Eli5 How do scientists calculate the “habitable zone” of a solar system, both in ours and other systems?


What kind of factors go into a calculation like this?

In: 2

The main thing that matters is temperature, habitable zone means water must be able to be in the liquid state.

Temperature depends on the stars radiation and distance. From brightness and size of a star you can calculate how much light it radiates wich then gives a curve of possible temperatures around the star (if you move further away the density of light that hits a potential planet goes down with distance squared)

Especially for very small stars other nasty effects can make the habitable zone smaller, for example very close to the star there can’t be stable planets due to the immense tidal forces of the stars gravity. Our closest star Proxima Centauri for example has no habitable zone as the range of good temperatures is so close to the star that no planet can exist there.

Only one factor.

The stars luminosity. Our suns luminosity is 1.

Than you compare the star to our sun. If the star is brighter or dimmer its habitable zone has to be further/closer.

The “habitable zone” just defines a rough area around a star where liquid water **may** exist depending on the stars brightness. It does not define if the planet has an atmosphere, a strong enough magnetic field and so on. But it helps to spot planets that we may want to take a closer look on in the future.

The habitable zone, also known as the “Goldilocks zone,” is the region around a star where temperatures are just right for liquid water to exist on the surface of a planet. This is considered an important factor in the potential for life to exist on a planet.

Scientists calculate the habitable zone of a solar system by considering the distance of a planet from its star and the amount of energy that the star emits. They use models that take into account factors such as the planet’s orbit, its atmosphere, and its ability to retain heat from its star in order to estimate the temperature on the planet’s surface.

In our solar system, the habitable zone is considered to be in the region between Venus and Mars. Venus is too close to the Sun, and its surface is too hot for liquid water to exist, while Mars is too far away, and its surface is too cold. Earth is located in the habitable zone and has temperatures that allow for liquid water to exist.

To calculate the habitable zone in other solar systems, scientists use telescopes to observe the stars and planets in those systems. They use the data they gather to estimate the distance of the planets from their stars and the amount of energy that the stars emit. They then use this information to estimate the temperature on the planets’ surfaces and determine if they are in the habitable zone.

It’s worth mentioning that the concept of habitable zone is just an estimation, and it’s not definitive. Even if a planet is located within a habitable zone, it doesn’t mean that it’s inhabited. There might be other factors like the atmosphere, geology and the magnetic field that can affect the habitability of a planet.

sun hot and get cooler at a distance booga

planet got atmosphere keep heat in booga booga

for example venus has dense atmosphere to much heat cant let heat out

mars to little atmosphere cant keep heat in(mars got no Magnetosphere)


its a mix of both the density of atmosphere of planet and the distance from the sun. scientist calculate both so in essence habitable zone doesn’t exists.


lololololololololololololololol fun breaking your brain matter as a 5 year old lolololol


so in essence I have no clue lol

It’s an estimate of where water could exist in a liquid state on a planet’s surface.

That’s all it’s about. It’s not actually considering any factors for habitability other than “could water exist there”. It’s not even “does water exist there”, just whether it could.

How you calculate that can vary a lot, because things like the planet’s atmosphere and size and composition can change its surface temperature a lot. This is why estimates vary quite a bit, there are many different ways you could account for these other factors.