A rare annular solar eclipse.
Credit: NASA
Under UV light, body parts of the ornate jumping spider fluoresce, and excite the opposite sex's mating interest.
Credit: Science/AAAS
~ Becky Crew
Yes, January 26 is Australia Day, but for those of you who are looking for something a little more scientific to celebrate today, here are a few things I managed to dig up:
• Today marks the 1,946th anniversary of the 5th recorded perihelion passage of Halley's Comet. Derived form the Greek words 'peri' (meaning 'near') and 'helios' (meaning 'sun'), the perihelion is the point in an orbit of a planet, asteroid or comet at which it is the nearest to the Sun.
Observed by astronomers since at least 240 BCE, this plucky little comet makes its way in and out of the inner Solar System every 75 to 76 years, and in 1986 became the first comet to be observed in detail by spacecraft. Oh but don't load some new batteries in your camera just yet - the next perihelion is predicted to occur on 28 July 2061.
• 26 January marks the birthday of Hungarian endocrinologist Hans Hugo Bruno Selye, who demonstrated the existence of biological stress in 1936. Rather than mental stress, biological stress describes the body's reaction to anything from food deprivation and the injection of a foreign substance into the body to a really tough muscular workout.
In 1934, poor old Selye thought he'd discovered a new hormone after having injected ovarian extracts into mice to observe a range of bodily reactions to the foreign matter. "You may well imagine my happiness!" he wrote, obviously jinxing himself. "At the age of 28, I already seemed to be on the track of a new hormone." It was only after he injected the mice with other organ extracts including kidney and spleen extracts that he realised the bodily reactions of the mice were exactly the same. Still, discovering the body's universal reaction to a range of challenging situations is not bad for a 28-year-old.
• On 26 January 1990, an annular solar eclipse could be seen over Antarctica and the South Atlantic. While a regular solar eclipse occurs when the Moon passes between the Earth and the Sun, blocking the image of Sun for eclipse-watchers on Earth, an annular solar eclipse occurs when the Moon's visual diameter is smaller than the Sun. Named after the Latin word 'annulus', which means 'little ring', an annular eclipse causes the obscured sun to look like a colossal burning ring in the sky. Annular eclipses are the rarest form of eclipse and are dangerous to look at with the naked eye.
• And finally, on 26 January 2007, researchers from Singapore published an article in Science reporting for the first time the effcts of ultraviolet light on the sex lives of the ornate jumping spider (Cosmophasis umbratica), an oddly beautiful, iridescent species from India. In UV light, both the males and the females have patches on their bodies that fluoresce, prompting mating pairs to perform courtship rituals involving flexed abdomends and arched legs. In typical girl fashion, sometimes the females will run away briefly if she likes the look of a fluorescing male.
