Astronomers are setting their sights on a new target in the search for extraterrestrial life: terraformed ‘Snowball Earths’.
These planets, which may have undergone deliberate climate manipulation, could provide unique opportunities to find signs of alien civilizations. The concept stems from Earth’s own history, when our planet experienced global ice ages known as “Snowball Earth” periods.
These frozen epochs, which occurred hundreds of millions of years ago, left the Earth’s surface completely or almost completely covered in ice. However, life persisted in refuges such as volcanic hotspots and areas of high geothermal activity, the report said forbes.com.
Scientists believe that if alien civilizations exist and have the technological prowess to terraform their planets, they might choose to transform these frozen worlds into habitable environments. This terraforming could potentially leave behind detectable signatures that we can observe from Earth.
The idea is to look for exoplanets that appear to have been artificially heated, leading to partial deglaciation. Detecting such changes would entail identifying unusual patterns in a planet’s climate or atmosphere that cannot easily be explained by natural processes alone.
For example, a planet with a significant portion of its ice cover mysteriously melted away could suggest the influence of advanced technology. These signs can be detected through various astronomical techniques, including the study of a planet’s atmospheric composition and surface temperatures.
The search for terraformed Snowball Earths represents an exciting frontier in the broader search for extraterrestrial life.
Traditionally, astronomers have focused on finding Earth-like planets in the habitable zones of their stars, where liquid water might naturally occur. However, this new approach broadens the scope to consider planets that may not naturally support life, but have been modified by intelligent beings to become habitable.
The study of terraformed snowball Earths is still in its early stages, but shows promise. This line of research is part of a growing field known as technosignature searches. Unlike biosignatures, which look for signs of life itself, technosignatures look for evidence of advanced technologies used by alien civilizations.
This includes everything from the air pollutants from industrial activity to large-scale construction such as Dyson bulbs.
