The distances between the various celestial objects are usually expressed in the unit of :

Options

A. kilometres
B. light minutes
C. light years
D. light seconds

Answer

To determine the unit used to express the distances between various celestial objects, we can follow these steps:

### Step 1: Understand the Context
We need to identify the appropriate unit for measuring astronomical distances. Celestial objects include stars, planets, and galaxies, which are often very far apart.

**Hint:** Think about how we measure large distances in space compared to distances on Earth.

### Step 2: Evaluate the Options
We have four options to consider:
1. KM (Kilometers)
2. Light Minutes
3. Light Year
4. Light Second

**Hint:** Consider which of these units would be practical for measuring vast distances in space.

### Step 3: Analyze Each Option
- **KM (Kilometers):** While kilometers can be used for distances on Earth, they are not practical for astronomical distances due to the vastness of space.

- **Light Minutes:** This unit measures the distance light travels in one minute, but it is still relatively small for astronomical measurements.

- **Light Year:** This is the distance that light travels in one year. Given the speed of light is approximately 300,000 kilometers per second, this unit is suitable for measuring large distances in space.

- **Light Second:** Similar to light minutes, this unit measures the distance light travels in one second, which is also not practical for astronomical distances.

**Hint:** Think about which unit would allow astronomers to express distances that are much larger than those typically encountered on Earth.

### Step 4: Conclusion
After evaluating the options, the most suitable unit for measuring the distances between celestial objects is the **Light Year**.

**Final Answer:** The distances between various celestial objects are usually expressed in the unit of **Light Year**.