Weird giant barcodes can be seen from the skies across the US

If you've ever flown above the US and looked down, you might have happened upon some strange sights.

The look like giant barcodes - and no, they're not for aliens going shopping from above.

Instead, these unusual geometric shapes serve a very useful purpose.

According to The Center For Land Use Interpretation (CLUI), they're 'aerial photo calibration targets' and were mostly made during the 1950s and 60s.

So what do they actually do? Well, they help align the lenses on aerial and satellite cameras.

If you were looking at them from the ground, they'd look like big strips of black or white paint onto concrete or asphalt.

These strips come in all different sizes - and there's an important reason for that.

"The targets function like an eye chart at the optometrist, where the smallest group of bars that can be resolved marks the limit of the resolution for the optical instrument that is being used," notes the CLUI.

"For aerial photography, it provides a platform to test, calibrate, and focus aerial cameras traveling at different speeds and altitudes. The targets can also be used in the same way by satellites."

So sadly nothing to do with aliens (that we know of).

Most of these curious targets are found in California's Mojave desert - and as they're the work of the Air Force and NASA, many are found near air bases.

In fact, according to the CLUI, the largest collection of calibration targets in one place is around Edwards Air Force Base in Kern County, California.

But we'll apparently never really know just how many of these targets are. Many sit in restricted areas, meaning that even a good hunt on Google Earth won't reveal anything.

It's not the first time something strange has popped up on Google Earth - there's even a TikTok account with 5.7 million followers dedicated to uncovering hidden sights on the satellite map system.

One of the top posts zooms in on something particularly creepy-looking - a circle made of stones, with some eerie white structures next to it.

But as is often the case, all is not quite as it seems.TikTokers have flooded the comments with the actual truth: it's a look at the Goldwell Open Air Museum in Nevada and its outdoor works of art, which suddenly seems a whole lot less threatening.