The streak of light in this remarkable photograph is a "shooting star," a tiny speck of space debris burning up as it enters Earth's atmosphere.
To the naked eye, a shooting star appears as a fleeting flash of white light. This image, however, documents the appearance of a wide spectrum of colors produced by the object as it hurdles toward Earth. These colors are predictable: first red, then white, and finally blue. If the meteor (shooting star) is large enough to survive the fall through the atmosphere, it cools and doesn't emit any visible light at all.
The colors of this shooting star may also indicate the minerals that make up the space rock. Different elements emit different-colored light when they burn. Iron, one of the most common elements found in meteors, glows yellow. Silicates, which contain a form of the element silicon, glow red. A green glow, clearly visible in the trail of this shooting star, indicates the presence of burning copper.
Understanding how, why, and when these colors appear is the science of spectroscopy.
- Iron, which can give a meteor a yellow glow, is frequently used in fireworks to produce a gold color. Copper, which produces a tell-tale green or blue glow in meteors, isn't usually used for fireworks, however. Copper is unstable and difficult to manage at high temperatures.
- Visible light is only a tiny part of the electromagnetic spectrum. A meteorite (or person!) at room temperature on Earth doesn't emit visible light, but they still "glow" in the infrared part of the spectrum. This infrared light is what heat-sensing cameras can display.
- The Draper point is the temperature at which all solids begin to emit a dim, red glow. Below the Draper point, solid materials only "glow" in infrared. The Draper point is about 525 (977, or 798 Kelvin).
Term Part of Speech Definition Encyclopedic Entry atmosphere Noun
layers of gases surrounding a planet or other celestial body.
Encyclopedic Entry: atmosphere copper Noun
chemical element with the symbol Cu.
remains of something broken or destroyed; waste, or garbage.
Draper point Noun
temperature at which almost all solid bodies at room temperature glow a dim red. The Draper point is about 525 Celsius (977 Fahrenheit, or 798 Kelvin).
our planet, the third from the Sun. The Earth is the only place in the known universe that supports life.
Encyclopedic Entry: Earth electromagnetic spectrum Noun
continous band of all kinds of radiation (heat and light).
chemical that cannot be separated into simpler substances.
to give off or send out.
to display or show.
infrared radiation Noun
part of the electromagnetic spectrum with wavelengths longer than visible light but shorter than microwaves.
chemical element with the symbol Fe.
rocky debris from space that enters Earth's atmosphere. Also called a shooting star or falling star.
Encyclopedic Entry: meteor meteorite Noun
type of rock that has crashed into Earth from outside the atmosphere.
Encyclopedic Entry: meteorite mineral Noun
inorganic material that has a characteristic chemical composition and specific crystal structure.
natural substance composed of solid mineral matter.
shooting star Noun
rocky debris from space that enters Earth's atmosphere. Also called a meteor.
most common group of minerals, all of which include the element silicon (Si).
chemical element with the symbol Si.
science of the measurement of light that is reflected, absorbed, or emitted by different materials.
continuous band of material with each piece differing in small amounts from the piece before and after it.
degree of hotness or coldness measured by a thermometer with a numerical scale.
Encyclopedic Entry: temperature visible light spectrum Noun
light and colors that can be seen by human beings.