Breathable Outer Space

You're on a typical spacewalk. When your helmet suddenly falls off, you breathe in some crisp cosmic air rather than suffocate. How expansive would the atmosphere of space be. Why would space become so loud all of a sudden? And may this result in the destruction of the solar system as a whole?

This is a what-if scenario, and this is what would happen if outer space was breathable. The air you breathe on Earth is made up of 78 nitrogen, 21 oxygen, and trace amounts of other gases. That molecular oxygen is necessary for life. Beyond the 10,000 kilometers that the atmosphere reaches above the Earth's surface, molecular oxygen is scarce. Oxygen atoms bind with space dust in space. Instead of molecular oxygen, they react with hydrogen atoms to form water ice. But what if we could discover breathing air all the way to the heliosphere's outskirts? That is the point at which the Sun's gravity no longer outweighs that of other stars. Would an enormous atmosphere allow you to travel anywhere in space while still breathing as you do on Earth?

Aside from that unexpected breath of fresh air, you'd learn about some other significant developments. You'd be able to hear the sun and other planets now. Sound cannot travel in space due to the vacuum. This is due to the fact that there are insufficient molecules between the planets and stars to convey the vibrating sound waves. However, in this new space atmosphere, sound waves might travel tremendous distances, allowing you to hear everything loud and clear.

The sun vibrates at various frequencies all the time. It'd be so loud that it'd appear deafening. Even with the immense distance between our star and the Earth's surface, it would reach your ears at 125 dB. Consider going about your everyday routine to the sound of church bells, only hundreds of police sirens louder. This would be inconvenient, but it would not be your primary concern.

There is no friction in the vacuum of space. That means that all of the planets and moons orbit the sun without losing speed, or lose it extremely slowly. However, with outer space now filled with air, all of the planets would collide at tremendous speeds with air particles. The Earth would suffer the same fate as asteroids entering our planet's atmosphere. They heat up and burn as a result of the friction. So, with the Earth currently orbiting the Sun at a speed of 30 kilometers per second, all that friction would result in burnt surfaces. And this would not be the end of the chaos. The moon would eventually come to a complete stop. The Moon would then be drawn closer by Earth's gravity, resulting in a disastrous collision.

If you survived the scorched Earth, this crash would be the end of the world. It would shatter the Earth. With so much air in it, the remainder of the solar system wouldn't fare much better. Our solar system could develop into a black hole. This is due to the fact that all of this air has mass. And with the heliosphere's radius covering 90 astronomical units, that's a lot of mass, roughly 5 billion times more than the sun itself.

If the sun's gravitational force compressed all of this mass toward it, the solar system would grow progressively dense. You'd saw the formation of a black hole if all that air was compressed into a space around 80% the size of the Earth's diameter. That black hole would be around 1200 times more massive than the supermassive black hole in the center of the Milky Way if you were still alive at the time, which is doubtful. You and I would be long gone by this point, which may be for the best because it appears like these two gravitational giants are poised to clash.