How Many Exoplanets Have Been Discovered, and How Many Are Waiting to Be Found?
An artist’s illustration of Kepler-11, a small, cool star round which six planets orbit. (Credit: NASA/Tim Pyle)
Astronomers estimate that there’s roughly one exoplanet per star in our galaxy. Of course, some stars have many planets – our personal solar has 9. And some stars have none. But if a star lives lengthy sufficient, forming planets appears to be the rule, fairly than the exception.
That doesn’t imply astronomers can map all of these billions of stars although. When it comes to exoplanets which were measured or counted indirectly, the numbers are a lot smaller.
The working counter of identified exoplanets – as of this writing – stands at four,108 confirmed targets. But astronomers are surprisingly good at determining what they can’t see. They know that their telescopes aren’t highly effective or exact sufficient to see the stealthiest planets – these which might be very small, very removed from their stars, or round stars very removed from Earth. And conversely, there are areas of house the place astronomers are fairly assured they’ve discovered all of the planets inside a sure vary.
By combining the data of what they will see – the identified exoplanets – with the data of what they will’t see – the elements of house at present past our potential to examine – astronomers find yourself on the approximation of 1 planet per star.