There May be as Many as 100 Billion Habitable Planets in the Milky Way Alone
A new study suggests that previous estimates have been far too low, and there may be as many as 100 billion habitable planets in our galaxy alone.
The search for habitable planets in our galaxy has become more than just a fascinating hobby, it’s turned into something of an obsession. Hundreds of potentially habitable planets have been found within a range of roughly 50 light years, exciting our imagination and giving us hope for life beyond Earth, maybe even a possible second home. And as it turns out, finding these planets may be a little easier than scientists first thought.
Based on new calculations there may be more planets in the Milky Way than initially thought, many, many more. According to the new study, there may be as many as 100 billion habitable planets in our galaxy, and that is a conservative estimate if the math is correct.
The study comes from a series of calculations based on the mass of our galaxy. The current method for finding planets involves observation of the galaxy including studying gravitational patterns to find celestial objects, but given that we can’t step out of our galaxy and look back in our range and the number of stars we can observe is relatively low – still in the billions, but that’s a tiny number compared to the total number of stars in the universe.
The new calculations estimate the total mass of the galaxy and differentiate that mass to differentiate the number of stars in our galaxy. The results suggest that the Milky Way may contain a minimum of 400 billion stars, and the actual number may be much higher.
In 2013, the best estimate was that there were at least 17 billion planets located within in the Goldilocks zone of stars, meaning they orbit a star at a distance that would potentially offer the right amount of light and warmth for liquid – not too hot that it would boil away or too cold that it would freeze. That earlier calculation equated to roughly one out of every four stars in the Milky Way hosting a planet capable of supporting life. That number holds true, so with 400 billion stars that makes for 100 billion potentially habitable planets.
Of course, there’s a big leap between habitable and potentially habitable, and given our current level of technology, there is no easy way to confirm if any of these planets actually could sustain life – or more accurately, contains water. For that, we’ll have to either develop technology that can get a closer look at distant spatial objects or send some craft out to the individual planets. At the moment, neither is possible. But one day.
Given that this is all based on speculative math and can’t be proven, there is, of course, disagreement about it. Some believe the 100 billion figure is wildly inflated, and the actual number is closer to the original estimate of 17 billion. That’s a significant difference, but it still means that the odds of finding another Earth-like planet are very high, even if it happens years, or decades from now if not longer.