Radiant stars, glowing planets, colorful nebulae: the universe is often depicted in pictures as a mystical place with many colors. How do these fascinating space images that the "James Webb" telescope has recently been sending to us come about?
The "James Webb Space Telescope", as it is called by its full name, has several instruments on board for this purpose. These record different electromagnetic frequency ranges in the near-infrared range, which are mostly invisible to the human eye.
This data "is stored in a digital format with ones and zeros," says Joe DePasquale on the Nasa Podcast. Essentially it is a black and white picture. The Senior Data Image Developer at the Space Telescope Science Institute in Baltimore (US state of Maryland) and his team are responsible for publishing the space images from the "Webb" telescope, among others.
This data from the telescope must first be cleaned of instrumental effects, explains astrophysicist Kai Noeske from the European Space Agency (ESA). Then comes the colour: Roughly speaking, the primary colors red, green and blue are assigned to different areas.
Because it is not the case that the scientists create an image with the colors they have chosen. DePasquale explains, "We respect the data from start to finish. And we make the data come in color."
The way to the final product - the photo
Objects in space such as stars or gases are visible in different wavelengths. In order to be able to record these, the Webb telescope has several filters on board. Astrophysicist Noeske illustrates the work in the image processing program, where the color comes into the picture: "As a rule, the image in the shortest-wave filter is the blue channel, in the middle filter the green channel, and the image in the longest-wave filter is the red channel."
This approach does not differ too much from normal digital or smartphone cameras in this respect. They also use tricks to depict colors. There, sensors measure the proportions of red, green and blue in the respective image areas. The monochrome image information is assembled into a color image directly in the camera or smartphone.
Conspiracy theorists against science
There is image processing in many disciplines, including microscopy. And yet: when pictures from space are published, conspiracy theorists often feel called onto the scene. They believe, for example, that the moon landing was staged around 50 years ago or that aliens left a human-like face on the surface of Mars. Recently they are also targeting the images of the Webb telescope. Your claim: The pictures are fakes. Why is there no belief here either?
"We often speak of conspiracy ideology when people develop a world view in which an alleged conspiracy is suspected behind everything," explains political scientist Josef Holnburger to dpa. He is one of the managing directors of Cemas (Center for Monitoring, Analysis and Strategy) in Berlin, which monitors, among other things, radicalization tendencies and the spread of conspiracy stories in social media.
These conspiracy ideologies often lead to adopting an anti-everything position, believing, for example, that climate change does not exist, that the earth is actually flat and that mankind has never been to the moon. "All new findings are subordinate to this world view: images from the James Webb telescope must therefore be fake in this world view; precisely because they come from scientists," explains Holnburger. In the world view of a conspiracy ideology, research works together with the alleged conspirators.
The Massachusetts Institute of Technology (MIT) has dedicated a recently published study to the Webb data. The results suggest that the tools currently used to decode light signals may not be sufficient to accurately interpret the Webb telescope data. "Currently, the model (...) does not match the precision and quality of the data available to us from the James Webb telescope," a researcher is quoted as saying in a statement. The current evaluations could be more precise.
The James Webb telescope was launched on December 25, 2021 on board an Ariane launch vehicle. Previously, there had been explosions in costs and repeated shifts. The space agencies of the USA, Canada and Europe are cooperating on the project. Behind it are 30 years of development and costs of around ten billion dollars (around 8.8 billion euros).
The Webb telescope follows the Hubble telescope, which has been in use for more than 30 years. While "Hubble" works in the optical and ultraviolet range, "James Webb" investigates in the near-infrared range.
The "James Webb" telescope provides new images from the early universe with the help of a 25 square meter mirror, among other things. Science hopes the recordings will provide insights into the time after the Big Bang around 13.8 billion years ago - and possibly even evidence of a second earth.