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.
On 18 June at the end of civil twilight in the UK, planets Mars and Mercury lie slightly less than one-quarter of a degree apart in the constellation of Gemini. Observing this conjunction will be a challenge from the UK as the pair will be just 5 degrees high in the west-northwest at civil dusk in bright twilight, which is about 50 minutes after sunset for London.
The prestigious Insight Astronomy Photographer of the Year competition is an annual celebration of the most beautiful and spectacular visions of the cosmos by astrophotographers worldwide. Now in its seventh year, the 2015 competition received 2700 spectacular entries from over 60 countries and the winners will be announced 17 September.
While truly massive stars go out in a blaze of glory, intermediate-mass stars — those between roughly one and eight times the mass of the Sun — are somewhat quieter. Such stars eventually form cosmic objects known as planetary nebulae, so named because of their vague resemblance to planets when seen through early, low-resolution telescopes.