Six months ago, I wrote about the Russian weather satellite Elektro-L, which has more than two years of successful experience in the geostationary orbit. Then I promised that I would be here to share the materials that we collected. I think it's time to deliver on the promise.
Here it is: the view from Saturn of our Earthly home, one and a half billion kilometers away. We see Earth and the Moon through a thin veil of faintly blue ice crystals, the outskirts of Saturn's E ring. Earth is just a bright dot -- a bit brighter than the other stars in the image, but no brighter than any planet (like Saturn!) in our own sky.
The fictional world Tatooine, scene of action in the Star Wars movies, is named after a town in Tunisia, where parts of the movies were filmed. The desert backdrops against which the movies were filmed are real terrestrial landscapes, which prove to be perhaps unexpectedly dynamic.
It had never occurred to me to think about geostationary satellites in Mars orbit before reading a new paper by Juan Silva and Pilar Romero. The paper shows that it takes a lot more work to maintain a stationary orbit at an arbitrary longitude at Mars than it does at Earth.
I'm absolutely floored when I stop to think that our beautiful blue ocean is only one of perhaps a half dozen or more oceans on other worlds in our solar system, and only one of probably millions (or more) oceans on other Earth-like planets in our galaxy. Oceans abound!