There are over 300 million worlds home to similar conditions to Earth in the Milky Way Galaxy alone. Astronomers estimate there are approximately 2 trillion galaxies in the observable universe. That is 2 Trillion with a T.
Why is it absurd to think there is only life on Earth? Well, because of the math involved in exploring the cosmos. But let me elaborate and let us speak numbers.
Are we alone in the universe? Is there life elsewhere? These are perhaps some of the two most sought-after answers in the history of humankind. And if we look at how much we have learned about the cosmos in the last few decades, then we probably should know the answer. We have obtained a great deal of knowledge about our cosmic neighborhood. We continue exploring our solar system while maintaining our eyes on some of the deepest parts of outer space. With new technology like the James Webb Space Telescope, our understanding of the cosmos is refined like never before.
Nonetheless, we still have no conclusive evidence that there is life elsewhere. We can, nonetheless, make an educated guess. In fact, some scientists are convinced that there could be life elsewhere in the solar system. These places include some far-away mons like Enceladus or Europa. Life could exist on Mars, deep beneath the surface. But this is not the reason why I am convinced there is life elsewhere.
Why it is absurd to think there is only life on Earth
We have known for a few years now that over 300 million worlds are home to similar conditions to Earth in the Milky Way Galaxy alone. Imagine that. 300 million planets that have similar conditions to that of our own planet. Although we have not directly seen these worlds, we know they exist, and we know this thanks to science. According to NASA, there are 5,235 confirmed exoplanets as of writing. There are nearly 10,000 worlds awaiting confirmation. And we have discovered a total of 3,913 planetary systems. These numbers are only set to increase in the future as we polish our technology. Out of these 5,235 confirmed worlds, the no-retired Kepler space telescope spotted more than 2,800.
300 million Earth-like worlds?
300 million, indeed. And to come up with this number, scientists used the help of the European Space Agency’s Gaia Spacecraft. This spacecraft is used to monitor stars in our galaxy. With the help of Gaia, scientists could finally determine how many planets similar to Earth, orbiting stars similar to the sun, exist. And what is even more exciting is that the nearest Earth-like world lies within 20 light-years from us.
2 Trillion galaxies
But our universe isn’t just the Milky Way. And here is where it gets even more interesting. By observing galaxies in deep space and exploring the cosmos throughout the years, astronomers have estimated there to be as many as 2 trillion galaxies in the observable universe. That is 2 Trillion with a T. How do we know this? This is based on the deepest image taken by Hubble, the so-called Hubble eXtreme Deep field. It revealed some 5,500 galaxies in an area that makes up just 1/32,000,000th of the sky. By doing the math, scientists can estimate the number of galaxies out there. And based on our current understanding, some 2 trillion alien galaxies are waiting to be explored. These galaxies have innumerable stars orbited by innumerable worlds. Why is it absurd to think there is only life on Earth? Because of the math behind the vastness of the universe. This is even more than the number of galaxies Carl Sagan ever imagined to be.