WATCH — Are aliens real? We asked an astrophysicist

Astrophysicist explains some theories for why we’ve never made contact with aliens

According to NASA, the chance that we’re alone in the universe is less than one in ten billion trillion.

OK ⁠— we know math can be hard.

That basically means that it’s more likely that aliens exist than not.

So where are they?

That’s the question that astronomers have been asking for years, most famously Enrico Fermi.

He noticed that there were billions of planets in our galaxy capable of supporting life and that intelligent life should be able to colonize the galaxy pretty quickly.

Yet we’ve never seen aliens.

Scientists estimate that there are roughly 60 billion planets in our galaxy that could support life. (AFP/Getty Images)

This contradiction is called the Fermi paradox.

For years, scientists have tried to come up with some explanations for this conundrum.

CBC Kids News contributor Mateus Soto spoke with astrophysicist Ilana MacDonald about some of these explanations.

E.T., pick up the phone!

Even if there’s a ton of microbial life out there, it’s possible that none of it has evolved to the point where it can communicate.

MacDonald says that “maybe there is no other intelligent life in the universe.”

Or it could just be a communication issue.

According to MacDonald, it’s possible that aliens know we exist and are just screening our calls. (Philip Street/CBC)

“Maybe they’re not interested in talking to us … they don’t feel like they want to be found,” said MacDonald.

The sting of rejection hurts, right?

Timing is everything

A more comforting option is that our calls just haven’t been received … yet, said Macdonald.

“We [could be] right at the beginning of intelligent life arising in the universe and other civilizations are at the same point we are … their radio signals just haven’t had time to reach [us].”

It’s also possible that civilizations just don’t last long enough to make it to other planets.

MacDonald suggests that things like war, natural disasters or even artificial intelligence could prevent civilizations from lasting very long.’ (Philip Street/CBC).

“Maybe a civilization only lasts thousands of years. Their radio signals went by us, our civilization arose and we never had a chance to hear from them.”

It’s also possible that we just don’t speak alien.

“They could have found a whole new way of communicating that we haven’t thought of, and if we could tune into it, we’d be part of a conversation that we’ve been missing out on for thousands of years,” said MacDonald.

For more interesting space facts, check out parts 1 and 2 of our series on space.