Astronomy

Perhaps you’ve heard of the popular Netflix show and the science fiction novel on which it is based, The Three-Body Problem, by Chinese science fiction author Liu Cixin. The story’s premise is a star system where three stars orbit each other, which leads to periodic destruction on a planet orbiting one of them. As Isaac Newton described in his Philosophiæ Naturalis Principia Mathematica, the interaction of two massive bodies is easy to predict and calculate. However, the interaction of three bodies leads is where things become unpredictable (even chaotic) over time. This problem has fascinated scientists ever since and remains one of the most famous unsolved mysteries in mathematics and theoretical physics. The theory states that the interaction of three gravitationally bound objects will...

Fig. 1. Rev. Ellison as he appeared on the frontispiece of the 2nd edition of The Amateur’s Telescope Rev. W.F.A. Ellison  Rev. William Frederick Archdall Ellison was the sixth Director of the Armagh Observatory and was appointed to the role on 15 October 1918. He would remain in this position until his death on 31 December 1936. During that time, he made several telescopes and mirrors, both for the Observatory, and to supplement his income, which was very low compared to other Astronomers in the United Kingdom. He had been making mirrors for twenty years when he arrived in Armagh and had built up a reputation as by publishing articles and pamphlets about telescope-making in The English Mechanic and other periodical journals.   Fig. 2. The Ellison Reflector as it appears in The Amateurs Te...

This spectacular ‘Ring of Fire’ eclipse of the Sun took place on 20 May 2012. Image: Kevin Baird. On 2 October one of the most spectacular events in nature takes place. A annular eclipse, popularly described as a ‘Ring of Fire’ eclipse, is visible along an east-to-west orientated path in the far south of South America, crossing Chile and Argentina. Unlike at a total eclipse of the Sun, the Moon’s shadow stops just short of Earth’s surface, leaving a thin band of the Sun’s blinding photosphere encircling the Moon’s silhouette.  A large area of South America experiences a partial eclipse. In Buenos Aires, Argentina, 53.3% of the Sun is hidden by the Moon at 5.23pm. The eclipse takes place between 15:43h and 21:47h UT, with the maximum duration of the annular eclipse lasting seven minutes an...

An asteroid hurtling toward Earth could be deflected without a spacecraft ever touching it. The trick is using X-rays to divert the space rock, researchers report September 23 in Nature Physics. In lab experiments, scientists heated the surfaces of free-falling faux asteroids with X-ray radiation, producing vapor plumes that pushed the objects away. Subsequent computer simulations demonstrated that X-rays emitted by a distal nuclear blast could deflect some asteroids that are about as wide as the National Mall in Washington, D.C., is long. input[type="radio"].svelte-wecxzz{display:none}.payment-option-wrapper.svelte-wecxzz.svelte-wecxzz{display:flex;flex:1 0 28%;width:100%}.payment-option-wrapper.svelte-wecxzz.svelte-wecxzz:only-child{max-width:3...