Yes, there are terrestrial and solar examples of Lyman alpha emissions, and they are associated with specific phenomena:
Terrestrial Examples:
Planetary Auroras: Auroras are natural light displays in the Earth's sky, mostly seen in high-latitude regions near the magnetic poles. They are caused by the interaction of charged particles from the solar wind with the Earth's magnetic field. When these charged particles collide with the gases in the Earth's atmosphere, they can excite the atoms, and as the atoms return to their lower energy states, they emit light. In some cases, the emission of Lyman alpha radiation (wavelength around 121.6 nanometers) can be observed in the auroral displays. This Lyman alpha emission is caused by the excitation and de-excitation of hydrogen atoms in the upper atmosphere.
Incandescent Spectral Lines: In certain high-temperature environments, such as flames, incandescent light bulbs, or hot gases, spectral lines can be observed in the emitted light. These lines correspond to specific wavelengths of light that are characteristic of the atoms or molecules present in the hot environment. While hydrogen's Lyman alpha line is particularly prominent in celestial objects like stars, in terrestrial environments, it is usually overshadowed by other emission lines from different elements. However, in specialized experiments or in certain laboratory conditions, the Lyman alpha line of hydrogen might be observed.
Green Flash: The green flash is a rare optical phenomenon that occurs just before sunrise or just after sunset when a sliver of the sun is visible on the horizon. It appears as a brief green light that lasts for a fraction of a second. The green flash is caused by the Earth's atmosphere acting as a weak prism, dispersing sunlight into its various colors. The green flash is primarily due to atmospheric refraction and is unrelated to Lyman alpha emissions.
Solar Example:
- Solar Lyman Alpha Emission: The Sun emits a considerable amount of Lyman alpha radiation, which is a type of ultraviolet (UV) light with a wavelength of approximately 121.6 nanometers. This radiation originates from the outer layer of the Sun's atmosphere, known as the solar chromosphere. The Lyman alpha line is an important diagnostic tool for studying the Sun's atmosphere and is commonly used in solar physics research.
In summary, Lyman alpha emissions are observed in certain terrestrial phenomena, such as planetary auroras and high-temperature environments, but they are more prominently associated with solar physics and the Sun's emission of Lyman alpha radiation from its chromosphere.