Planet speed is measured and calculated by what instrument

Answer 1

The speed of a planet is typically measured and calculated using instruments such as:

1. Telescopes: Ground-based and space telescopes can observe planets and track their positions over time. By measuring the change in position against fixed stars, astronomers can calculate their speed.

2. Astrolabes: Historical instruments that measure the positions of celestial bodies. Although less common now, astrolabes were used to calculate the speed of celestial bodies, including planets.

3. Radar: For planets in our solar system, radar can bounce signals off planets like Venus or Mars, allowing scientists to accurately determine distances and velocities.

4. Photometry: This technique involves measuring the brightness of a planet and its motion across the night sky to calculate its speed.

5. Spectroscopy: By analyzing the light spectrum from a planet, astronomers can determine its speed based on the Doppler effect. This is useful for studying planets in other solar systems as well.

Overall, modern astronomy heavily relies on sophisticated computer software and models in conjunction with observational data from these instruments to calculate the speeds of planets.