Geomagnetic constellation _ constellation magnetic field

What natural compasses are there (write at least 4)?

The natural compass has the following characteristics: 1. Sun: The sun is one of the natural compasses. In the northern hemisphere, when the needle points to the sun, the south will be behind it. In the southern hemisphere, when the needle points to the sun, the north will be behind it. 2. Stars: Polaris is one of the most important navigation constellations in the northern hemisphere. It is almost located at the zenith of the northern sky, which can help people determine the direction of the north. 3. Geomagnetic field: The magnetic field of the earth itself can also be used as a compass. The geomagnetic field is produced by the movement of the earth's core, and the North Pole and the South Pole are the poles of the earth's magnetic field. The magnetic needle can be used to determine the north-south direction according to the geomagnetic field. 4. bird migration: bird migration can also be used as a reference for a compass. Some birds determine their migration direction according to the earth's magnetic field. This phenomenon is called magnetic induction. Observing bird migration can provide useful clues about directions and seasons.