Hey, so I have a planet that has two suns. I was trying to have it so one sun would be up while the other sun was on the other side of the world, and then it would switch making it so everywhere was daylight all the time. Is this possible?
With science-as-we-know-it and only two suns, it is not. To set up the system as you’ve described it, it would have to look something like this.
(A, B, and C are positions in time, so that at time A, Planet and Star2 are at their respective As, and the same for B and C.)
This setup wont work to keep Planet in total daylight on all sides because Planet and Star2 orbit around Star1 at different speeds. The closer you orbit a body, the faster you need to go to stay in orbit.So, while both Planet and Star1 are at position A, the Planet has no nighttime. But, when Planet moves to position B, Star2 hasn’t moved quite as far and there is a part of Planet that is turned away from both stars. When they’re at position C, Planet sees both stars during the day, and has a regular night side that is turned away from both stars.
But, fear not, there are some ways to have a planet with no night. What it results in is some very spectacular, and very strange systems.
Solution 1: Multiple Stars. I mean A Lot of Them.
Situation: Your planet is in a star system with multiple stars - a lot of stars - six, eight, maybe even a dozen or more. So many that anywhere you are on your planet you can see one or more stars. You would have periods of bright day, very bright day, and not-so bright day. Rarely would you have no stars in the sky, and this would bring the occasional truly dark night.
Azimov postulates a planet like this in his novel Nightfall. Lagash is a thriving planet in a system with six suns, and gets nighttime only once every 2000 years. The people know nothing of the rest of the universe and think their planet and suns are all that exists. A couple of scientists predict when the next nightfall happens. and realizes that people will be traumatized by the darkness. When night arrives and the citizens of Lagash see the universe of stars in the night sky, they panic and destroy their own civilization - something they do every time it gets dark.
Hard-Science: Smaran Deshmukh and Jayant Murthy of the University of Bonn, have done the math and concluded that a system like Lagash’s is plausible, but might only be stable over a few hundred years. They continue to state that other solutions may be possible that are much more stable over a much longer periods.
Summary: Plausible, but not likely. Of course. in science-fiction, that’s good enough.
Solution 2: Artificial Stars Around the Planet
Situation: Your planet orbits one star, but your planet has several satellites that radiate heat and light in orbit around it. These mini-suns keep your planet bathed in total daylight. Actually, with a belt of artificial sun-satellites, a planet wouldn’t even need a real sun, and could just be travelling between stars.
Hard-Science: Those mini-suns could be small fusion or anti-matter reactors, or be powered by some sort of magical energy, according to what flavor you want your world to have.
Summary: Plausible. Mini-suns powered by SCIENCE or SORCERY are quite believable. They’d have to use a lot of fuel or pull energy from another dimension or whatever, but that’s just details.
Solution 3: We’re Really at the Center of the Universe And OhMyGodWereAllGoingToDie!
Situation: Your planet is ‘orbited’ by it’s stars.
Hard-Science: I lied. It’s actually possible to have a planet without night with only two stars, but I wouldn’t want to live on that planet.
The binary stars orbit around their mutual center or gravity called the barycenter. In the diagram below, that’s marked with a small red cross. If your planet was located right at that balance point, it would look like the stars were orbiting around the planet, and your planet would have no night.
The barycenter is also a Lagrange point between the two stars - an L1 point, and we know they’re unstable.
Summary: While technically possible, this situation is very very very unstable and is very very unlikely to occur naturally - and if it did. it wouldn’t last long. Very soon (like within a couple of hundred years or less), the planet would either drift into one of the stars or be ejected from the system entirely. Neither one would be very good for the planet.
Did I mention that this situation is very unstable?
However, if you have some sort of super-technology or wizardry, which would prevent the planet from drifting off, it could work. But with that power, why have real stars? Put up some artificial ones, move the planet, and you don’t have to live in a cosmic death trap. :-)
Solution 4: My God - It’s Full of Stars!
Situation: Your planet and it’s star is inside a globular cluster - a region of space that is just lousy with stars. Someone on your planet could see 100 times more stars than we can see with the naked eye from Earth. The night sky would shine with a total brightness of a couple-dozen full moons. Nighttime would be a slightly dim twilight instead of dark night.
Hard-Science: The stars around Earth are scatter about with an average density of 0.14 stars per cubic parsec (a parsec is 3.26 light-years). The stars within a dense globular cluster - like the one at 47 Tucanae - packs in several hundred stars in one cubic parsec.
Add more stars to the cluster to make the night sky brighter - but be careful! Adding in too many stars and you could cook your planet with too much radiation.
Each star would still be quite a distance away. Far enough that they would appear as points of light to the naked eye. But, there would be so many of them and they would be so very bright. From Earth, we can see 29 1st magnitude (very bright, like Sirius or Canopus) stars. From inside a globular cluster, you could see 10,000 or them,
Summary: Quite plausible, and very beautiful.
