As the human race is looking for possible ways to travel to and live on Mars, we have our eyes to the heavens looking for more habitable worlds in our galaxy. Many people do not realize that astronomers have identified more than 500 planets orbiting other stars. Planets we find around other stars we call exoplanets, short for extrasolar planets.
Having the technology to find exoplanets is only a very recent occurrence. The first confirmed exoplanet was found in 1992 orbiting around an object called a pulsar. Since then, technology and telescopes have improved at a dramatic rate. New techniques have also been developed to detect these planets orbiting other stars. In case you are not aware, finding exoplanets is extremely difficult because the host stars are so incredibly bright that you cannot normally see the planet orbiting the star. But, armed with these new techniques, we can look at the number of exoplanets found each year. This data is publically accessible here.
As you can see, each year, more and more exoplanets are discovered. In fact, an exponential curve fits the data quite nicely. However, in 2009 a new mission was launched by NASA called Kepler. It is a telescope that orbits the Earth and looks for exoplanets. It is too early to confirm any of the data it has taken so far, but so far they have 1,235 unconfirmed planets that are circling 997 different stars. That is an extraordinary amount of possible planets and would greatly accelerate the pace of the above curve. From the preliminary Kepler data, it is possible to estimate that there are over 50 billion planets in our galaxy.
So, next time you look up, just think that there are billions of other planets in the galaxy looking right back at you and who knows what we will find there, but isn’t it exciting just to know that they are there?