Are We Alone in The Universe?

Today, we live in an age of exploration, where robots on Mars and planet-hunting telescopes are beginning to allow us to edge closer to an answer.

Is There Life on Other Planets?

The number of planets in the Milky Way galaxy is estimated to be around 100 billion. Of those, only about one percent are known to have the right ingredients for life. So it’s safe to say that there are vastly more planets out there that could support life, if we can only find them.

But even if we found a planet that was hospitable to human beings, who knows how many aliens might be living on it?

Recent estimates suggest that there could be between 100-500 billion alien beings in the Milky Way galaxy alone. This is a huge number, and it’s difficult to even imagine the potential implications of this knowledge. It suggests that aliens are probably more common than we thought, and that there could be literally billions of intelligent life forms out there waiting to be discovered. If this is true, it would completely change the way we view ourselves as a species, and force us to confront some pretty fundamental questions about our existence.

The Drake equation

While we wait to establish contact, one technique we can use back on Earth is an equation that American astronomer Frank Drake formulated in 1961. He came up with an equation to estimate the number of detectable extraterrestrial civilizations that may exist in the Milky Way galaxy. Each variable, visualizes in the infographic below, is a crucial factor for developing such a civilization.

The Fermi paradox

The Fermi paradox is a puzzling observation in the field of physics that poses a challenge to the prevailing theory of the universe. According to this theory, the universe is expanding and has been doing so for almost fourteen billion years. Yet despite its vast age, we have not found any evidence of advanced civilizations beyond our own. This paradoxical situation is sometimes referred to as the “Great Silence”. In order to explain this strange fact, some scientists suggest that there must be forms of life that do not produce detectable signs of their presence, or that these civilizations have simply not reached a point where they are capable of broadcasting their existence into space.Whatever the case may be, it remains an intriguing question that has yet to be fully resolved.


In the age of exploration, we are constantly discovering new things about our universe. We’ve discovered planets beyond our own and now we’re even exploring space with robots! We’ve discovered that the Earth isn’t the center of the universe and now we’re even finding evidence of life on other planets. The world has become a lot more exciting and interesting in the last few hundred years.

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Infographic: How Many Aliens Are There In Our Galaxy?

2 thoughts on “Are We Alone in The Universe?”

  1. I love the layout of this one – it makes the information easy to follow. I especially love the interactive version, so you can follow along in some sort of order.


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