The Far Side of the Moon

First, it’s important to know that we always see the same side of the Moon from Earth’s surface—what we call the “near” side of the Moon versus the “far” side of the Moon. 

This is because the Moon’s orbital period is the same as its rotation around its axis. Our planet’s satellite is tidally locked to Earth, which means it rotates on its axis at the exact same rate that it orbits Earth. 

 Discoving the Far Side of the Moon

On October 4,1959, Russia’s Luna 3 spacecraft was launched towards the Moon, where it later became the first vehicle to send back the very first images of the Moon’s far side.

Surprise!

The far side looks a lot like the near side. But not exactly.

• Like the side of the Moon we see, the far side of the Moon is also lit up by the Sun or it’s in shade. It’s not “dark” just because we can’t see it. Every part of the Moon has both day and night in half–month intervals. 
   
• On the near side, we see large, dark seas of cooled lava, called maria, that cover a substantial fraction of the surface. But this lava is absent on the far side which, instead, features many impact craters—scars received during its first few hundred million years of life.
  
  We now know that 35% of the Moon’s Earth-facing hemisphere is covered with molten material, but only 1% made it to the far side. The far side’s crust is also significantly thicker than the near side, perhaps due to the number of impact craters.

Image: First Photo of the Lunar Farside. Credit: NASA.

Seeing the Far Side 

Since 1959, several missions by NASA and other space agencies have shown us more of the Moon’s far side. 

In December of 1968, the Moon’s far side was finally seen with human eyes by the crew of Apollo 8 during their historic circumlunar flight.

Image: Rough terrain on the lunar far side photographed by Apollo 8. Credit: NASA.

Below is another image of the fully-illuminated far side of the Moon that is not visible from Earth. These were captured by NASA’s DSCOVR satellite on July 15, 2015. Twice a year, the satellite is about to capture images of the Moon and Earth together as its own orbit crosses the orbital plane of the Moon. 

On the far side, you can easily see the Mare Moscoviense (Sea of Moscow) and the Tsiolkovskiy crater. Many features on the far side of the Moon retain the Russian names given to them by Soviet scientists.

Note that the Earth’s North Pole is toward the upper left, based on the angle of the satellite’s camera.

The Far Side or the Dark Side?

Apologies to Pink Floyd: There is no continually dark “side” of the Moon.

Both near and dark sides have the “phases” of the Moon with the same cycle of illumination.

Here’s a fun fact:  It’s our near side of the Moon that actually reflects less light than the far side because our side has lots of dark, smooth, low-lying plains (from ancient seas of molten magma) that do not reflect the light as well.

So, the near side is the dark(er) side!  Click here to read about the “Near Side of the Moon.”

Below are images of the Moon. The near side is on the left/top and the far side is on the right/bottom Which side looks darker to you?

Tips on Viewing the Moon

Look at the near side yourself! If you have binoculars, look at the Moon during dusk before the Moon is too bright in the dark sky. You should be able to see those dark lunar lowlands.

The best time to see the Moon is not during the full Moon. It’s easiest to see during the Moon’s crescent or gibbous phase. See my post on the Quarter Moon.

Check your local Moon Calendar to know tonight’s Moon phase.