In 2017, two solar eclipses crossed the planet. Millions were awestruck as the earth, moon, and sun aligned, casting watchers into total darkness. America experienced the most extensive total eclipse, lasting ninety straight minutes, visible along a path pinpointed by NASA scientists.
Now that we’re done with the planets, asteroid belt, and comets, we’re heading to the outskirts of the solar system. Out past Neptune are vast reservoirs of icy bodies that can become comets if they get poked into the inner solar system. The Kuiper Belt is a donut shape aligned with the plane of the solar system; the scattered disk is more eccentric and is the source of short period comets; and the Oort Cloud which surrounds the solar system out to great distances is the source of long-period comets. These bodies all probably formed closer into the Sun, and got flung out to the solar system’s suburbs by gravitational interactions with the outer planets.
From a greenhouse in Holland to a desert landscape in Iceland, scientists are using the earth to tests ways to keep a Mars settlement alive and well. It’s the ultimate survival challenge, requiring major innovations to find water, grow food and clean the air.