Backyard stargazers get a monthly guide to the northern hemisphere’s skywatching events with “Tonight’s Sky.” In April, Saturn reaches its closest point to Earth, the Big Dipper overflows with cosmic sights, and the Lyrid meteor shower streaks the sky. “Tonight’s Sky” is produced by HubbleSite.org, online home of the Hubble Space Telescope. This is a recurring show, and you can find more episodes — and other astronomy videos — at HubbleSite.org.... Read More

The digital camera in your home shares a family tree with the James Webb Space Telescope. Webb’s instruments use “detectors,” similar to the sensors in digital cameras, to convert images into a digital signal. At the Jet Propulsion Laboratory in California, the detectors are undergoing temperature and vibration testing.... Read More