THE SOLAR SYSTEM
What is the solar system?
There are multiple ways that the boundaries of the solar system are defined but generally it consists of the star at the center that we call the Sun (derived from the Latin word Sol, hence the term solar system) and the numerous planets, moons, asteroids and comets that are gravitationally bound to it. It is only one among hundreds of billions of star systems within the Milky Way galaxy but, for the foreseeable future, humans leaving the solar system remains in the realm of science fiction. Luckily for us, it is a relatively big and complex region of space full of fascinating objects and phenomena.
THE FORMATION OF THE SOLAR SYSTEM
As with all others like it, the solar system formed from the gravitational collapse of a massive cloud of gas and dust, called a nebula. The high abundance of gold and uranium within the Sun, relative to other stars, suggests that the Sun’s formation originated from the remnants of a supernova, the explosive death of a high-mass star where these heavier elements were likely synthesized.
As the massive nebula gradually contracted under its own gravity over millions of years, matter started to coalesce into numerous dense cores scattered throughout. One of these would become our solar system. At the densest point of this region, an object would begin to form, hungrily swallowing up the gas and dust around it, growing and growing until its gravity was strong enough to cause it glow hot from the intense pressure. This was a protostar, our Sun in its infancy.
As the infant Sun consumed and grew, the surrounding material would have began to churn around it in all directions. The paths of trillions of rocks and boulders would have constantly crisscrossed and collided. Over time, these violent clashes would have developed a dominant flow, and the surrounding sphere of debris and dust would have flattened out into a disk with the shrouded infant Sun at the center. Within this cosmic vortex of gas and dust, the collisions would have accrued mergers upon mergers of rocks
TAKING A TOUR OF THE SOLAR SYSTEM
We are privileged to live amongst such a diverse array of fascinating celestial objects.
Note: At the end of each planet’s section is a subsection on that planet’s natural satellites.
The shining, celestial jewel at the center of the solar system.
The closest planet to the Sun.
Earth’s lead-melting twin sister.
The cradle of humanity.
The crimson planet.
The rocky, fragmented halo dividing the planets.
The king of the planets.
The ringed wonder.
The coldest planet.
The furthest planet from the Sun.
The icy, orbital outskirts of the solar system.
Frozen vagabonds that blaze through the night sky.
Wonderous worlds that brave the perilous reaches of the solar system.
THE FATE OF THE SOLAR SYSTEM
The Sun is roughly halfway through its main sequence phase. Over time, the Sun will continue to steadily fuse the hydrogen in its core into helium. However, its fuel supply will eventually deplete. A shell of fusion hydrogen will form around the inert, helium-filled core.
The Sun’s core is not hot or dense enough to fuse helium as much. Without sufficient thermonuclear fusion, there is no longer the same outward pressure to counteract the inward gravity. The Sun will contract, the core will squeeze and heat up even more which will trigger the fusion of helium into heavier and heavier elements. The increased energy from fusion will cause the outer layers of the Sun to expand. This is the beginning of the end.
It is expected that this expansion will reach over 200 times the Sun’s current radius, obliterating Mercury and Venus and possibly even reaching the Earth’s orbit. Whatever in the inner solar system isn’t vaporized, will be reduced to burning cinders. However, the intense radiation will render Earth completely uninhabitable long before it too is consumed. As the Sun expands, it will spread its energy over a larger surface area, which has an overall cooling effect on the star. This expansion and cooling will shift the sun’s visible light to a red color—becoming a red giant.
Planetary nebula
White dwarf