The Solar System is located inside the “Local Bubble”, which is a cavity in the interstellar medium (ISM) in the Orion Arm of the Milky Way. It contains, among others, the Local Interstellar Cloud and the G-cloud.
“The story so far:In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.”
Douglas Adams, The Restaurant at the End of the Universe
The Universe is all of time and space and its contents. The Universe includes planets, natural satellites, minor planets, stars, galaxies, the contents of intergalactic space, the smallest subatomic particles, and all matter and energy. The observable universe is about 28 billion parsecs (91 billion light-years) in diameter at the present time.Read More
Cosmic dust is dust which exists in outer space. Most cosmic dust particles are between a few molecules to 0.1 µm in size. A smaller fraction of all dust in space consists of larger refractory minerals that condensed as matter left the stars. It is called “stardust” and is included in a separate section below. The dust density in the local interstellar medium of the Local Bubble is approximately 10-6 × dust grain/m3 with each grain having a mass of approximately 10-17 kg.Read More
In astronomy, the interstellar medium (ISM) is the matter that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space.Read More
A planetary nebula is a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.Read More