Are we alone in space, or is it more likely the universe is teeming with life?

It’s very hard to get your head around how vast the universe is and how many stars and potential planets there are. So let’s understand - How big is the universe?

Astronomers have estimated that there are 10^22 to 10^24 stars in the Universe (EuropeanSpaceAgency)

That is 100,000,000,000,000,000,000,000 stars.

Picture from my home in Palmerston North, New Zealand

It’s also estimated that there would be at least 1 planet for every star. Our Sun of course has 8 planets and lots of moons and moons can of cause also support life in the right circumstances.

But a number like that is still it hard to imagine how big it really is.

There is a saying goes that goes “There are more stars in the universe than there are grains of sands on all the beaches on Earth”. Obviously, it’s a bit of an estimate but as it turns out “there are 5 to 10 times more stars than grains of sand on all the world beaches”. (https://www.universetoday.com/106725/are-there-more-grains-of-sand-than-stars/)

So, one of the best ways I find to image how big the universe is:

Go down to the beach and pick up a single grain of sand. Now imagine that small grain of sand between your fingers is our earth. Now look down the beach and imagine every other grain of sand on this beach and every other grain of sand on every other beach is a planet and you’re still be short of the number. That’s how many planets are out there – Earth is just 1 planet in a sea of planets.

So, could some of these other planets have life on them – what do the experts say:

A recent SETI press release Oct 29. 2020 has estimated the following:

“Thanks to new research using data from the Kepler space telescope, it’s estimated that there could be as many as 300 million potentially habitable planets in our galaxy. Some could even be pretty close, with several likely within 30 light-years of our Sun. The findings will be published in The Astronomical Journal, and research was a collaboration of scientists from NASA, the SETI Institute, and other organizations worldwide.”

And that’s just our galaxy and there are hunders of billions of galaxies.

Now back to the question: Is it likely we are alone in space?

With the share number of potential habitable planets in our galaxy, it would seem very unlikely that earth is the only planet with life on it.