Out of Space

Tracking satellites launched from NZ

Duncan Steel Jun 27, 2019

With so many thousand satellites now in orbit, and tens of thousands of other tracked items, one might think that it is difficult keeping tabs on them, simply as an interested person. In fact it is quite straightforward, with long lists of orbital elements freely available for all except the few satellites deemed by the US Government to require secrecy, … Read More

The day the Sun stood still

Duncan Steel Jun 25, 2019

We have just passed the solstice, the shortest day of the year in the southern hemisphere. From now on, the hours of daylight will get longer through until the December solstice. Here I discuss why the June solstice occurs a few days before the Feast Day of St John the Baptist, the traditional time of ‘midsummer’ in the northern hemisphere … Read More

Murchison and geology

Duncan Steel Jun 19, 2019

There are many places, both in New Zealand and elsewhere around the globe, that are named for the nineteenth-century Scottish geologist Sir Roderick Impey Murchison. It seems astonishing how many of these are connected in some way with events of geological significance, or are otherwise of scientific importance.  One of my predilections is writing blog posts prompted by the occurrence … Read More

Astronomy on Bloomsday

Duncan Steel Jun 16, 2019

The name of Michael Faraday is well-known in science, for his pioneering work in both chemistry and physics (in particular electricity and magnetism; hence the name of the SI unit of capacitance, the farad). As a postgraduate student at the University of Canterbury I spent many hours working on experimental radio receivers sat inside a large metallic box … Read More

Connecting comets and rubber

Duncan Steel Jun 11, 2019

Comet Grigg-Skjellerup was one of the first such celestial bodies to be visited by a spacecraft, the Giotto probe which was sent on to encounter it in mid-1992 after having first visited the famous Comet Halley in 1986. Comet Grigg-Skjellerup was discovered about a century ago, independently by a New Zealander (John Grigg) and an Australian (Frank Skjellerup). The younger … Read More

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The problem of knowing when a lunar year begins and ends

Duncan Steel Jun 05, 2019

The Islamic fast of Ramadan has come to an end, marking the beginning of the tenth month of the religion’s twelve-lunation year and therefore Eid al-Fidr, the ‘Festival of Breaking the Fast’. How the decision is made when each of those months begins and ends depends upon the actual sighting of the crescent new moon in the sky, a highly-complicated … Read More

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The 250th anniversary of Cook’s observation of the transit of Venus

Duncan Steel Jun 02, 2019

On June 3rd occurs the 250th anniversary of the transit of Venus across the face of the Sun, the observation of which was the prime purpose behind the expedition of HM Bark Endeavour to the South Pacific, under the command of Lieutenant James Cook. Following the measurements of the transit made by Cook and the mission’s scientists in Tahiti, the … Read More

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The Great Eclipse of 1919

Duncan Steel May 29, 2019

Measurements of photographs obtained during the total solar eclipse of 29th May 1919 were pivotal in demonstrating the veracity of Einstein’s General Theory of Relativity, turning him into a household name. The centenary of that event is now upon us, and well worthy of being remembered.  As I sit here typing on my keyboard, my favourite photo showing myself and … Read More

A new crater on the Moon

Duncan Steel May 21, 2019

The scar on the lunar surface produced when the Israeli space probe ‘Beresheet’ slammed into the Moon on April 11 has just been spotted using an orbiting NASA satellite.  Three nations have so far landed spacecraft on the Moon: the USA, the Soviet Union/Russia, and China. A fourth nation, Israel, has attempted to join this club, but its probe (named Beresheet) … Read More

Talking satellites and space in Washington

Duncan Steel May 16, 2019

The annual beanfeast for the US satellite industry — featuring major participation from European nations and companies in particular — is the SATELLITE congress held at the Washington Convention Center, a few blocks from the White House. It was an amazing event to attend, compared to the sort of low-key conferences we have in New Zealand.  Now I’m back in … Read More