Here's why:
* Direct measurement is impossible: We can't just use a ruler to measure the distance to a planet. It's too far away.
* Triangulation uses geometry: This technique involves measuring the angle between two points on Earth and the planet. The distance between those two points on Earth is also known. By using trigonometry, we can calculate the distance to the planet.
Here are some specific methods that use triangulation:
* Parallax: This method uses the Earth's orbit as a baseline. We measure the angle to a planet from two points in Earth's orbit six months apart. The difference in angle tells us the distance.
* Radar ranging: This method sends a radio wave signal to the planet and measures the time it takes to return. This gives us the distance because we know the speed of light.
These methods are essential for understanding the vast distances in our solar system and beyond.
