Xenon occurs naturally in the Earth's atmosphere as a trace gas. It is found in very small amounts, making up only about 0.087 parts per million by volume.

Here are some more details:

* Atmospheric origin: Xenon is a noble gas, meaning it's chemically inert and doesn't readily react with other elements. This makes it stable in the atmosphere, where it remains trapped.

* Formation: It is believed to have originated from the Earth's mantle and crust through radioactive decay of heavier elements.

* Extraction: Xenon is extracted from the atmosphere by a process called fractional distillation of liquid air.

While it's primarily found in the atmosphere, traces of xenon can also be found:

* Natural gas: Some natural gas deposits contain small amounts of xenon.

* Groundwater: Dissolved xenon can be found in groundwater.

It's important to note that xenon is a rare element, making its natural occurrence in any form quite small.