Today marks a historic day for science. The James Webb Space Telescope has captured its first images, and NASA itself has decided to share the milestone with the world. From its official blog, the National Aeronautics and Space Administration comments that the James Webb “is nearing completion of the first phase of the observatory’s primary mirror alignment process using the Near Infrared Camera (NIRCam) instrument”; a process that has lasted months and is finally nearing completion of its first phase.

Although it is the most advanced telescope in the world, the first images taken by the James Webb will not come as a surprise to those outside the scientific world. However, there is a reason for the apparent simplicity of the image. The imaging process of the James Webb is scheduled to take months; it is a highly complex operation some 1.5 million kilometers from Earth. For this reason, NASA warns us that it is normal that the results in just a few weeks look like white dots on a black background.

As described by NASA in its press release, all 18 points of light belong to the same star. This time, we have the light from the same star reflected in the 18 segments of the James Webb primary mirror. The result, of course, “is an image mosaic of 18 randomly arranged points of starlight; a product of the unaligned mirror segments,” as the agency describes in its release.

According to NASA itself, what now looks like a simple image of blurry starlight becomes the basis for aligning and focusing the telescope in order for Webb to deliver unprecedented views of the universe this summer. Over the next month, the team will gradually adjust the mirror segments until all 18 images become a single star.

The images from the James Webb Space Telescope come from a 25-hour-long effort. During this time, the team behind the telescope pointed their sights at 156 different locations, obtaining some 1,560 images with the NIRCam sensors. For NASA, this translates to about 54 GB of raw data.

Once the images were obtained, the James Webb team set about creating a mosaic using each of the mirror segments in a single image. However, the image published by NASA does not do justice to its original resolution -for clear reasons-; the entire mosaic has a resolution of more than two gigapixels.

The real mission is just beginning

The James Webb Space Telescope is preparing to look back to the dawn of our universe. However, this mission will take quite some time. In the meantime, NASA is expected to unveil the first exciting images of space and all its component elements in June.

So far, the published images show that the James Webb is on the right track; so we just have to be very patient to see the real results of its expedition through outer space.

2 COMMENTS

  1. And you may ask, what celestial object have they chosen to make the alignment? Well, they have chosen the star HD 84406 of apparent magnitude +6.7 located in Ursa Major, near Dubhe, a star from which the JWST has already begun to “see” the first photons.

    It is a G5 type star, therefore yellow like the Sun, although larger, 1.4 solar masses and located 260 light-years from us. It has been chosen because the engineers consider it to be of the right magnitude to perform the alignment and it looks good from Webb at this time of the year. This alignment will last about 3 months, meanwhile, the shadow part of the satellite continues to cool, it is now at -215ºC and should reach -235ºC.

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