methods could allow. Starting around 2000, digital cameras were incorporated into cell phones; in the following years, cell phone cameras became widespread, particularly due to their connectivity to social media and email. Since 2010, the digital point-and-shoot and DSLR cameras have also seen competition from the mirrorless digital cameras, which typically provide better image quality than point-and-shoot or cell phone cameras but are smaller in size and shape than typical DSLRs. Many mirrorless cameras accept interchangeable lenses and have advanced features through an electronic viewfinder, which replaces the through-the-lens viewfinder of single-lens reflex cameras. History While digital photography has only relatively recently become mainstream, the late 20th century saw many small developments leading to its creation. The history of digital photography began in the 1950s. In 1951, the first digital signals were saved to magnetic tape via the first video tape recorder. Six years later, in 1957, the first digital image was produced through a computer by Russell Kirsch. It was an image of his son. The first semiconductor image sensor was the charge-coupled device (CCD), invented by physicists Willard S. Boyle and George E. Smith at Bell Labs in 1969. While researching the metal-oxide semiconductor (MOS) process, they realized that an electric charge was analogous to a magnetic bubble and that the charge could be stored on a tiny MOS capacitor. As it was fairly straightforward to fabricate a series of MOS capacitors in a row, they connected a suitable voltage to the capacitors so that the charge could be stepped along from one to the next. This semiconductor circuit was later used in the first digital video cameras for television broadcasting, and its invention was recognized by a Nobel Prize in Physics in 2009. The first image of Mars was taken as Mariner 4 flew by it on July 15, 1965, with a camera system designed by NASA and JPL. In 1976, the Mars Viking Lander produced digital images from the surface of Mars. The process was different from, but comparable to, a modern digital camera—it used a video camera tube, followed by a digitizer, rather than a mosaic of solid state sensor elements. This produced a digital image that was stored on tape for later slow transmission back to Earth. The first published color digital photograph was produced in 1972 by Michael Francis Tompsett using CCD sensor technology and was featured on the cover of Electronics Magazine.