Oxygen Has Been Directly Detected in Venus Dayside Atmosphere

In a groundbreaking discovery, astronomers studying Venus have directly identified atomic oxygen in the planet daytime atmosphere, a revelation that sheds light on the intricate dynamics of the Venusian atmosphere and its circulation patterns. While atomic oxygen had been previously detected on Venus nightside, this new daytime observation offers valuable insights, according to physicist Heinz-Wilhelm Hübers and his team from the German Aerospace Center.

Venus, often dubbed Earth twin due to similarities in mass and composition, presents a stark contrast with its inhospitable environment. Shrouded in thick clouds primarily composed of carbon dioxide, Venus experiences extreme surface temperatures of around 464 degrees Celsius, accompanied by acid rain showers. The planet atmosphere exhibits rapid rotation, with winds reaching speeds exceeding 700 kilometers per hour—far surpassing Earth highest recorded wind speed.

Scientists are intrigued by the stark differences between Venus and Earth, and delving into the mysteries of Venus could potentially unravel the evolutionary paths of these two neighboring planets. Questions about whether Venus diverged from a similar trajectory as Earth or was inherently different from the outset linger.

Exploring the Venusian atmosphere, particularly through the study of atomic oxygen, offers a pathway to understanding the distinctions between Venus and Earth. Unlike the molecular oxygen we breathe (O2), atomic oxygen consists of lone oxygen atoms and is highly reactive, bonding easily with other atoms. On Earth, atomic oxygen is abundant at high altitudes, generated through the photodissociation of molecular oxygen.

Similar processes are thought to occur on Venus, where sunlight triggers the photodissociation of carbon dioxide molecules, yielding atomic oxygen and carbon monoxide. As these atoms migrate to Venus nightside, they recombine into carbon dioxide, causing the planet to glow. The unique aspect of the recent discovery is the direct observation of atomic oxygen on the dayside of Venus.

The research, conducted using data collected by the Stratospheric Observatory for Infrared Astronomy (SOFIA), revealed atomic oxygen at 17 locations on Venus—seven on the dayside, nine on the nightside, and one at the terminator. Concentrations peaked at an altitude of approximately 100 kilometers, situated between two dominant atmospheric circulation patterns on Venus.

This newfound insight positions atomic oxygen as an untapped resource for investigating the transitional zone in Venus atmosphere. The researchers anticipate that future observations, especially near specific points on Venus, will provide a more detailed understanding of this peculiar region and support upcoming space missions to the planet.

In the broader context of planetary atmospheres, comparing measurements of atomic oxygen in Earth and Mars atmospheres with those of Venus could contribute to enhancing our understanding of the divergent atmospheric compositions of these celestial bodies. The exploration of Venus, with its unique atmospheric characteristics, holds the promise of unlocking valuable clues about the evolution and divergence of planetary atmospheres within our solar system.