Did Aliens Already Know that Earth Has Intelligent Life? Astronomers Investigate

Intan Rakhmayanti Dewi, CNBC Indonesia

Tech

Monday, 06/11/2023 19:50 WIB

Photo: Participants wearing spacesuits and alien-themed costumes during the Area 51 ‘storm’. (REUTERS / Jim Urquhart)

Jakarta, CNBC Indonesia – Astronomers believe that aliens already know that there is human life on Earth. The reason is that human activity, intentionally or not, has left many signs of intelligent civilization.

To date, according to the BBC, humans have discovered more than 5,500 planets in the same galaxy as Earth. Astronomers estimate that there are still trillions of planets outside the Milky Way galaxy.

But until now, researchers on Earth have not found evidence of intelligent life on other planets in space.

The ways astronomers search for aliens vary, from monitoring chemical signals in the atmosphere to scanning technological signals such as radio waves.

If aliens on other planets used the same methods as humans on Earth, they should have known long ago that there was intelligent life on Earth.

Signs of life on Earth have long spread throughout the galaxy. In fact, the signal spread more intensely and widely in the 1900s until the World War II era.

“[Mereka dari zaman Perang Dunia] needed a stronger signal because the radios used by people at that time did not have sensitive radio antennas,” said Howard Isaacson from UC Berkeley, quoted from Futurismon Monday (6/11/2023).

Even now, radio waves still radiate to and from all corners of the Earth in the form of cellular signals to television, although they are more difficult to detect.

“Radio stations are certainly not intended to send signals into space, but to the Earth’s surface,” said Thomas Beatty of the University of Wisconsin.

Humans have also flown a number of probes to all corners of the Solar System, even further into other regions of space. Each spacecraft is equipped with its own wave transmission.

According to Isaacson, the Voyager mission will send signals to at least more than 1,000 stars by 2030. “The signals received will clearly appear to be artificial signals,” he told the BBC.

Isaacson added that aliens living around the nearest star to Earth will have time to receive and send a response signal in the next 8 years.

Not just radio waves. Observers from other planets can also guess that there is life on Earth by observing the Earth’s atmosphere. Lights that emit sodium can also be a sign of advanced civilization.

According to Paul Rimmer, an astrochemist from the University of Cambridge, the best indicators of life on Earth are oxygen, nitrogen and water vapor. “All three are indications of the ocean [di Bumi] contains a stable fluid.”

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