How Far Away Is the Moon

Detailed answer

Average distance from Earth to moon

• Average distance: The moon is 238,855 miles (384,400 km) away from Earth on average, which is the typical distance from Earth to moon
• Light travel time: At this average moon distance in miles, light takes approximately 1.28 seconds to travel from the moon to Earth

Orbital variations in how far away the moon is

• Closest approach (perigee): 225,623 miles (363,104 km) from Earth, the shortest distance from Earth to moon
• Farthest point (apogee): 252,088 miles (405,696 km) from Earth, the maximum moon distance in miles
• Orbital range: The moon's distance from Earth varies by about 26,465 miles (42,592 km) throughout its orbit, affecting how far away the moon is at different times

Visual effects of distance variation

• Apparent size: At perigee, when the moon is closest to Earth, it appears 14% larger and 30% brighter than at apogee
• Supermoon: When a full moon coincides with perigee, it's called a "supermoon," appearing slightly larger and brighter than usual due to the reduced distance from Earth to moon

Measurement and scale of moon distance

• Measurement precision: Modern techniques like the Lunar Laser Ranging experiment can measure how far away the moon is with millimeter precision
• Scale comparison: If Earth were a 3-inch diameter orange, the moon would be a ping pong ball orbiting 6.7 feet away, illustrating the relative distance from Earth to moon

Interesting facts about moon distance

• Gradual recession: The moon is slowly moving away from Earth at a rate of about 1.5 inches (3.8 cm) per year, gradually increasing how far away the moon is
• Historical measurement: Ancient Greeks estimated the moon's distance to be around 397,500 km (247,000 miles), which was relatively accurate for their time in determining how far away the moon is

FAQ

How far away is the moon on average?

The moon is 238,855 miles (384,400 km) away from Earth on average. This is the typical distance from Earth to moon that we refer to when discussing the moon's location.

What is the closest distance from Earth to moon?

The closest distance from Earth to moon, known as perigee, is 225,623 miles (363,104 km). This occurs when the moon is at its nearest point to Earth in its elliptical orbit.

What's the farthest distance between Earth and the moon?

The farthest distance between Earth and the moon, called apogee, is 252,088 miles (405,696 km). This happens when the moon reaches its most distant point from Earth in its orbit.

How much does the moon distance in miles vary throughout its orbit?

The moon distance in miles varies by about 26,465 miles (42,592 km) throughout its orbit. This variation is due to the moon's elliptical path around Earth, causing it to move closer and farther away during its monthly cycle.

How long does it take light to travel the distance from Earth to moon?

At the average distance from Earth to moon (238,855 miles or 384,400 km), it takes light approximately 1.28 seconds to travel between the two celestial bodies. This illustrates the vast distance between Earth and its natural satellite.