While most people are familiar with the planets residing in our solar system from lessons taught back in grade school, it’s important to remember that our solar system is just a tiny blip in this ever-expanding universe. There are literally countless worlds existing in stellar systems besides our own known as exoplanets, and the number of known exoplanets is growing with each passing day thanks to space telescope observations.
For the most part, exoplanets are comprised of the very same elements that make up the planets in our solar system, albeit with different composition balances that give each exoplanet its own distinctive qualities. There are four primary exoplanet classifications, including Neptune-like worlds, Hot Jupiter-like words, Super Earth-like worlds, and Earth Analog-like worlds.
Neptune-like exoplanets are large and gaseous much like Neptune, and while they may not be the same color or size, they generally lack any terrestrial qualities. Hot Jupiter-like exoplanets are star-hugging gaseous exoplanets with extreme temperatures that occur due to their distance from their host star. Super Earth-like exoplanets are terrestrial worlds that make the Earth look small in comparison. And lastly, Earth Analog-like worlds are terrestrial planets that compare in size and composition to Earth.
When it comes to finding exoplanets, astronomers don’t generally get to observe them directly. Most of the time, they utilize transit events to detect their existence around other stars and measure the amount of blocked sunlight and frequency of blockages to discern how large those worlds are and how close they orbit their host star. In some cases, astronomers can even determine a world’s composition.
While thousands of exoplanets have been confirmed to exist thus far, most of those have been found right here in our own Milky Way galaxy and there’s no telling how many might be residing in the depths of the universe. With all the stars we can see in the night sky, one can only imagine just how many undiscovered exoplanets might be out there, and whether any might harbor intelligent life as the Earth does.