Have you ever wondered if the sun is getting smaller each day? Let’s dive into the fascinating world of solar science to uncover the truth behind this popular question.
## The Sun’s Composition and Energy Source
🔍 To understand if the sun is shrinking, we first need to grasp its composition. The sun is a massive ball of hydrogen undergoing nuclear fusion, which produces the energy and heat we feel on Earth.
## The Sun’s Size Over Time
📏 While it may seem logical that the sun would shrink as it burns through its hydrogen fuel, researchers have actually found that the sun is gradually expanding. This phenomenon occurs as a star ages, becoming larger and brighter over time.
## Why Isn’t the Sun Shrinking?
❓ So, if the sun is continuously burning hydrogen fuel, why isn’t it getting smaller? The answer lies in the balance between gravity and nuclear fusion within the sun. As the sun fuses hydrogen into helium, it exerts outward pressure that counteracts the force of gravity, maintaining the sun’s size.
## Conclusion
🔬 In conclusion, while the sun is not getting smaller each day, it is gradually expanding as it progresses through its lifecycle. The intricate balance of forces within the sun allows it to sustain its size and energy output for billions of years to come.
Next time you gaze up at the sun, remember the complex interplay of forces keeping it shining brightly in our sky! 🌟
Stars stay broadly the same size because there’s a delicate balance of gravity pulling them inwards and the energy from fusion pushing them outwards. The Sun IS losing mass as it converts it to energy but not a significant amount compared to its mass. Once the hydrogen is depleted, gravity will, briefly, win, pulling the Sun’s core closer together while the outer layers get expelled into space. Then helium fusion will begin and the Sun will swell to a larger size.
The sun does get smaller every day, but it’s like the Earth losing a single sand grain each day: it’s not a factor. To be clear, the Sun doesn’t burn in the traditional sense, it’s not combusting. It works on nuclear fusion.
It loses mass due to solar wind: the radiation carries away a constant stream of plasma, and breaking magnetic field lines eject large amounts of mass.
Most of the fuel is still in the sun after fusing, it overwhelmingly doesn’t leave, so mostly no.
A TINY bit of mass leaves in the form of the solar wind, but it’s infinitesimally small versus the total mass of the sun, and less than the fuel fusing. It won’t add up to any important amount by the time the star reaches the end of its life and more relevant things happen.
Gravity, the material is converted from some molecules to anothers, from some atomic elements to others, usually Hidrogen to Helium, later Helium to heavier elements. I also heard a theory that the sun is not just a ball of gas but that it has a material core and a plasma alike atmosphere …
Ask this a slightly different way and a better answer can be given.
Is the sun losing mass continuously?
Yes, the sun loses mass via the solar wind (charged particles) and via mass ejections of coronal material. It also loses mass as photons carrying away energy from heat released by fusion reactions, but this loss is relatively small. At the same time, the sun is expanding as the core becomes denser and hotter which forces surface layers to expand. So the sun is getting larger but losing mass. It has enough mass to support itself for several billion more years after which it will expand enough to wipe out the inner planets.
If I remember correctly, the sun will turn into a red giant. Right now, most of the fusion happens in the core. As this fuel depletes, it exerts less pressure, so gravity then causes the core to become more dense. This, in turn, makes the core hotter, making the outer layer hotter with fusion happening there, too. This then causes the sun to swell. It will swell to 100-200 times its current diameter. So long-term, it gets bigger and less dense.
The scale of the sun is hard for the mortal mind to imagine. Basically, it’s a highly compressed ball of gas that’s so large the gas is compressed to the point of undergoing fusion due to its own gravity. Fusion is a high energy process that releases enough explosive power to keep the ball of gas from collapsing any further. It’s also a highly efficient process. Not to get too technical because most of it will be lost in translation, but given the size of the gas ball that has to exist in order for these processes to happen, means that the sun has enough fuel to last billions of years.
Several YouTube channels, such as Kurzgesagt and Veritasium, have had several stints of producing videos which explain in detail the complexities of the different scenarios of stellar formation, fuel consumption and eventual death – this is a great question, so if you’re interested in learning more, I’d highly suggest those or other sources of information!
It’s losing mass, but at the same time the Sun’s diameter is gradually increasing as the rate of fusion increases. This is happening because helium is accumulating in the core, causing the core to become smaller and denser, increasing the rate of fusion.
It’s actually getting bigger. While hydrogen is fusing into heavier and denser elements in the Sun, that is not really what is governing it’s size. Size of a star depends most on it’s temperature, exact composition is less important. Hotter star will have all it’s plasma expand to larger size. It’s temperature does depend on it’s mass and composition though, older stars with more heavy elements have denser cores, with more fusion going on, therefore they are hotter and swell to larger size. At end of it’s life Sun will increase in size to a red giant hundreds of times larger than it is today and yes, it will also destroy Earth.
It’s not burning at all.
It’s fusing Hydrogen atoms with other hydrogen atoms to form helium atoms.
