Image description: The flight mirrors for the James Webb Space Telescope undergo cryogenic testing at NASA Marshall.

Photo by Ball Aerospace.

Image description: Camelopardalis, or U Cam for short, is a star nearing the end of its life. As stars run low on fuel, they become unstable. Every few thousand years, U Cam coughs out a nearly spherical shell of gas as a layer of helium around its core begins to fuse. The gas ejected in the star’s latest eruption is clearly visible in this picture as a faint bubble of gas surrounding the star.

Image from ESA/NASA

Image description: NASA astronaut Joe Acaba captured this photo of the southern lights from the International Space Station in July.

You can read more about this and his other experiences in space on The Great Outer Space: Astronaut Joe Acaba blog.

Image description: NASA’s Cassini spacecraft delivered this view of Saturn while the spacecraft was in the planet’s shadow. Learn more about this view of Saturn.

Image from NASA/JPL-Caltech/Space Science Institute

Image description: Ball Aerospace’s Jake Lewis is reflected in one of the mirrors on a James Webb Space Telescope.

Photo by David Higginbotham and Emmett Given, NASA.