4 ms·
Apparently the Diffraction spikes come from both the primary mirror shapes and the struts holding the secondary mirror. The primary mirrors of the JWST are hexa
by WorldMaker 4y ago
Apparently the Diffraction spikes come from both the primary mirror shapes and the struts holding the secondary mirror. The primary mirrors of the JWST are hexagonal which would explain hexagonal looking effects. The three struts are apparently designed so that two of the struts match the hexagonal mirror angles at all times and are "hidden" inside. (The third strut apparently sometimes causes two much smaller "horizon" spikes for very, very bright objects.)
Hank Green on TikTok did a neat, quick demonstration in video form.
- mintyLemon 4y agoLink to that Hank Green video on YouTube: https://m.youtube.com/watch?v=Y7ieVkK-Cz0 https://m.youtube.com/watch?v=Y7ieVkK-Cz0
- loxias 4y agoThe hero we need. Thanks!
- andai 4y agoThese these two pages have some nice visualizations of the optical phenomena: https://blogs.nasa.gov/webb/2022/02/03/photons-incoming-webb-team-begins-aligning-the-telescope/ https://blogs.nasa.gov/webb/2022/02/03/photons-incoming-webb... https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/
- hackernewds 4y agoah an authoritative source. if only we funded scientific exploration more heavily with public funds..
- dr_orpheus 4y agoOh, thank you that makes sense. And due to the folding of the mirror and launch envelope constraints they can't equally space the three struts such that ALL are inside the diffraction of the hexagonal mirror.