He has now moved to the Stratospheric Observatory for Infrared Astronomy (SOFIA) to make the first measurement of oxygen heavy atoms in Earth’s upper atmosphere.
Heavy metal is so named because it has 10 neutrons, instead of the normal eight for the “primary” oxygen that we breathe. Heavy pain is considered a sign of biological activity, common in the lower atmosphere. Both forms are a byproduct of photosynthesis, but the sum of the oxygen from the respiration of living things consumes more than the rest, leaving a higher concentration of heavy metals.
But little is known about how this supply of heavy oxygen penetrates from the place of its creation, near the earth, to the highest regions of the atmosphere. Through its high spectral resolution, the SOFIA LARGE instrument has measured the main ratio of heavy oxygen in the mesosphere and lower thermosphere, marking the first spectroscopic detection of heavy oxygen outside the laboratory.
“The path of biological activity is proven,” Helmut Wiesemeyer, a scientist at the Max Planck Institute for Radio Astronomy, says in a statement. “Until now, it was thought that the height to which this signature extends was 60 kilometers – so like the bottom of the mesosphere – and it was asked, does it reach higher altitudes? There, the only way to reach higher altitudes would be efficient vertical mixing.”
In other words, the only explanation for the large concentrations of severe pain in these regions is the movement of the air up and down, which may have important implications for climate change.
Measuring oxygen saturation is complex because it is very similar to primary pain. From high in the stratosphere, SOFIA was able to separate the two elements against the lunar background: the brightness of the Moon allowed maximum sensitivity in distinguishing these properties.
This allowed the researchers to measure the ratio between primary and heavy oxygen up to 200 kilometers into the atmosphere. The results -published in the Physical Review Review ranged from a diversity of 382 to 468 factors in the two types of oxygen, similar to the terrestrial system.
“There are processes that change these proportions. On Earth, this process is oxygenic life,” says Wiesemeyer, although other possible chemical explanations should also be considered.
Wiesemeyer and his collaborators were very conservative in their uncertain views, so they cannot fully attribute their most important measurements of oxygen to biology. The solar wind, for example, may bring heavy oxygen to Earth, but its contribution is unlikely to be that great.
This pilot study of measuring the balance between the two forms of oxygen is proving a technique that atmospheric scientists could use to study vertical mixing. The results of the study may also help to better define the biologically relevant boundary of the Earth’s atmosphere.
More ambitiously, future instruments sensitive to various oxygen signals could use similar techniques to measure oxygen levels in exoplanets. The combination of elevated oxygen abundance with an understanding of vertical mixing on these exoplanets could indicate biological activity – although the group’s assurances of such a study would require massive sensitivity that current technology does not have.
“You have to first understand what’s going on at your doorstep before you delve deeper into studies elsewhere,” Wiesemeyer said.
These observations are too low even for low-orbit satellites, but too faint to be made from the ground. Observations from stratospheric balloons could provide possible future studies.
The SOFIA space observatory was a joint project of NASA and the German Space Agency (DLR). The plane is maintained and operated by NASA in Palmdale, California. SOFIA reached full operational capability in 2014 and completed its last scientific flight on September 29, 2022.