterrestrial life.
The second video explains the findings of a new study regarding the mysterious green glow on Mars, clarifying that it is not an aurora as previously thought.