July Night Sky


The sky never reaches astronomical darkness during July in Northumberland.  As you can see from the star chart this is unfortunate because the brightest regions of the Milky Way are now above the horizon.  Better opportunities to see the Milky Way will come during August and September.

The big events of this month are the lunar eclipse on July 27th and the perihelic Mars opposition (also on the 27th).

After sunset there are three bright planets to see.  Brilliant Venus is the brightest and visible low in the west for an hour or so after sunset.  It is approaching its greatest angular distance from the Sun but from the UK it is getting lower in the sky and setting nearer to sunset each evening.

Jupiter can be found fairly high in the southwest and Saturn – not so bright – is low in the south as civil twilight ends.  Both planets are spectacular through the eyepiece of even modest telescopes.  The rings of Saturn are something to behold right now – they are presented at their widest possible angle at present.  They’ll begin closing up over the next few years.

Mars can be found in the southeast shortly after sunset.  The planet reaches opposition on July 27th and is positioned directly opposite the Sun on that date.  The planet is best seen around local midnight (1am BST) when it is highest in the sky.  This is a perihelic opposition of Mars; an opposition which occurs when the planet is near its closest point to the Sun (and therefore – the Earth).  Perihelic oppositions of Mars occur every 15-17 years and provide great opportunities to see surface details on the martian disk with smaller telescopes.

The downside with these oppositions is that they occur when Mars is far south of the celestial equator.  Look at the star chart!   Mars is in Capricornus, near the border with Sagittarius.  At best the Mars is still less than 10 degrees above the southern horizon at midnight.  These are challenging conditions to observe Mars and you’ll need a bit of luck with steady seeing to get good views of the planet this year.  Mars will be a little further away at the next opposition (in 2020) but a lot higher in the Northumberland sky.

Anyway…I’ll post more about Mars and the stars and constellations in our summer night sky over the next few weeks.

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