Slate: Normally, I think pictures of Earth from space are among the most beautiful of all astronomical photos. Our home is gorgeous, especially when seen from afar.
But Monday, NASA tweeted a picture of our world whose ugliness made me literally gasp when I understood what I was seeing.
The photo above is from the Earth-observing DSCOVR satellite, which sits 1.5 million km (almost a million miles) over our planet, taking full-disk images every hour, which are then put online for the public to view....