This Mountain On Mars Is Leaking
As the midsummer Sun beats down on the southern mountains of Mars, bringing daytime temperatures soaring up to a balmy 25ºC (77ºF), some of their slopes become darkened with long, rusty stains that may be the result of water seeping out from just below the surface. Seasonal flows spotted by HiRISE on northwestern slopes in…
Beyond “Fermi’s Paradox” II: Questioning the Hart-Tipler Conjecture
It’s become a legend of the space age. The brilliant physicist Enrico Fermi, during a lunchtime conversation at Los Alamos National Laboratory in 1950, is supposed to have posed a conundrum for proponents of the existence of extraterrestrial civilizations: If space traveling aliens exist, so the argument goes, they would spread through the galaxy, colonizing…
Why Do We Have Allergies?
Allergies such as peanut allergy and hay fever make millions of us miserable, but scientists aren’t even sure why they exist. One master immunologist is offering up a controversial answer. But first, some personal context: for me, it was hornets. One summer afternoon when I was 12, I ran into an overgrown field near a…