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What is there highly developed life on earth before humans? Researchers are looking for clues

Would it be possible that in the course of the 4.5 billion-year history of our planet, a highly developed civilization already populated the earth long before humans? What sounds like science fiction like “Star Trek” or a “Doctor Who” episode is actually being studied by scientists.

Adam Frank, professor of physics and astronomy at the University of Rochester, and Gavin Schmidt, director of the Nasa Goddard Institute for Space Studies, want to find out whether there were other civilizations millions of years before humans.

Signs in the rock and sediment

Based on the well-known sci-fi series “Dr. Who "is what the two scientists call their work, which they recently published in the" International Journal of Astrobiology ", as the" Silurian hypothesis ". In the popular TV series, the Silurians portray highly developed creatures that populated the earth about 400 million years ago.

Frank and Schmidt want to investigate whether the possible existence of unknown intelligent life from primeval times in rocks and sediments can be traced. This hypothesis could provide new approaches in the search for extraterrestrial life, the researchers believe.

Which traces will tell us in millions of years

The two scientists use the present as a point of reference. Based on the geological sequence, the history of the earth is classified into different ages. We are currently living in the New Earth Era within the “Holocene” epoch, which began 11,700 years ago. However, the influence that humans have on the earth is so great that some researchers argue for the introduction of a new age called the Anthropocene. Loosely translated, the Anthropocene means a man-made age.

It is true that in millions of years our remains, cities and buildings will have turned to dust. In addition, the earth is not as densely populated as it seems to us. Any intact artifacts that testify to our existence would therefore have to be discovered first.

But the massive encroachment on the environment that we have made since the Industrial Revolution will leave its mark on the earth's history for a long time to come. Through agricultural use and the clearing of forests, we trigger severe soil erosion, which may be geologically detectable for a long time to come.

Immortalized by the ecological footprint

Our high plastic production worldwide could lead to a layer of plastic forming on the ocean floor and staying there for a long time. In addition, there is our high consumption of fossil fuels, which has an impact on the natural carbon cycle.

The researchers Schmidt and Frank suspect that earlier civilizations millions of years ago, just like modern humans, could have left an ecological footprint, the traces of which could be found in the rock and sediment.

New approaches for alien researchers

Similar markers have not yet been found in any geological studies. In the history of the earth, however, there are events such as primeval global warming, the causes of which researchers cannot explain: around 56 million years ago there was a climate change that has parallels to today. Even then, global warming was accompanied by an increase in greenhouse gases. An increased amount of CO2 in the atmosphere also acidified the oceans.

To what extent this prehistoric global warming may have been influenced by intelligent living beings remains pure speculation. "Gavin and I have not yet found any evidence of a highly developed civilization before modern man," Adam Frank writes in a press release. However, there is no evidence to disprove the existence of intelligent life.

The assumption of the two researchers is speculative. But their hypothesis could provide new approaches for the search for extraterrestrial life. "We know that the living conditions on Mars and Venus were more favorable a long time ago than they are now," said Schmidt in an interview with "IFLScience". “It is conceivable that one day we could drill sediments on strange planets. Then we would at least know what traces in the rock we would have to look for. "