5 Most Incredible Discoveries of the Week Including 2 captivating images from space By Newser Editors, Newser Staff Posted Oct 10, 2015 5:47 AM CDT 0 comments Comments This image released by NASA shows the blue color of Pluto’s haze layer. (NASA/JHUAPL/SwRI via AP) (Newser) – Gruesomeness at an ancient Aztec site and an odd placebo phenomenon make the list: Pluto Has a Blue Sky, Like Ours: A color image of Pluto's atmosphere shows the dwarf planet with a blue glow, suggesting it has a sky similar to Earth's. "Who would have expected a blue sky in the Kuiper Belt?" says a NASA scientist. "It's gorgeous." The color of the planet's ice is a little odd, too. Going to Bed Late Could Be Making You Fat: Want to lower your chances of gaining weight? Then maybe cut out before Jimmy Fallon's opening monologue. Researchers looking at more than 3,300 adolescents between 1994 and 2009 found a two-point BMI increase for every hour later a subject stayed up on weeknights. They've got more bad news for those who think they can compensate by sleeping in. Something Weird Is Happening With Placebos in America: Figure this one out: The fake drugs we know as placebos seem to be getting more effective in the US. A survey finds that people who take the sham medication in medical studies today report more pain relief than those who took them in studies 25 years ago. Higher expectations might be part of the reason. India's Glowing Border Is Visible From Space: An astronaut above the International Space Station has captured a stunning image of what NASA refers to as "one of the few places on Earth where an international boundary can be seen at night." The image shows the glowing, snaking border between India and Pakistan. Click to see the pic. Aztec Site Reveals Grisly Fate of Captured Spaniards: The inhabitants of an Aztec-allied town east of Mexico City reacted with apparent amazement in 1520 when they captured a convoy of about 15 Spaniards, 45 foot soldiers, and 350 Indian allies of the Spaniards. According to artifacts found at the Zultepec-Tecoaque ruin site, a gruesome ritual took place after the prisoners were captured, one of the Spanish conquistadors' worst defeats in Mexico. Click to read about more discoveries, including insights about the giraffe's signature neck.