Why a ‘strong signal’ from space has got scientists very excited

In space institutes around the world, scientists dedicate their lives to looking for signs of life beyond our solar system. One year ago, the radio telescope RATAN-600, operated by Russian scientists in an area close to the border with Georgia, picked up an unusually large signal.

It’s thought to have come from a star called HD 164595, which is 6.3 billion years old and 95 light years away. It has at least one planet. Although the discovery does not prove the existence of alien life, it is interesting and “loud” enough to be worth investigating further. The Russian team recently announced their finding to the international community, urging others to help monitor the star.

Image: Centauri Dreams

The announcement sparked the interest of the Search for Extra-terrestrial Intelligence (SETI) Institute in California, which has 42 antennas that make up its Allen Telescope Array (ATA), all of which are designed to pick up alien communication.

SETI in fact picks up thousands of signals daily, and the first thing they had to decide is whether the Russian-found signal did indeed come from HD 164595. The institute agrees that it may well have come from the star, but warns that this “isn’t necessarily the case”.

In order for an alien civilization to send a signal to earth, says SETI, they would either need to send out a signal in all directions, hoping that another planet picks it up, or they would need to send it purposefully in our direction. In either scenario, the energy needed far exceeds anything we could manage here on Earth: over a trillion watts, which is comparable to the total energy consumption of all humankind.

If the signal were a blast-all type, the civilization sending it could be a Kardashev Type II. If it came directly to us, then the civilization would likely be Kardashev Type I, says SETI. We are at Kardashev 0.

Kardashev types are based on a scale created by Russian astrophysicist Nikolai Kardashev, and measure the technological advancement of a society based on how much energy it can harness.

Image: SETI

This isn’t the only signal to be detected, and to cause a flurry of excitement among the scientific community. Forty years ago, a signal nicknamed “WOW”, which fitted the profile of an alien transmission, was picked up by Ohio State University’s Big Ear radio telescope.

The signal never returned, however, and the event remains unexplained, although there is a current theory that the signal was connected to two passing comets.

More recently, scientists have been trying to figure out why the light dims on a star called KIC 8462852, with some surmising that it may be due to massive extraterrestrial construction.

SETI estimates that there are thousands of exoplanets that have so far been discovered, and that there are probably millions more in our galaxy. Given our distance to them, it is impossible to tell if they are habitable.

Since Russian scientists revealed the existence of the signal, SETI has been watching the sky. As yet, however, the signal has not been picked up again.

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