Why Is Space Silent?

One of the most fascinating aspects of space is its silence. This means no one can hear you speak or any other sound outside the Earth’s atmosphere. Even so, being heard should be the least of your worries when outside Earth because you would become unconscious without a space suit within seconds. That aside, for those who have always been fascinated with space sounds, here is a detailed explanation of why it’s silent.

Reasons Why Space Silent

Let’s start by explaining how sound works to better understand why space is silent. Referring back to what was taught in 4^th-grade science class, sound is defined as a wave of energy that flows through gas, liquid, or solids. It is created through vibrations that are transferred through molecules.

People near you can hear what you’re saying because of the transfer of vibrations along air molecules. Though not as fast as light, sound travels at 343 miles per second, which is pretty fast. That’s why face-to-face conversations are so seamless.

A quick look at space’s features reveals it has no molecules or atoms; it’s basically a vacuum. Without molecules or atoms, there is no channel or medium that can be used to transfer sound. No matter how loud you shout, sound won’t be able to travel in any direction.

Also, there won’t be an echo, leading to the famous saying, “No one can hear you screaming in space.” Fans of space movies such as Interstellar and The Martian may have noticed this phenomenon in these films.

How Do Astronauts Communicate in Space?

Because space is silent, astronauts must wear specially-designed communication devices in their suits. They can effectively facilitate sound transfer from the mouth to the communications device for others to listen and reply.

Are The Other Planets Silent As Well?

Now that we are talking about space sounds, it would be unfair to ignore the experience human beings would have on the neighboring planets. On Venus, the air in the atmosphere is thick. As such, human beings would produce a low-pitched and deeper sound.

Should we be able to colonize Mars one day, the thin air would lead to the production of a high-pitched, hollow, and tiny sound that resembles that of a piccolo. Note that these are all hypothetical scenarios because, on a planet such as Venus, human beings would melt immediately when they step foot on the surface because of the extreme temperatures. Also, life on Mars has proven difficult because of the excessive presence of carbon dioxide in the air and the extremely low temperatures.

The Space Might Be Silent, But Not Entirely So

While the general consensus is that the space is silent, it is not entirely so. This is because it’s not a true vacuum; scientists only call it a vacuum because majority of it is empty. However, there is dust, clouds of gas, and a wide range of molecules through which sound can travel.

A perfect example is when NASA released the sound of the black hole at the center of the Perseus Galaxy Cluster in 2022. They were able to capture this sound with the help of the Chandra X-Ray Observatory. It sounds exactly how you think space would sound, a clear indication that most sci-fi movies are perhaps right. The sound was so low-pitched that it couldn’t be heard by the human ear. So, NASA had to use sonification to make it more audible.

Besides the black hole, other bodies in space, such as the sun, and the charged particles it emits can also be used as a sound medium because they contain molecules. That’s not all; plasma and gravitational waves can also provide a medium for transferring sound particles. NASA scientists can capture and listen to these sounds using special radio telescopes.

The Key Take Away

The bottom line is that space is silent, but there are a few exceptions because it’s not a true vacuum. There are specific points where sound has a medium of transfer. Provided there are molecules, sound vibrations will transfer across mediums. Scientists are still researching space sounds, and there is a lot we don’t know about what happens outside the Earth’s atmosphere. This is why astronauts always play it safe by integrating communication devices into their space suits and never leave their space crafts without wearing space suits.