The James Webb Space Telescope will experience intense forces as it launches into space. To ensure that the different parts of the observatory won’t suffer damage during this stage of the mission, engineers shake them rigorously. These two- to three-week-long vibration tests are performed on each of Webb’s 18 primary mirror segments and the secondary, tertiary, and fine-steering mirrors. Engineers test the mirror’s optics before and after each vibration test to confirm that the simulated launch left the mirror surface unscathed, without deformation or structural changes.... Read More إقرأ المزيد | Share it now!

Backyard stargazers get a monthly guide to the northern hemisphere’s skywatching events with “Tonight’s Sky.” In December, Mars and Saturn are morning planets, and look for the M103 cluster in Perseus.... Read More إقرأ المزيد | Share it now!