If we could travel beyond our solar system, what could we see beyond it?

 Punch through our solar system's protective bubble, and your first encounter wouldn't be another star. The void is a wasteland of billions of unseen, freezing planets wandering the dark alone.

The space between stars is filled with the interstellar medium—a diffuse, cold mixture of hydrogen, helium, and cosmic dust. Drifting in this darkness are these rogue planets. Violently ejected from their home solar systems during chaotic early formations, they are unbound to any star and remain frozen in perpetual night. They are practically invisible, detectable only when their gravity briefly magnifies the light of a background star.

The closest stellar stop would be the Alpha Centauri system, located 4.37 light-years away. Rather than a single sun, a traveler would find a triple star system. The two main stars, Alpha Centauri A and B, orbit each other closely, bathing their surrounding space in the glare of two suns. The third, Proxima Centauri, is a small red dwarf swinging in a wide orbit. Orbiting Proxima is at least one Earth-sized exoplanet, Proxima b. On its surface, the red dwarf would loom large in the sky, casting a permanent, crimson twilight over the landscape.

Further into the galaxy, the dark void gives way to stellar nurseries. These are massive clouds of gas and dust spanning light-years across. Under their own gravity, pockets of gas collapse and ignite into newborn stars. The intense ultraviolet radiation from these young stars sculpts the surrounding dust into towering, jagged formations, such as the famous Pillars of Creation.

The Pillars of Creation as captured in near-infrared light by the James Webb Space Telescope, revealing clouds of interstellar gas and dust where new stars are forming. Source: Wikimedia Commons.

Deeper exploration would reveal the violent ends of stellar lifecycles. A traveler might encounter a pulsar—the crushed, spinning core of a dead star, firing twin beams of radiation across space like a lighthouse. If a ship traveled thousands of light-years to the center of the Milky Way, it would reach Sagittarius A*, a supermassive black hole. There, extreme gravity bends light itself, warping the visual field into a distorted ring of glowing gas and stretched background stars.

Where is liquid found in the solar system?

 

To the few places in the solar system like Earth or Titan, the moon of Saturn, where we know liquids exist on the surface, we can now add Pluto. We found evidence of liquid nitrogen flowing on its surface.

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Pluto is very frigid at -232 degrees Celsius. This is below the temperature at which nitrogen can stay liquid, especially since Pluto’s atmosphere is tenuous with very low pressure. However, the interior is probably warmer, and pressure at the base of solid-state nitrogen glaciers provides some heat.

The iconic heart-shaped feature on Pluto is called Sputnik Planitia and is composed of such glaciers. The New Horizons mission was launched in 2006, and it took 9 years to perform the first-ever human flyby of Pluto. In 2015, it sent us invaluable images and data.

Upon recent reexamination, researchers found evidence of liquid nitrogen flowing at the base of glaciers on Sputnik Planitia in the recent past. Pluto now joins the few places in the solar system with evidence of liquid on the surface.

Earth has water oceans; Titan, the moon of Saturn, has seas and lakes of hydrocarbons; there are similar water streaks on Mars as on Pluto; there are geysers on Enceladus, the moon of Saturn, and Triton, the moon of Neptune; and there are lava flows on Io, the moon of Jupiter. Additionally, many moons of gas and ice giant planets and planetoids like Ceres in the solar system have subsurface oceans or pockets of brine

Is gold older than the solar system?

 If you're wearing a gold ring, you're wearing the shrapnel of dead stars. Every atom of gold on Earth is older than the Solar System itself.

The Earth, the Sun, and all the planets in our cosmic neighborhood formed about 4.6 billion years ago from a vast, swirling cloud of gas and dust known as the solar nebula. But that nebula did not manufacture heavy elements; it simply gathered what was already drifting through space.

To understand why gold predates our solar system, it helps to look at how the universe creates elements. The Big Bang produced mostly hydrogen and helium. The intense heat and pressure inside the cores of ordinary stars can fuse these lighter elements into heavier ones, stopping at iron. The formation of elements heavier than iron—like gold, platinum, and uranium—requires an environment far more violent and energy-dense than a standard stellar core.

These precious metals are forged through a mechanism called the rapid neutron-capture process. This occurs during the universe's most catastrophic events: the explosive death of a massive star in a supernova, or the collision of two incredibly dense neutron stars. During a neutron star merger, the influx of free neutrons allows atomic nuclei to rapidly bulk up before they can undergo radioactive decay, synthesizing vast quantities of heavy elements in a matter of seconds.