Helium is more dense than hydrogen, so you might expect it to get smaller and shrink.
The fusion process releases a lot of energy though, which heats up the surroundings and causes them to expand. The more that fuse, the more it expands.
The shrinking and expansion combat each other and for a very long time the sun will remain a relatively stable size, but slowly growing.
It’s not burning like you’re probably thinking hydrogen burns that requires the presence of an oxidizer like oxygen which gives water as the product. It’s fusing hydrogen atoms into helium. There are ofc ejections of solar material with things like solar flares but it’s not being ‘consumed’. The hydrogen is but then when that runs out, the sun will get super extra huge and start fusing the helium atoms into heavier elements.
Yes, but not by as much as you might think.
The sun loses some mass to solar wind, which is blown off of the surface by radiation pressure and magnetic forces, but this is not directly a result of the “burning”. The “burning” itself is not really combustion, which is a chemical reaction, but fusion, which is a nuclear reaction. Atoms of hydrogen are squeezed so tightly together they become atoms of helium, and in this process, gamma rays and neutrinos are released, which, either quickly or slowly, are released from the sun, both of which also lower its mass. However, the majority of the mass of the protons that fuse remains in the sun as helium. There are also a number of other fusion reactions that occur in the sun that take various heavier elements and convert them into even heavier elements, also releasing energy and thus mass, but these are minor compared to the proton/proton reactions for a star of its size.
The net result is the sun loses about 5-6 million metric tons of mass every second. This seems like quite a lot, but the Earth weighs about 6 sextillion tons (21 zeroes), which means it would take about 1 quadrillion seconds, or over 30 million years, for the sun to lose one Earth mass. The sun itself is 330000 times bigger than Earth, so even 30 million years of constant shrinking is only enough to make it smaller by a miniscule fraction of a percent.
Stars aren’t really “burning” in the traditional sense like how you imagine a fire burning, they are undergoing nuclear fusion which happens to release quite a bit of energy in the form of electromagnetic radiation. Nuclear fusion happens when there is sufficient force (gravity) to crush atoms together so hard that it overcomes the strong nuclear force and their nuclei fuse together (hence fusion).
It does lose mass over time from this process, but it’s a relatively small amount compared to the overall mass of the Sun. So it is technically getting smaller, but it will take billions of years before that mass loss becomes problematic for the solar system.
The Sun doesn’t “burn” it’s fuel the way a piece a normal fire would. The Sun fuses 2 hydrogen atoms into 1 helium atom. A helium atom weighs just a tiny bit less than 2 hydrogen atoms because that difference in mass was turned into energy, but even then you still have +99% of the original mass still there. So yes, the sun does get a tiny bit lighter with every fusion reaction that happens but it’s such a miniscule amount compared to the total mass of the sun that it is basically negligible.
Astronomer here! This is tricky because the *mass* of the sun is not actually getting smaller over time a measurable amount, and it’s actually getting *bigger*!
To address the first point, as you said the sun is burning, and Einstein told us, E = mc^2 . What this means for the sun is as the mass in it is converted into energy, aka burning hydrogen, it becomes less massive over time- 1.353×10^17 kg a year, which might sound impressive, but one comet is easily 10^13 – 10^14 kg in mass. Several of those hit the sun every year, plus of course the sun gains mass via all the random dust that hits it as well… so overall, the change in mass probably is negligible. I guess it’s probably net decreasing a *tiny* amount over time, but pretty insignificant compared to all the mass of the sun.
A second effect of all this is the sun over time is converting hydrogen into helium at its core, causing the core to contract in size (less mass THERE, not overall, as we just discussed), and this means the outer layers of the sun expand in size as there’s less gravitational mass holding them tight. As such, the sun is actually something like 15-20% *bigger* than when it was born ~4.5 billion years ago! This process will keep going by the way- as you may have heard, the sun will someday be a red giant that will swell outwards so big in size that the Earth might be swallowed (Mercury and Venus definitely will be). Incredibly, the question isn’t whether the sun will reach our orbit in size- it definitely will- but just that over time, as it runs out of fuel and its mass decreases slightly, the orbits of the planets will go outwards so the Earth’s orbit just *might* be bigger at those later times to save us from being swallowed by the sun. But, as you learned in point 1, knowing *exactly* how much mass the sun will lose over billions of years in the future is a tricky calculation.
I hope this answers your question, but let me know if something is unclear!
