What is a primary energy source for auroras at Earth?

What is a primary energy source for auroras at Earth?

• A. Geothermal heat from Earth's core
• B. Solar wind energy interacting with Earth's magnetic field
• C. Radioactive decay
• D. Comet impacts

Answer: (B)

The energy powering auroras comes from the solar wind—the stream of charged particles flowing from the Sun. When these particles reach Earth, they interact with the planet’s magnetic field and transfer energy into the magnetosphere. This energy accelerates and channels particles down along magnetic field lines toward the polar regions, where they collide with atoms in the upper atmosphere and cause them to light up as they return to their ground state. The other sources—heat from Earth’s interior, radioactive decay, or comet impacts—do not provide the sustained, directed energy input needed to produce auroras, so they aren’t the primary source.

The energy powering auroras comes from the solar wind—the stream of charged particles flowing from the Sun. When these particles reach Earth, they interact with the planet’s magnetic field and transfer energy into the magnetosphere. This energy accelerates and channels particles down along magnetic field lines toward the polar regions, where they collide with atoms in the upper atmosphere and cause them to light up as they return to their ground state. The other sources—heat from Earth’s interior, radioactive decay, or comet impacts—do not provide the sustained, directed energy input needed to produce auroras, so they aren’t the primary source.