Over the coming weeks we will feature, in no particular order, each of the final 16 selected images and winners will be announced by Royal Museums Greenwich on 17 September. The winning images are to be showcased at the Royal Observatory Greenwich in an exhibition opening 18 September.
In 1884, a delegation of international representatives convened in Washington, D.C. to recommend that Earth’s prime meridian marking zero degrees longitude should pass through the Airy Transit Circle (ATC) at the Royal Observatory in Greenwich, England. But according to the GPS receivers of surveyors and smartphones of London tourists today, why does the line of zero longitude run 102 metres east of the ATC?
In this Hubble Space Telescope image we see an irregular dwarf galaxy known as UGC 4459, located in the constellation of Ursa Major (The Great Bear). While UGC 4459’s diffused and disorganised stellar population of several billion sounds impressive, this is small when compared to the 200 to 300 billion stars in the Milky Way.
According to a team of astronomers led by Dr. Keith Bannister of CSIRO Astronomy and Space Science Division in Australia, invisible noodle- or shell-shaped plasma structures could be floating around in the Milky Way. These structures, which focus and defocus radio waves from distant sources such as quasars, could radically change our ideas about the Galaxy’s interstellar gas.