We think of tattoos as fixed adornments. But tattoos are maintained by an ever-changing process — one in which ink crystals are continuously engulfed, regurgitated and gobbled back up. French scientists saw that macrophages — immune cells that ingest foreign debris in the body — descend to capture invading ink as a tattoo is given. With time, the original macrophages die and release their pigments, which get vacuumed up by new macrophages, starting the cycle over. Targeting these cells might help improve tattoo removal procedures.
A hot ticket: Your name flown by sun
NASA will fly you to the sun — or at least your name. Now until April 27, NASA is accepting online submissions for this summer’s Parker Solar Probe mission, which will come within 4 million miles of our star, closer than any other spacecraft.
White rhino moves closer to extinction
The beleaguered northern white rhinoceros moved closer to extinction with the deteriorating health of the only surviving male of the species. The 45-year-old rhino, named Sudan, made headlines last year after it was dubbed “The Most Eligible Bachelor in the World” on Tinder as part of a campaign to spread awareness about rhinos. Technically, the species is classified as extinct because it no longer exists in the wild, conservationists said. Barbara Durrant of San Diego Zoo Global said, “The loss of a population, especially of a mega vertebrae like a rhino is a significant loss in terms of genetic diversity.”