What is in the Space Between Planets?
The space between planets, known as interplanetary space, isn't truly empty. It contains a surprising amount of material, though it's incredibly diffuse compared to the planets themselves.
Interplanetary space is primarily composed of:
- Neutral hydrogen: Extremely small amounts of this are dispersed throughout.
- Plasma gas: This is electrically charged particles originating from the Sun, forming the solar wind.
- Cosmic rays: High-energy particles from outside our solar system.
- Dust particles: Microscopic particles of rock and ice.
These components exist in a near-vacuum, meaning the pressure is extremely low. While seemingly empty, this space isn't devoid of matter entirely. The density of these materials varies depending on location within the solar system and solar activity.
Distances and the Perception of Emptiness
The vast distances between planets contribute to the perception of emptiness. As one reference notes, the distance between planets changes constantly as they orbit the Sun. (If the Moon Were Only 1 Pixel - A tediously accurate map of the solar ...) This makes pinpointing the exact composition at any given time difficult, but the general components remain consistent.
Another resource highlights the challenge of quantifying the “stuff” in interplanetary space, referencing examples like asteroid fields which could affect the amount of material between planets (How much 'stuff' is in space between the Earth and Mars? : r ...).
What it's Not
It is important to note that the interplanetary medium is not a simple void. Some sources mistakenly refer to it as “nothing,” but the presence of the aforementioned components disproves that notion. (In outer space, what does space actually consist of between planets ...)
