Friction generated by the atmosphere
Explanation
Meteoroids are small rocky or metallic bodies traveling through space. When they enter Earth's atmosphere, they do so at extremely high velocities, often ranging from 11 km/s to 72 km/s.Detailed Analysis:
- Intense heat from the Sun is incorrect: The heat from the Sun is relatively constant in the vicinity of Earth and does not cause the sudden vaporization observed during atmospheric entry.
- Collision with other celestial bodies is incorrect: The phenomenon is not caused by collisions with other distinct celestial bodies (such as moons or asteroids) but by interaction with the Earth's gaseous envelope.
- Friction generated by the atmosphere is correct: As the meteoroid travels through the atmosphere at hypersonic speeds, it encounters significant air resistance. This interaction generates immense heat due to friction and the rapid compression of air gases in front of the object (ram pressure). This heat causes the meteoroid to glow and vaporize, creating a streak of light known as a meteor or "shooting star."
- Internal chemical reactions is incorrect: The heat is generated externally through physical interaction with the atmosphere, not by internal chemical instability or spontaneous reactions within the meteoroid itself.
Key Takeaway: The incandescence of a meteor is primarily caused by the conversion of kinetic energy into heat energy due to atmospheric friction and gas compression.