Why is the first photo of Mars sent back by Tian Wen-1 black and white?

It can be learned from the website of NASA that at 20: 00 on February 5, 2002 1, China's Mars probe requested1to ignite the engine, and the modification of the fourth track of the eastern geochemical profile was successfully completed. This is to be able to capture Mars as planned. As of February 5th, Astronomy-1 was about 6,543.8+0.84 million kilometers away from the Earth, 6,543.8+0,654.38+0 million kilometers away from Mars, with a flight mileage of about 465 million kilometers, and all systems of the detector were in good condition.

Then this photo was taken about 2.2 million kilometers away from Mars. It was an attempt to photograph Mars, and it was also the first time that China photographed Mars in space. In the photo, Mars landmarks such as astoria Plain, Chris Plain, Zhao Plateau, Schia farrelly Pit and Mariner Valley are clearly visible. But Mars should be orange or red. Why are all the photos taken in China black and white? Is the camera level in our country not good? In fact, there is a lot of knowledge in it.

This time, our imaging mode is black and white, so the photos are black and white. It is easy to understand that this photo is black and white. 2.2 million kilometers is a long distance. It's hard to shoot. The camera installed a few days ago is not designed for ultra-long-distance shooting. The main task is to obtain fine observation images of key areas on the surface of Mars. These two imaging detectors are expected to obtain true color fused images and video images of the surface of Mars. These two cameras are respectively a medium resolution camera MRC with a 400km high orbit resolution of 100m and a high resolution camera HRC with a 400km high orbit resolution of 2m. Their HRC performance is comparable to that of HRSC high-resolution stereo cameras equipped with Mars Express detectors by European Space Agency, and their comprehensive technical indicators have reached the highest level in the world. This is not the first photo shoot. It's July 27th, 2020. Astronomy 1 about1.2000 km from the earth. This is not the first time it has taken photos of the Earth and the Moon with optical navigation sensors.

Optical navigation sensor is the eye of spacecraft and an important part of astronomical navigation system. According to the principle of optical detection in the universe, sensors need to collect spacecraft attitude or navigation information, which can provide accurate pointing or position information for space tasks such as remote sensing measurement, weapons and aiming, scientific observation and deep space exploration. Optical navigation sensors can image reference targets such as planets, small celestial bodies and X-ray pulsars, and realize relative direction and autonomous navigation. They can be used to guide the autonomous navigation and target approach of detectors in interstellar flight, rather than the ground measurement system. Therefore, optical navigation sensors generally do not require high image resolution or color imaging. Because there are other heavy jobs.

Finally, it should be emphasized that the photos of the universe taken by humans are actually black and white, and the color photos we see are actually post-PS. Scientists first take photos with different frequencies with cameras, then dye them separately, and then stack them layer by layer to make color photos. Because each substance has its own spectrum, dyeing is actually looking for colors in every field of black and white photos.