Everyone loves sunset and sunrise. They look so spectacular that people would stop their cars and look at them. Other planets would have even more eye-catching sunsets than Earth. How would you like to see not just one, but two Suns falling below the Earth’s horizon? Would the temperature of our planet increase significantly if there are two suns? What if we never experience the night time again? Is it possible to sustain life on a binary star system?
Let’s see what will happen if we had two suns in our solar system. Like our solar system, not all solar systems are formed around one star. There are many star systems with binary or multiple stars, it’s very common.
There is also a possibility that our Sun once had a star companion that broke free from gravity and moved away into our galaxy billions of years ago.
We have been searching for an Earth-like planet from a long time. This has shown us that many star systems are binary and have habitable zones and planets within them.
Under certain conditions, it is quite plausible that the Earth would sustain life even with two suns.
In such a binary system, the possibility of life on Earth would depend on many factors like masses of the star, their position relative to Earth and each other.
It is highly probable that the Earth’s orbit would be very unstable in this case. If one of the suns was bigger and brighter as compared to others, then it would have a strong gravitational impact on Earth and hence would pull us towards it. We would definitely burn in this case.
But if both the sun’s gravitational pull is not strong enough, Earth would not remain in orbit and would surely fly away into space. It would become a rogue planet with no star or would find another star lightyears away.
Let’s assume that the Earth’s orbit is stable. This is possible if Earth orbited only one sun. But this would not be the ideal condition for the life on the planet as at some point, Earth is bound to face two suns at the same time on the opposite end.
If this happens, there would be no nights on Earth. And it would also mean double UV radiation and solar winds. We would surely get toasted in this case.
Earth’s orbit can become stable if the planets rotated around two suns. In this case, two suns/stars would have to be close to each other and the planet’s orbit further away from both.
But how far away should the Earth be?
It should be beyond the habitable zone, where the heat of suns wouldn’t be enough to keep water in a liquid state. Earth would turn into a frozen, lifeless rock.
You might ask, then what is the use of reading this? Well, I said it is possible under certain conditions.
It would be possible if we replaced our sun with two similar stars that are half as bright as our Sun. This would ensure that only enough warmth is provided just to sustain life. Here the overall gravity would be stronger and would take around 280 days to make a whole circle around with suns.
Here, the distance between the stars would have to be less than 15 million kilometers apart. This will ensure that the orbits of all the planets in our solar system are stable.
Let’s assume that the distance between the suns was about 5 million kilometers. In this case, two suns would orbit each other every ten days. We would be able to see a solar eclipse, but instead of the moon there would be another sun blocking the other sun. This solar eclipse would last for more than 6 hours. Under such conditions, the earth could be stable and sustain life orbiting two suns.
But we don’t know for sure if the Earth would have actually sustained life if our solar system was a binary star system to start with. Let’s hope that there is a planet somewhere in the Universe that is orbiting two suns and have life.