As NASA marks the 50th anniversary of the Apollo 11 Moon landing, here are five things to know about the Moon that you can share with others.

Night Sky: July 2019

What Can You See This Month?

The Moon takes center stage. For those wishing to view the Moon on the 50th anniversary of the Apollo 11 landing, July 20, the waning gibbous Moon (just four days past full) will rise a little before 10 p.m. local time.

What's Up for July? NASA is celebrating the 50th anniversary of the Apollo 11 mission making the first human landing on the Moon, while looking forward to the future of lunar exploration.

So this month, a special edition of What's Up: Here are five things about the Moon that you can share with others when you're gazing up at our natural satellite.

Illustration showing distance between Earth and Moon is 250,000 miles or about 400,000 kilometers. Illustration showing all the major planets together in a line between the Earth and the Moon.

Earth-Moon Distance

The true distance from Earth to the Moon is farther than people often think. You could just about fit all seven of the other major planets between Earth and the Moon. Credit: NASA/JPL-Caltech

How far away is the Moon?

The Moon is farther away from Earth than people often think. A good ballpark number to remember is that the Moon is about a quarter of a million miles away, or about 400 thousand kilometers. It's such a big gap that you could just about fit the other seven major planets into the space between the two worlds.

Astronauts from three of the Apollo missions, including Apollo 11, placed special reflectors on the lunar surface that are still used to determine the Moon's distance with extreme precision. In fact, they've revealed that the Moon is moving away from Earth by about an inch and a half per year.

Illustration showing a map of the United States covering most of the Moon's near side.
Credit: NASA/JPL-Caltech

How big is the Moon?

This one's another easy approximation to remember: The Moon is about one-fourth the size of Earth in diameter. It's just about as wide as the United States.

What color is the Moon?

The Moon doesn't emit its own light — it reflects light from the Sun. And up close, the Moon's surface is mostly gray, like old, well-worn asphalt.

Chart showing the Moon and Jupiter near the Moon on July 15.
Sky chart showing the position of the Moon, Saturn and Jupiter on July 15, around 10 pm local time. Credit: NASA/JPL-Caltech

Why do we always see the same side of the Moon?

Now it may not look like it, but the Moon really does rotate on its axis, much like Earth. We always see essentially the same face of the Moon because it orbits around Earth in the same amount of time it takes to rotate. The reason is related to gravity and the same forces that cause daily ocean tides.

A side note is that, since it's rotating, there really is no permanent dark side of the Moon. The changing phases of the Moon demonstrate how the portion of its surface that's lit by the Sun revolves around the Moon every month, over the course of the lunar day.

What are the dark areas on the Moon?

One of the main things you notice when observing the Moon is that it has these bright and dark areas across its surface. (Everybody's familiar with the "Man in the Moon," right?)

The dark areas are known as "mare," the Latin word for seas. The lunar mare are volcanic basins created in the aftermath of ancient impacts billions of years ago. After the impacts, the craters filled with lava, which eventually cooled to form smooth, dark plains.

One of the most famous mare is the Sea of Tranquility. This was the landing site chosen for Apollo 11, in part because it was fairly smooth and level.

Picture of Moon with Sea of Tranquility and Apollo 11 landing site marked.
This image of the Moon shows the locations of the Sea of Tranquility (darkened area right of center) and the Apollo 11 landing site (red dot inside the white circle). Credit: NASA/JPL-Caltech

To locate the Sea of Tranquility, look for these two large, dark markings that overlap. If you're facing south, they'll be on the Moon's right side. Tranquility is the lower of the two, and the Apollo 11 landing site is right here.

50 years on, NASA continues to reveal the Moon's secrets, with an eye toward sending the next human astronauts there in the near future.

Here are the phases of the Moon for July.

Moon phases July 2019: New Moon on July 2, first quarter on July 9, full Moon on July 16 and last quarter on July 24.
Credit: NASA

You can learn more about Apollo and NASA's future plans for the Moon at

I'm Preston Dyches from NASA's Jet Propulsion Laboratory, and that's What's Up for this month.

Observing the Moon in July 2019

For those wishing to view the Moon on the date of the Apollo 11 landing anniversary, July 20, the waning gibbous Moon (just four days past full) will rise a little before 10pm local time.

More about the Moon:

About Apollo 11

Apollo 11 patch showing an eagle landing on the Moon.
Apollo 11 Insignia. Credit: NASA | › More on the Apollo Mission Insignias

The goal of Apollo 11 was to land astronauts on the Moon and return them safely home. Considered one of humanity's greatest achievements, the mission conducted the first crewed landing on the Moon, deployed instruments, took photographs, collected samples and returned the crew safely back to Earth.

NASA's Lunar Reconnaissance Orbiter spacecraft has repeatedly imaged the Apollo landing sites, including Apollo 11. The LRO website includes neat interactive called a "flip book" that lets you smoothly slide between the different LRO images, seeing the sites at different times in the lunar day. Try it at

More about the Apollo 11 mission:

More about the Apollo program:

More about the Apollo 50th Anniversary:

Additional Resources

Educational events and activities for the Apollo anniversary:

Additional astronomy & skywatching info from NASA's Night Sky Network:

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