An artist's impression of two dense neutron stars merging and exploding as a kilonova. This event creates the extreme conditions required to forge heavy elements like gold. Photo by University of Warwick and Mark Garlick is licensed under CC BY 4.0.

The gold forged in these ancient cosmic collisions was violently expelled into the interstellar medium, drifting through the galaxy for millions or billions of years. Eventually, this debris mixed with the hydrogen and helium of the solar nebula. When the nebula collapsed to form our solar system, the gold was already there—a relic of catastrophic collisions that took place billions of years before the Sun even ignited.

How and why doesn't our solar system attract with a black hole, as we know we have millions of them in one galaxy?

 The Milky Way contains up to a billion black holes, but they aren't cosmic vacuums. If the Sun were replaced by one of equal mass, Earth's orbit wouldn't shift a single millimeter.

A black hole does not possess extra gravity just because it is a black hole. Its gravitational pull behaves exactly like the gravity of any other object in the universe with the same mass, provided the object remains outside the event horizon.

If a black hole took the Sun's place, the planet would freeze, but it would continue on its exact current path. Black holes only consume matter that crosses the event horizon. They do not pull distant objects out of stable orbits.

Having millions of black holes wandering the galaxy sounds like a minefield until you account for cosmic scale. The Milky Way is about 100,000 light-years across and contains between 100 billion and 400 billion stars. Even at the high estimate of one billion black holes, they account for less than 1% of the massive objects in the galaxy.

The solar system is not sitting still. The Sun, the Earth, and all those millions of black holes are moving together, orbiting the center of the galaxy in a relatively stable pattern. Because everything swirls in the same general direction, and because space is mostly empty, objects rarely cross paths.

The closest known black hole to Earth is Gaia BH1, which sits about 1,560 light-years away. If the entire solar system out to Pluto were scaled down to the size of a US quarter, Gaia BH1 would still be hundreds of miles away.

A virtual reality simulation of a supermassive black hole and its glowing accretion disk. Photo by European Southern Observatory (ESO) is licensed under CC BY 4.0.

Have there always been 9 planets in our solar system or did more exist at one time ?

We just found stronger evidence for yet another planet. It was a super-Earth that fell into the Sun when the solar system was young.

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This is in addition to the Neptune-sized planet that was between Saturn and Uranus and was ejected.

Planets initially form in the protoplanetary disk from gas and dust, but as they grow larger, more and more massive rocks and eventually planetoids collide to contribute to their mass. This process ended for Earth when the Mars-sized planet Theia collided with it, forming the Moon.

There might also have been a huge world the size of Neptune between the orbits of Saturn and Uranus, and it was ejected. Some earlier studies linked this event to the Late Heavy Bombardment around 3.8 billion years ago. In this model, ejecting this planet disrupted asteroids and comets, which rained down on the remaining worlds, including Earth. However, more recent research suggests the ejection may have happened earlier and may not have been linked to the Late Heavy Bombardment.

This month, computer simulations suggest that the Sun swallowing a super-Earth planet within less than 50 million years after the solar system formed could explain some known anomalies of our star.

The lost planet might have been between 5 and 10 times as massive as Earth, and it enriched the Sun with heavy elements just below the present-day convection zone. This explains its helioseismicity, unusually low lithium abundance, and convection-zone depth. Computer simulations that tried to explain these issues by enriching the Sun with just dust couldn’t reproduce what is observed. Only swallowing a super-Earth planet agrees with these characteristics of our Sun.

Furthermore, we already know that close to 5000 systems with exoplanets and super-Earths are frequent in close orbits to their stars. The existence of a swallowed planet then confirms that our system isn’t unusual; it simply lost such a world early in its history.

How is the solar system traveling? Want to know the details?

 Hurtling at 514,000 mph, the solar system bobs up and down through the galaxy like a carousel horse. The last time Earth was in this exact spot, dinosaurs had just begun to evolve.

The Sun and its planets are in a massive orbit around the supermassive black hole at the center of the Milky Way, located about 26,000 light-years away. It takes roughly 225 to 250 million years to complete one full revolution.

The solar system does not travel completely flat along the galactic disk. The plane in which the planets orbit the Sun is tilted at a 60-degree angle relative to the plane of the Milky Way. As the Sun circles the galactic center, it crosses the midplane every 30 million years or so, oscillating vertically in a path that resembles a wave.

