Extra-terrestrial aliens probably don’t know about us!

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

26 April 2020

In February this year, scientists in Canada reported that they had detected a regular pattern of radio waves coming from deep outer space. According to their measurements, the signal was repeating itself every 16 days. The source was traced to a galaxy that lies some 500 million lightyears away. Could this be evidence of intelligent life elsewhere in the universe? Well, we will probably never know.

The reason is that 500 million years is a very long time. Human beings have existed on Earth for just 250,000 years. 500 million years ago, the most sophisticated living creature on this planet was something that looked like a jellyfish.

But, wait a minute: why am I talking about time when, in fact, the 500 million light years is a distance? It is because a lightyear is the distance light travels in one year. Therefore, the radio signal started its journey 500 million years ago.

Radio waves are similar to light; the only difference is that their frequency is much lower – as explained last week. They travel at the same speed as light: one billion kilometres per hour, or 9.5 trillion km per year.

Thus, when scientists report that the galaxy is 500 million lightyears away, what they are saying is that it is 4,730,400,000,000,000,000,000km – 4,730 billion-billion km. Quite a mouthful!

Now, assuming that evolution happens everywhere in the universe and that all celestial bodies face the same probability of a catastrophic events, it is most likely that whatever lifeform (if any) that sent out the radio signal no longer exists today!

You see; in the last 500 million years, there has been five extinction events on earth and they wiped out more than two-thirds of all lifeforms on the planet in each instance. Consequently, it is reasonable to expect that even in the galaxy 500 million lightyears away, something similar may have happened.

Hot on the heels of this story came another report that the most earth-like planet had been identified – Kepler 1649c. Obviously, it is not within our solar system. But, at just 300 lightyears (2,800 trillion km) away, it is somewhat “nearby”!

Is there intelligent life on this planet? We don’t know…and, even if there was, I don’t think they know about us either! I say this because we only started broadcasting our presence to the outer space about 125 years ago – albeit, inadvertently.

Our first radio communications signal was sent by Marconi in 1895. He didn’t aim it to outer space but most of it “spilled over” there. That signal has only travelled 125 lightyears to date (1.2 trillion km). It has not even reached halfway to Kepler 1649c!

The other question is, can we go and colonise such a planet? Our current technology cannot take us very far. That farthest traveled man-made object (Voyager 1) has reached only 22 billion km (22 light-hours) since it was launched in 1977 – over 42 years ago!

When will it reach Kepler 1649c? Definitely not in our lifetime…and, in any case, it is headed in the wrong direction!