Engineers tested the world's largest digital camera.
The device takes pictures with a resolution of 3200 megapixels. To display such a photo without compression would require 378 ultra-high-definition television screens with 4K resolution.
The new camera has enormous sensitivity to light: it can detect a candle flame from a distance of thousands of kilometers. The ability to distinguish small details is also impressive: the system will “see” a four-centimeter ping-pong ball from a distance of 25 kilometers.
The device will be the heart of an 8.4-meter telescope under construction known as the Vera C. Rubin Observatory. This tool will be installed in Chile.
The camera is planned to be fully assembled by mid-2021. So far, engineers have assembled and tested its sensitive part containing light sensors (CCD matrices).
This installation is more than 60 centimeters wide and consists of 189 individual sensors. Each sensor has a resolution of 16 megapixels, like a regular modern digital camera. Moreover, individual pixels are very small: about 10 micrometers wide.
The sensors are assembled into 21 blocks of 9 pieces. The gaps between adjacent blocks are only five times wider than a human hair. Because these dies are very fragile, installing them so close to each other was a risky operation. The blocks could easily fail if they accidentally came into contact with each other. Meanwhile, each of them costs three million US dollars (about 228 million rubles at the current exchange rate).
That is why specialists spent a whole year perfecting the procedure for installing sensors. And everything went brilliantly. 21 blocks that form the image, and four more special blocks for adjusting the telescope, took exactly their assigned places. By the way, the entire structure is extremely precisely aligned: all sensors lie in the same plane with an accuracy of up to a tenth of the thickness of a human hair.
To test a camera that doesn't yet have a lens, experts resorted to a clever trick. They projected light through a hole with a diameter of 0.15 millimeters. The objects of observation were specially selected photographs.
Among them was a portrait of the outstanding astronomer Vera Rubin, after whom the telescope was named. This woman became famous for her studies of the movement of galaxies. In particular, her discoveries became one of the first observational evidence of the existence of dark matter.
In the study's press release, the resulting images are shown in full resolution. By gradually increasing the resolution (in this case, an ever smaller part of the image will be displayed on the screen), you can even see traces of light diffraction.
Tests confirmed the unique qualities of the device.
“These characteristics are simply amazing,” admits project collaborator Steven Ritz of the University of California, Santa Cruz. “These unique features will enable the implementation of the ambitious scientific program of the [Vera] Rubin Observatory.”
The challenges facing the instrument are truly enormous. It is planned that in one frame the installation will cover an area of the sky that is 40 times larger in area than the full Moon (most professional telescopes have a much narrower field of view). The observatory will only need a few nights to capture a complete panorama of the southern sky.
Meanwhile, she will conduct continuous observations for ten years. During this time, about twenty billion galaxies and a huge number of other objects will fall into the frame. Also, quick images of large areas of the sky will provide a unique opportunity to track flares of a wide variety of natures, from supernova explosions to the destruction of stars by black holes. It is still difficult to imagine what discoveries such extensive observational data will bring.