Currently, the overall direction of the Sun's trajectory—known as the solar apex—points roughly toward the star Vega in the constellation of Lyra. As the Sun moves toward this apex, it drags the planets along with it while plowing through the interstellar medium.

This forward motion creates a dynamic interaction with the space around it. The solar wind, a constant stream of charged particles emitted by the Sun, blows outward and forms a protective magnetic bubble called the heliosphere. When this outward pressure meets the gas and dust of interstellar space, it creates a bow wave ahead of the solar system, similar to the water parting at the front of a moving ship. This boundary shields the planets from a significant portion of high-energy cosmic rays as the entire system makes its quarter-billion-year journey around the galaxy.

A scientific illustration of the heliosphere, the magnetic bubble created by the solar wind that shields the solar system as it moves through interstellar space. Source: Wikimedia Commons.

How does our solar system orbit the Milky Way, and why does it take 250 million years to complete one orbit?

 The solar system orbits the Milky Way galaxy at an average speed of about 828,000 kilometers per hour (515,000 miles per hour), taking approximately 230 million years to complete one full orbit around the galaxy's center. This journey is often referred to as a "galactic year."

If you could teleport instantly thousands of light years outside our galaxy and look down upon it with supertelescoping vision you might see something like this:

The Milky Way galaxy spins like water going down a drain with our local group in one arm halfway between the core and the outside edge at a distance of around 27,000 light years.

Our solar system orbits with the Sun dragging the other planets in tow, making the solar system look like it is flying sideways, always moving up since the solar system is tilted that way.

Is the size of a planet or star limited by the laws of physics? Could there be a planet as large as our sun, or a star as large as our solar system?

 Yes, the laws of physics limit the radii of planets and stars (we talk about the radius here because mass is heft, while size means dimensions).

No, there could not be a planet as large as the Sun, using the standard definition of planet (that is, not calling a stellar object a planet just because it orbits another star).

No, there could not be a star as large as our solar system. The largest stars yet observed have radii which may approach that of the orbit of Saturn, around 9-10 AU; in contrast, the radius of our solar system as a whole is more like 100,000 AU.

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Such mega-massive stars sit just beneath the Eddington limit, which is the point at which outward radiation pressure exceeds inward gravitational force. Beyond this, they could not cohere as objects — this is what happens when stars go poof.

Stars like this (St2-18, say, or UY Scuti) are extremely low-density; their masses do not scale up with their sizes in the way you might intuitively suppose. If the Sun is a solid baseball, then these guys are gas-filled hot air balloons in comparison.

They’re big puffballs of radiation, shining with extreme luminosity but barely holding together gravitationally.

Models are being refined as scientists gather and analyze more data, but we think this maximum size is somewhere near 2,000 R☉. Two thousand times the radius of the Sun is intimidating enough! But poke it with a toothpick and it bursts (so to speak).

UY Scuti has nearly 2K times the girth of the Sun, but that is still nowhere near the radius of the whole solar system.

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The radius of a planet is constrained by the fact that, the more mass you add, the more gravitational compression you get scrunching the thing down smaller, or at least preventing it from expanding into something larger. (So, more mass = bigger planet only up to a point.)

Eventually, if you add enough mass, this compression will ignite fusion and you get a star instead.

Jupiter is fairly typical in radius for a really big gas giant. We have observed some which are larger — often 1.5–2 RJ, and in rare extreme cases perhaps as large as 6 RJ. But when you get that big, it’s possible you’re looking at a brown dwarf. Gas giants don’t get a whole lot bigger than Jupiter unless they’re quite hot (i.e., in close orbit of a star). Otherwise 2RJ could mean something like twenty times Jupiter’s mass, and that’s inviting deuterium fusion.

You can have rocky planets as large as a few Earth radii. But if you doubled the mass of Earth, you would only increase its radius by around 20–30%. Here again, gravitational compression is a limiting factor.

And they call gravity the weakest force! Well, it is, but it utterly dominates at the scale of everyday objects, including suns and worlds.

The True Size of the Solar System’s Largest Volcano Will Shock You.

This is Olympus Mons of Mars, the largest volcano of our solar system… Crazy Large.

Many don’t realise how big we're talking, so here is a comparison with Mount Everest and Mount Loa.

At approximately 25 km, it is three times higher than Mt Everest, which is only 8.8 km high.