The sun isn’t “burning” in the traditional sense, but it is in fact getting smaller. Nuclear fusion in the sun converts roughly 600 billion kg (6e11 kg) of hydrogen into helium per second. From that 600 billion kg of matter consumed in fusion, roughly 4 billion kg (4e9 kg) end up converted into energy. While that seems like a lot (and it is) it’s still miniscule compared to the sun’s mass, which is around 2e30 kg, i.e. 2 trillion billion billion kg. 2e30 / 4e9 = 5e20 seconds = almost 16 trillion years for the sun to dissipate if it kept up that rate of loss indefinitely (which it won’t but that’s a different question)
To try and visualize that, consider that a liter of water weighs 1kg, and 1m3/1000 liters of water weighs 1000kg. 4 billion liters/kg of water would be a pool 4m deep and a kilometer on each side, or 0.004 km3. That seems like a lot but again it just underscores how enormous the sun is, because its volume is over a billion billion km3. Removing 0.004 km3 from the sun is about the same as removing 2 liters of water from the Pacific Ocean
Burning isn’t really the right word, as it isn’t combusting and isn’t a chemical reaction. When wood or paper “burns away”, the solid item “burns away” because a lot of the reaction outputs are a gas.
The mass of the sun is around 2×10^30 kg. It loses mass through fusion (some mass is converted to energy) and through solar wind and coronal ejections.
However, despite that, the amount of mass lost is still very small compared to how massive 2×10^30 kg actually is. Remember, even if the sun lost half its mass, it would still be 1×10^30 kg!
One estimate I found is that it loses an Earth of mass over 100 million years, but it has the mass of 330000 Earths. So, you aren’t going to see a size change if it takes millions of years to lose a fractional percent of mass.
It’s getting less massive everyday as mass is converted to energy, as for size and density that varies over time and increasing or decreasing depending on the repulsive force of hot gas plasma pushing outward and gravity pulling inward. Density could be tiny and size immense while in a red giant phase or density enormous and size small while a white dwarf or even a neutron star all the way to black holes. So can go from average size to large and down to very small at end of life.
Note: as the Hydrogen fuses to Helium it only loses .7% mass and the Sun has been burning for over 4 billion years, as a percentage it is not losing much mass on a daily basis (only a small amount of material is actively fusing at any one time) nor will it lose much mass in the entirety of its life (excluding nova and supernova events).
The sun is too massive and nuclear fusion is too efficient. The sun loses about 4 million tons of mass every second by converting mass into energy. But it is so massive that it would take the sun about a trillion years to lose all its mass at this rate
Actually getting bigger. Why? Dunno the cheMistry behind… Reduced gravity?
Lower density gases left behind..?
Either way, eventually it will turn into a white giant and swallow every planet in the solar system, probably Pluto too for good measure..
And even later a red dwarf, basically a “tiny” (for a star anyway) smoldering coal of its former self.
[Here’s an excellent BBC article asking the same question](https://www.sciencefocus.com/space/if-the-sun-is-constantly-losing-mass-via-nuclear-fusion-how-come-its-not-getting-any-smaller)!
Essentially, the sun isn’t burning fuel in a traditional sense, it fuses lighter elements like Hydrogen into heavier elements (in this case, Helium). The act of fusing those lighter elements causes [a small amount of mass to be lost](https://en.wikipedia.org/wiki/Nuclear_fusion#:~:text=The%20fusion%20of%20lighter%20elements,energy%2C%20such%20as%20electromagnetic%20radiation.).
The sun loses additional mass due to solar winds and other ejections. Overall, [the sun loses approximately 350 million tons of mass each day](https://www.sciencefocus.com/space/if-the-sun-is-constantly-losing-mass-via-nuclear-fusion-how-come-its-not-getting-any-smaller). While it sounds like a ton (ha), this represents a miniscule fraction of it’s overall mass, [0.0000003067%](https://www.vaia.com/en-us/textbooks/physics/physics-2-edition/chapter-26/problem-40-the-solar-energy-arriving-at-the-outer-edge-of-ea/#:~:text=Short%20Answer&text=Answer%3A%20The%20Sun%20loses%20approximately,6%20%25%20of%20its%20total%20mass.), daily.
Now for the last part of your question – if it is losing mass, why isn’t it getting smaller? Stars are rather interesting things – there is a balance between gravity (inward pressure) and fusion (outward pressure) that exists for the life of the star. As mass is lost, the outward pressure starts to win out over the inward pressure, and the size is (relatively) maintained. This won’t always be true, and as our star stars to shed further mass and begins to fuse heavier elements (like Helium), it’ll eventually grow to become a [red giant](https://en.wikipedia.org/wiki/Red_giant), encompassing Mercury, Venus, Earth, and potentially Mars.
Thankfully, that won’t happen anytime soon.
It’s not really “burning”; that typically implies that it’s reacting with oxygen in the process of combustion. The hydrogen of the sun is undergoing fusion, which is something quite different.
As for getting smaller and smaller, it’s not doing that at all; it’s actually getting larger and larger. This is not so much directly related to the process of fusion itself, but more to the end result of that process where the core becomes denser and hotter and causes the outer layers to expand outward.
Also, keep in mind that when something burns here on Earth, it’s technically actually gaining the mass of the oxygen it’s reacting with rather than losing mass. The reason it seems to become smaller is because the products of combustion typically are hot and gaseous and fly off into the atmosphere; if you were to do a controlled combustion inside a sealed chamber, you’d see that the total mass in the chamber (oxygen and combustible material) wouldn’t change noticeably at all.