Google Earth can serve plenty of purposes, and a lot of that comes from the great imagery that you can see of pretty much any place on the planet. Originally the satellite images that you would find in Google Earth and inside of the Satellite layer of the Google Maps app were picked up from the Landsat 7 satellite. Back in 2013, NASA launched the Landsat 8 as a means to replace Landsat 7 and to get higher quality images of the earth. Now, three years later, Google has begun to use these new higher quality images to replace the ones that were being used in Google Earth and Google Maps.
Not only are these new satellite images higher quality than the ones used before, but images like the ones below are cloud free thanks to Google's method of stitching together the clearest pictures to get this result, which, Google notes they had to look at millions of images before arriving at this point. While cloud free images are definitely a huge improvement, it isn't the only change as Landsat 8 images are also a lot sharper as you can see from the last two images in the gallery below that are comparing the exact same picture with one being from Landsat 7 and another being from Landsat 8.
In addition to providing a sharper image quality, Landsat 8 provides double the amount of images as it captures twice as much as Landsat 7 in a single day, and it delivers truer colors. Taking all of the data captured from Landsat 8, Google has compiled the imagery into their best global mosaic yet. Google mentions that getting higher quality images was not the only reason for NASA launching Landsat 8, as there was a hardware failure back in 2003 which cause the satellite to malfunction, which resulted in a series of diagonal lines of lost data that would appear in the images. Google states that they used the same Earth Engine APIs that are available to the public and which are used by scientists for mapping global surface water of a period of three decades to put together the global mosaic. Users will be able to see all the new imagery which is a compilation of some Landsat 7 images but mostly Landsat 8, in all of Google's mapping products.