Surprised? Let me tell you, this is nothing in front of its size comparison.

It’s almost the size of France with an area of 300,000 km², it's so wide that you wouldn't even know you're on a mountain.

And this large area also means that it is significantly harder to climb Everest than Olympus, mainly because it is a very gradual and wide volcano. Its average slope is only 5%.

But why does it even exist?

Except for the fact that possibly it once had lava flows 100× bigger than Earth’s, the most important reason is Mars’s gravity. Mars has only 38% of Earth’s gravity, and that allows structures to grow much taller without collapsing under their own weight.

But you know what’s the funny part, our initial understanding about this giant volcano was a “Snow-Capped Mountain”(1870s–1900s). We even named some bright patches Nix Olympica, which literally means “The Snows of Olympus”. It was mainly because of weak telescopes, and its enormous height also made it look brighter than the surroundings, which felt like snow.

And even today, the name is totally wrong; it literally came from a misidentification, which means “snow patch”… it sounds cool though.

Mariner 9 narrow angle camera of Olympus Mons' central caldera. (March 7, 1972)

This image by Mariner 9 aircraft was among the first images to confirm that Olympus Mons was a volcano.

Digital mosaic of Olympus Mons, taken by the Viking 1 Orbiter. (February 1, 2016)

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Sources: science.nasa.gov, reddit.com

And there are hundreds of more interesting facts about this discovery that we can talk about, numerous findings that have improved our understanding of things over the years that we can dive into.

Is the Earth floating, flying, or falling?

 When I was in school, I saw the solar system in a 2-dimensional plane like this:

When we look at the solar system in static 3D, we will definitely think about the existence of a hypothetical invisible field that holds the planets and the sun from falling, called ether, like the animation below:

The view of the existence of ether is actually just an illusion and will change when we include the fourth dimension, namely motion, in the solar system simulation, so it will look like this.

Of course, the solar system's helical motion isn't entirely accurate, as the planets' actual tilt around the sun is 60 degrees. So, the most realistic depiction of the solar system's motion is something like this.

It's very complicated, isn't it?

So, is the Earth floating, flying, or falling? I prefer to use the words "thrown" and "bound" by the sun's gravity, which also moves with the galaxies thrown around in this vast universe.

Perhaps someday this explosion will turn into a Big Crunch, and everything will return to its original state, only to explode again, forming a new universe. And so on, endlessly.

Why do some star systems have Jupiters that are super close to their suns, and why is our solar system different?

 

The funny thing is that our Solar System may in fact be quite average. The problem lies in being able to detect exoplanets at all. The larger and closer a planet is to a star the more likely we are to detect either the wobble of the parent star or change in brightness from the transiting planet. In both cases, being close to the star makes it more likely to be detected since the orbital period is short. It also helps if the planet is large and massive such as gas giants which are really the only ones that can affect a detectable wobble. The larger surface area of gas giants also makes the change in brightness caused by a transit large enough to be detected. Our Sun’s planets, in contrast, would be hard to detect. Jupiter’s period is about 12 years which means it would take that long to see a wooble cause by it and be able cancel out the Sun’s proper motion. It is also how long you would need to wait (assuming the observer’s line of sight aligns with our ecliptic plane) for anyone to notice a repeat of the begining or end of Jupiter’s transit. Saturn would be even worse for detecting a transit since its period is 29 yrs. A Uranus or Neptune transit may be seen only once in a lifetime if at all within either period of 84 yrs and 165 yrs. Smaller planets, because of their proximity to the Sun like Mercury, Venus, Earth, and Mars would transit more often but would be harder to detect. So, it should not be surprising that the vast mayority of the exoplanets detected are Jupiter size.

There is a size comparison of all the planets to the Sun (notice the four large gas giants) in the simulated image below:

Why is Pluto no longer considered a planet?

 The reason that Pluto is no longer a planet is not because of its size. In fact, it passes the test for "size" (mass).

The definition of 'planet' was made more strict. It is as following:

1. Massive enough to be round. Very massive bodies have so much gravity that they crush down any irregular edges towards their centre, and so become ball-like.

2. The primary object orbiting the Sun. For instance, the Moon orbit's the Sun, but it does so by orbiting the Earth. The Earth is the primary object orbiting the Sun.

