There are sunsets on other planets even more magnificent than the ones on Earth. What if we could see not just one, but two suns falling below the Earth’s horizon? Would our planet get much warmer with two stars heating up? Would we ever reencounter nighttime? Could our binary star system be able to support life?
Here’s what would happen if we had two suns. Not all-star systems form around a single star. Binary or multiple star systems appear to be more common than the ones with a single star.
What is a binary star system?
A binary star is a star system consisting of two stars orbiting around their common centre. These systems of two or more stars are called multiple star systems.
Is there any other Star Companion of Sun ?
Some scientists even suggest that our Sun once had a star companion – a long-lost dwarf star called Nemesis. It broke free of the Sun’s gravity and merged into the Milky Way billions of years ago.
Our search for Earth-size planets throughout the galaxy showed us that, not only most star systems binary, but they also have habitable zones and planets within them.
Can life sustain under two Suns and how?
It looks like the Earth could sustain life with two suns, instead of just one. But only under certain conditions.
In a binary star system, the masses of the stars to their position relative to Earth and each other.
If one of the suns was bigger and brighter and had a much stronger gravitational impact on us, that Sun could pull the planet towards itself. We’d get pretty crispy before disappearing in its solar flares.
On the other hand, if neither stars’ gravitational pull were strong enough, the Earth would fly out into space. We would become one of those rogue planets that travel the Universe all alone with no star system to call home.
Will Earth’s rotation be effected?
Let’s assume that the Earth’s orbit would be stable with two suns.
Case 1: That would be possible if the Earth orbited just one of the suns. But with two suns, each on the other side of the Earth will complicate life on the planet. Because at some point the stars would face both sides of the Earth at the same time.
Not only that would that take away our nights, but it would also increase the Ultraviolet radiation and solar winds. Two suns will burn all human lives.
Case 2: The Earth’s orbit could be stable if the planet rotated around the two stars in the centre. The stars would have to be close together, and the Earth’s orbit would be further away.
But the distance from both the star will be beyond the habitable zone, where the heat of the suns wouldn’t be enough to keep our water in a liquid state. The planet would turn into a frozen, lifeless rock.
The best-case scenario for our planet would be if we replaced our Sun with two similarly matched stars, each half as bright as the Sun. That would keep the Earth warm enough to sustain life.
Because the total gravity of the two stars would be stronger, it would take the Earth 280 days instead of 365 to make a whole circle around them. A year on Earth would be shorter, but not dramatically.
The distance between the stars would have to be less than 15 million kilometres apart (9 million miles). The less the distance between stars, the safe we are on Earth. That way, the orbits of all the planets in our system would be stable, even Mercury’s.
How will the Eclipse effected?
The two stars would orbit each other once every 10 days. Every 5 days, one star would cross in front of another. From Earth, that would look like a solar eclipse, but instead of our Moon blocking the Sun, it would be one star blocking another one. And instead of 7.5 minutes, that Eclipse would last for about 6 hours.
Under these conditions, the Earth could be just fine orbiting two suns. The only question is whether the Earth would have formed in a binary star system in the first place.
As far as we know, the smallest known planet circling two suns is a gas giant much bigger than Earth. Maybe there is a small, rocky planet like Earth orbiting two suns somewhere in the Universe. We just haven’t found it yet. It might even sustain life, intelligent enough to send a signal to our planet.