A Journey Taken by Solar System Millions of Years Ago Possibly Changed Earth's Climate Forever, Claim Researchers
The solar system is integral to humans because of its role as Earth's habitat. Decades of research have proven to astronomers that Earth in many ways is dependent on the conditions of the solar system. A recent study published in Astronomy & Astrophysics sheds light on one of how the solar system appears to have influenced Earth.
Researchers from the University of Vienna conducted the study. The team took into consideration data garnered from the European Space Agency's (ESA) Gaia mission as well as other spectroscopic observations and concluded that a particular passage undertaken by the solar system 14 million years ago possibly changed Earth's climate forever. This voyage was through the Radcliffe Wave in the Orion region.
Past examinations have confirmed that the Radcliffe Wave is a thin structure in space that hosts several interconnected star-forming regions. The team also determined the path undertaken by the sun in the Radcliffe wave through their analysis. "We passed through the Orion region as well-known star clusters like NGC 1977, NGC 1980, and NGC 1981 were forming," João Alves, professor of astrophysics at the University of Vienna and co-author of the study added, stated Phys.org. "This region is easily visible in the winter sky in the Northern Hemisphere and summer in the Southern Hemisphere. Look for the Orion constellation and the Orion Nebula (Messier 42)—our solar system came from that direction."
Experts think that this voyage compressed the planet's heliosphere (a protective bubble that surrounds Earth). The team believes this happened because of the Orion star-forming complex's density, the region through which the Solar System specifically traversed. "Imagine it like a ship sailing through varying conditions at sea," explained Efrem Maconi, lead author and doctoral student at the University of Vienna. "Our sun encountered a region of higher gas density as it passed through the Radcliffe Wave in the Orion constellation." As a result, there was a huge influx of interstellar dust in Earth's atmosphere. This possibly facilitated a huge impact on the planet's atmosphere, with its traces supposedly still visible in geological records.
According to scientists, this intergalactic dust may have left radioactive elements from supernovae in Earth's geological records. At present there is no technology to confirm this assertion, but experts are hopeful that future detectors will be able to make such a detection. The study claims that this passage took place somewhere between 18.2 and 11.5 million years ago. In this period Earth underwent the Middle Miocene Climate Transition, during which the planet moved from being warm to cold. This shift was so huge that it resulted in a continental-scale prototype Antarctic ice sheet configuration.
Despite the findings, the team is asking for more research to validate this claim. This is because, for both the past assertion of a long-term decrease in greenhouse gas concentration and the present claim of intergalactic dust inflation, the available data does not align with a lot of known factors.
"While the underlying processes responsible for the Middle Miocene Climate Transition are not entirely identified, the available reconstructions suggest that a long-term decrease in the atmospheric greenhouse gas carbon dioxide concentration is the most likely explanation, although large uncertainties exist," Maconi said. "However, our study highlights that interstellar dust related to the crossing of the Radcliffe Wave might have impacted Earth's climate and potentially played a role during this climate transition. To alter the Earth's climate the amount of extraterrestrial dust on Earth would need to be much bigger than what the data so far suggest." Hence further examinations will help scientists arrive at the right conclusion.