3. Has cleared it's own orbit. Planets clear their orbits of debris/asteroids (by attracting them with their gravity).

Pluto passes 1 and 2, but has not passed 3. It has not cleared it's orbit of debris.

Objects like Pluto are called Dwarf Planets.

What is the reason for the Sun not being free?

 because even the Sun can’t pay the energy bill to escape the Milky Way.

It's hold in it's place because of the gravitational field of some even bigger star.

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The concept is simple but brutal. You want out? You better be fast enough. Escape velocity is the speed required to break out of a gravitational well and it’s not optional.

• For Earth to escape the Sun it requires around 42 km/s.
• For Sun to escape the Milky Way it needs around 537 km/s (depends on exact position)

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Again it's not that simple because the more massive the object you're trying to escape from, the deeper the well, and the more energy it takes.

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Let’s say you want to knock Earth out of orbit. You’d need to give it a speed boost of 12 km/s to escape Earth's gravity.
To get it out of the Sun’s orbit at least around 42 km/s is needed.

That’s a lot, but now look at Jupiter which is 318 times the Earth’s mass. You wanna knock it off its orbit you’ll need so much energy you’ll blow up your calculator.

Now apply this to the Sun and you’re talking about lifting 1.989 × 10³⁰ kg of mass out of a galactic orbit that’s been spinning for 4.6 billion years.

The energy required isn’t even insane but actually transcendental.

You would need a force greater than anything we’ve seen in the known universe like short of galactic collisions, supernova clusters, or the wrath of a rogue black hole on a bender.

Just like a rocket needs more fuel to carry more weight, breaking gravitational bonds gets exponentially harder with mass.

Like example, to knock Mercury out of orbit, It's possible with god-tier nukes.

To knock Earth out more energy is needed.

For Jupiter we need galactic-level tech.

And the Sun itself we'd need to rewrite physics, or harness energy at Type III civilization levels. (On the Kardashev scale, we haven’t even hit 0.8.)

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Sun is not a prisoner because it's weak.
It's a prisoner because gravity doesn’t care about power, it cares about proximity and mass.

And just like you can’t flinch a mountain with your bare hands, you can’t knock a star off its galactic path without rewriting the entire dance of creation.

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And the funny part is we don’t even know what gravity is 😁😂. We don’t even know how this jail works.

• Is it a curve in spacetime?
• A field?
• A hypothetical graviton particle?
• A leak from extra dimensions?

We observe gravity. We measure its effects.
But we still don’t understand what causes it at the fundamental level.

These rules are still an unsolved riddle wrapped in tensor equations and unsatisfied physicists.

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Till then Sun is just another inmate in a multilevel cosmic prison.
It burns. It rages. It illuminates life.
But it’s stuck.
Not by choice, not by failure but by the same rule i.e. the rule of gravity that traps galaxies, black holes, and photons.

Freedom, in this universe, has a price.
And the Sun can’t afford it either.

How Big is the Sun Compared to Earth?

 

Have you ever looked up at the Sun and wondered just how big it really is compared to our planet? We know it’s massive — it lights up our days, fuels life on Earth, and governs the motion of planets. But when you dive into the actual numbers, the scale becomes almost unbelievable.

Let’s Start with Diameter

Earth’s diameter: ~12,742 km

Sun’s diameter: ~1,391,000 km

That means the Sun is about 109 times wider than Earth.

Now imagine placing 109 Earths side by side… and you’d just match the width of the Sun.

Now Think in Volume

Here’s where it gets even crazier:

You can fit approximately 1.3 million Earths inside the Sun if it were hollow and you could pack the Earths in like marbles.

Let that sink in — 1,300,000 Earths!

A Visual Comparison

If we scaled it down to everyday objects:

If the Sun were a basketball, the Earth would be the size of a sesame seed.

That’s how small we are in comparison.

Why is the Sun So Huge?

The Sun is a G-type main-sequence star, mostly made up of hydrogen and helium. Its enormous size allows it to generate immense pressure and temperature in its core, where nuclear fusion takes place — the process that powers the Sun and emits the energy we see as sunlight.

A Gravitational Giant

Due to its size and mass, the Sun contains about 99.86% of the total mass of our entire solar system. That’s why all the planets — including Earth — orbit around it.

Final Thought

Understanding the size of the Sun isn’t just about numbers — it gives us perspective. We live on a small planet, orbiting a massive star, in just one corner of a vast galaxy. And yet, here we are, thinking, learning, and exploring it all.