The Sky Above You – July 2021

By Duncan Lunan

The Moon will be New on July 10th, and Full on July 24th.  On the morning of July 6th the waning crescent will pass between the Pleiades and Aldebaran, the brightest star in Taurus, closest to it on the 7th.

The planet Mercury returns to the morning sky and is at greatest distance from the Sun on the 4th, but will be more visible in the third week of July, rising at 4 a.m..  The Moon is near Mercury on the 8th.

Venus now sets at 10.30 p.m. (BST), passing the Open Cluster Praesepe in Cancer on the 2nd and 3rd, but low down in the evening twilight and visible only with binoculars or a telescope.  Venus is passed by the Moon on the 11th.  Venus has been moving towards Mars, and will be closest to it on July 12th, half a degree apart, below and to the right of the waxing crescent Moon which passed them the previous night.  Because of recent discoveries concerning Venus, NASA has decided to send two new probes there in the late 2020s, rather than launching possible new missions to Jupiter and Neptune.

Mars in Leo passes close to Regulus on July 29th, but is now very hard to find in the early evening sky, disappearing as the month goes on.  NASA’s Ingenuity helicopter has now completed its planned test programme on Mars and is scouting ahead of the Perseverance rover in Jezero Crater, for as long as it can.  China’s Zhurong rover landed successfully and is exploring a flat plain in Utopia.  Viking 2 was intended to land at a similar site there in 1976, but instead came down in a boulder field ejected from a small crater, very like the Viking 1 landing site in Chryse. 

Jupiter in Aquarius rises at 10.30 p.m., closest to the Moon on July 25th.  NASA’s Juno probe has made a close pass of Ganymede, the largest moon in the Solar System, in the first such visit for 20 years.  As the Earth passes through Jupiter’s orbital plane, in July there will be multiple transits across the face of the planet  by Jupiter’s large Galilean moons and their shadows – see the July issue of Astronomy Now for details. 

Saturn in Capricornus rises at 10 p.m. by the end of the month, and is also passed by the Moon on the 24th.

Uranus inAriesrises at 1 a.m., 11.45 p.m. by the end of the month, near the Moon on the 4th.

Neptune rises in Aquarius at 11.30 a.m., near the Moon on the 27th.

Like last month, it will never be completely dark during July, as the Sun never gets far below the horizon.  It’s a good time to see noctilucent  (night-glowing)  clouds in the north, lit by sunlight at high altitudes, first reported in the 19th century and still not fully explained.

The Scottish Dark Sky Observatory

The really bad news from Ayrshire this month is the total destruction by fire of the Scottish Dark Sky Observatory, apparently deliberate, on Wednesday June 23rd.  The building (opened in 2012)  was burned to the ground, and as its creator Mark Gibson said, “My dream turned to dust”.  Other founders are equally devastated.  Even for me there’s a personal loss, because I had donated my collection of star charts and other memorabilia to the Observatory’s historic collection;  others who donated irreplaceable historic instruments are equally affected.  It had been made clear that I could borrow back items if I needed them, and I had intended to do so for an exhibition last year, taking the opportunity to make a permanent record of them, which didn’t happen due to Covid and will never happen now.

To their credit, within hours the Trustees had issued a statement that they would not be beaten by it.  The building and instruments were fully insured and they have already begun planning their replacement, once the police investigation is over.  Benefiting from the experience of the last nine years, their intention is to make the reborn Observatory single-storey, more accessible to the public, and particularly to cater more for disabled access. 

Donations can be made at:

.Duncan Lunan’s space travel stories, old and new, are available from Other Side Books as From the Moon to the Stars, relating to the Moon and Project Apollo, and The Other Side of the Interface, with a wider scope.  Both have illustrations by Sydney Jordan, and are available through Amazon or through bookshops.  For details and for his other books see his website,

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