The world's largest astronomical digital camera was unveiled at Stanford Linear Accelerator (SLAC) National Accelerator Laboratory under the US Department of Energy! According to a recent report on the website of New Scientist, this camera is 1.65 meters high, higher than a car, and has 3.2 billion pixels. In the next decade, it will help scientists study billions of galaxies to better reveal the nature of dark matter. As part of the "Space and Time Heritage Survey" (LSST) project, this camera, called "LSST Camera", will be installed at the Vera Cooper Rubin Observatory at the top of Cerro Pason Mountain in Chile at the end of 2024, and will photograph and catalog about 20 billion galaxies in the next decade. This observatory is named after astrophysicist Vera Cooper Rubin to commemorate her important contributions in the field of dark matter research. Researchers pointed out that this camera will collect tens of terabytes (TB, trillion bytes) of data every night, improve people's understanding of the universe, help researchers reveal the nature of mysterious dark matter, and better understand how galaxies are formed. The working principle of LSST camera is the same as that of any other digital camera, but its volume is much larger. 189 sensors are installed on it, which can receive the light from stars and other objects, and convert it into electrical signals, so as to convert it into digital images. Each sensor is about 16 mm in size and contains more pixels than an iPhone. Overall, the digital camera has 3.2 billion pixels and can take extremely high resolution images - enough to see the dust particles on the moon. Moreover, the largest lens on the digital camera has a diameter of 1.57 meters, which is the largest lens of its kind so far. Vincent Leot, LSST camera project manager, said that in 2020, before installing any lens or shutter on the camera, SLAC researchers had tested the sensor. Now all other permanent components have been installed in place. The camera will undergo strict testing for five months to avoid troubleshooting after moving to the mountain top. (Liu Xinshe)