Space Photos of the Week: Mooooooon Shadow, Moon Shadow

NASA has big plans to go back to the moon, so the first order of business is to look into lunar locations where resources are accessible. One of those prime spots is its southern pole, where water ice is hidden in shadowed craters. This black and white photo, taken by NASA’s Lunar Reconnaissance Orbiter, shows the Shackleton crater in the center—one of several craters in the south that is permanently in shadow and likely contains a large amount of water ice.

Mars goes technicolor in this elongated image. This stretch of land is the plains between Chryse and Acidalia Planitias, which like so much of Mars has a pretty active past. The darker blues indicate basaltic rocks, formed during the region’s violent volcanic history; the oranges are formations created by the wind, and as such are called windstreaks. You can even see how the material has been lifted up around the crater and pushed south.

In February, comet C2018 Y1 Iwamoto flew past the Earth some 56 million miles away. The Neowise space telescope captured it in infrared with four different exposures, which is why it appears in the image as a series of red smudges. The hotter stars appear blue here, whereas the colder dust and ice from the comet are rendered in red.

This is a “preplanetary” nebula called the Egg Nebula. And it has nothing to do with eggs or planets, despite its name; it was created by a dying star shedding its outer layers. These kinds of nebulae exist in this state for only a few thousand years as they evolve into planetary nebulae. The dark bands and jutting white arms are material left over from a star that was not very different from our Sun. Once the expiring star (hidden from view in the center by dust and debris) eventually stops spitting out material, its remaining core heats up. Then the surrounding gas gets excited and set aglow and transitions into a planetary nebula, which again has nothing to do with planets; the name comes from its shape.

This photo has a lot going on, so let’s break it down: First, that vertical band of starlight is an arm of our Milky Way, and those telescopes are called the Four Unit telescopes at the European Southern Observatory’s Very Large Telescope in Cerro Paranal, Chile. Also note the bright orange laser pointed toward the sky: That’s used as a guide star to calibrate the telescope. By pointing the laser up, researchers can tell how turbulent the atmosphere is and can better prepare for a night of observing.

Messier 3, how you sparkle! Astronomers adore this globular cluster, and it’s no mystery why: It’s one of the most massive ever discovered in our universe, containing a whopping 500,000 stars. Many of those stars are variable stars, which vary in brightness, and a good number are newer and more luminous stars called blue stragglers. They all were formed at more or less the same time, 8 billion years ago.

social experiment by Livio Acerbo #greengroundit #wired