Molecular clouds are vast and fascinating structures in space, playing a crucial role in star formation. They are characterized by several key properties:
Here's a breakdown of their characteristics:
Size and Mass
- Vast Extent: Molecular clouds are enormous, typically spanning about 150 light-years across.
- Significant Mass: They contain a substantial portion of the total mass found within the interstellar medium.
Density and Temperature
- Relatively High Density: Compared to the average density of the interstellar medium, molecular clouds are denser, with an average density of 100 to 300 molecules per cubic centimetre.
- Extremely Cold: The internal temperature within molecular clouds is very low, ranging from only 7 to 15 Kelvin (K).
Composition
- Gas and Dust: Molecular clouds are primarily composed of gas and dust.
- Stellar Nurseries: Although composed of gas and dust, molecular clouds often contain many stars as well, as they are the birthplaces of stars.
Summary of Molecular Cloud Properties
| Property | Description |
|---|---|
| Size | ~150 light-years across |
| Mass | Contains a large portion of interstellar medium mass |
| Density | 100-300 molecules/cm³ |
| Temperature | 7-15 K |
| Primary Composition | Gas and dust, also contains stars |
In essence, molecular clouds are immense, cold, and relatively dense regions in space, composed mainly of gas and dust, and are the sites where stars are born.
