Title: How many potentially habitable planets are there? (2019)
Headings: How many habitable planets are there?
How many habitable planets are there?
Table of Contents
What makes a planet habitable?
How many habitable planets are there in our solar system?
How are planets discovered?
1. Looking for stars that wobble
2. Observing shadows
3. Taking photos
4. Detecting starlight that has been bent by gravity
How many planets have been discovered beyond our solar system?
What makes a planet habitable?
So…how many “habitable” planets are there?
Conclusion: habitable planets in numbers

Content: There is only one habitable planet in our solar system: Earth. Although some planets, or planetary moons (like Jupiter’s Europa), could support some form of life such as bacteria or single-cell organisms, no other planet or celestial body in the solar system is capable of supporting humans. This means we need to look outside of our solar system, towards planets that revolve around a star other than our Sun. How are planets discovered? For generations, astronomers, philosophers, and other deep thinkers have theorized about the existence of planets located outside our solar system. As early as the 16th century, there was written speculation on this topic, and Isaac Newton, perhaps the most important contributor to physics in history, theorized accurately that our Sun is a star, and that the stars you can see in the sky would therefore also have orbiting planets. The problem for finding planets is that these bodies don’t reflect enough light to be detectable through typical observation methods – such as looking through telescopes, so more creative techniques are required. As often happens, advancements in science had to wait for advancements in technology; now that we have that technology, we can find numerous planets.