Look south at the end of the night and the brightness of Mars will impress you: this planet had not been so bright for nearly 15 years!
Don’t miss March! Its brilliance has just surpassed that of Jupiter and, after Venus sets at the beginning of the night, Mars becomes the brightest point star in the night sky. The planet is clearly visible to the naked eye in the second part of the night and at dawn in the south of the sky even in the middle of the city, even in an environment degraded by light pollution. This summer, Mars is almost twice as bright as in its previous opposition in 2016. It was shining then in the Milky Way, but it has since moved towards Capricorn and therefore now appears on a less richly starry sky background, which further enhances its intense and obviously orange glow.
Observe the southern sky region in the second part of the night and at dawn to see for yourself how spectacular the brightness of the planet Mars has quickly become. It may take an effort in this summer period (in the Northern Hemisphere) when dawn begins more than two hours before sunrise, but it is really worth it because our little neighbour is now brighter than Jupiter, the giant planet of the Solar System. Only Venus is even brighter, but she goes to bed early in the evening and leaves Mars free. Of course, we cannot see any detail on the planet with the naked eye, we need a telescope for that, Mars remains a simple luminous point on the celestial vault, but a luminous point of a rare intensity whose orange colouring is obvious and whose strange fixity magnetizes the glance: the minute movements of the Earth’s atmosphere which make the stars sparkle are swallowed up and erased by the apparent diameter of this star whose brilliance increases each day more.
This increase in Martian brightness is caused by the decrease in the distance that separates us from this planet as we approach its opposition. Like two cyclists who would run at full speed on a huge track whose centre would be occupied by the Sun, the Earth, which travels in a smaller orbit, is getting ready to catch up with Mars by rope and is getting several hundred thousand kilometres closer to it every day. The orbit of Mars being more elliptical than that of the Earth, its distance from the opposition can vary between less than 60 and more than 100 million kilometres all oppositions are therefore not equal and that of this year is exceptional.
By the end of July, the Sun, Earth and Mars will be aligned: the Earth-Mars distance will be 57.6 million kilometres, the smallest separation since September 2003, and the brightness of the Martian point will have been multiplied by a factor of 1.4 compared to today. We are thus entering this very particular period for the planet Mars where the rapid increase of its rubescent brilliance makes it a really special star. A star that even people who don’t usually take the time to look at the sky notice in the night by raising an interrogative eyebrow. And this is all the easier as Mars rises earlier and earlier, rising above the southeast horizon a little before midnight now and gaining a few minutes each evening to rise just after the Sun disappears at the end of the month.
As in the spring of 2016, Mars will have an appointment with the full moon during its opposition. The meeting, which will take place on July 27, will however be much more spectacular since the Moon will be totally eclipsed and Mars will be much brighter than on this image; read this post to know more.
In ancient times, periods of Martian opposition were watched with fear because they had been associated with the evils – wars, epidemics, famines – that struck human societies. Unfortunately, human history has always been sufficiently rich in such events that it has been easy to claim that some of them occurred during, or even because of, the bursts of Martian brilliance; hence the bad reputation of this small planet which bears the name of the god of war, impetuous, cruel and bloody son of Zeus and Hera in Greek mythology. Even today, some might be tempted to see the bad influence of Mars/Arès in the impetuous and cruel actions of another rubicond character who threatens the balance of the world. However, it is only a planet, which the interlocking cycles of celestial mechanics regularly highlight and which I invite you to observe with complete serenity.
Like these last summers, I propose a more personal text to conclude this post. I wrote it during the previous exceptional opposition of the planet Mars and it was published in my book Night Notebooks.
A night in the Cévennes
In the blue sky crows swim. They stir the air with their generous wings and tear the delicate evening fabric of their vulgar croaking. The night creeps into its indentations, spreads inexorably, filling the deep and bushy Cevennes valleys, overflowing the fringed crests of the chestnut groves to invade the day and free the stars from the solar yoke. Under the artificial light of overly violent lights, children play laughing, large numbers of men and women sit at tables and discussions go on, hardly disturbed by the twilight agony. A few heads, however, get up regularly to notice the darkening of the sky and here we see Mars, the incisive star, playing hide and seek with the branches of a chestnut tree stripped of its leaves by the summer drought.
Later, after a few hours of discussions and many shared meals, tired by the hubbub of voices exasperated by music too loud, I leave the table and move away towards the night. I walk blindly in the darkness, trying to remember the configuration of the place, groping with my toes in search of a staircase when I arrive, looking sideways to better perceive the tiny difference in brightness between the path and the thickets that border it. I finally get out of the canopy and what I sensed, by some stellar garlands caught behind trunks, is brutally imposed. What a shock! The celestial vault appears in all its glory, as beautiful as in the depths of a desert, as if, by some magic, I found myself isolated in the heart of the Sahara. Thousands of stars flash in a black velvet sky. What a profusion, what a tintinnabulant symphony of light on the banks of the Milky River!
For so many months, I had lived under the greyish canopy hemmed with orange of a peri-urban sky, contenting myself with the furtive pallor of a thin celestial river, of a wadi with capricious frolics; for so many months, in fact, doubting me but refusing to state this feeling of fear of aggravating it, I was in need of stars. Then, this sudden plunge into the immensity constellated, this sudden confrontation with the absence which makes the common of my nights, suffocates me, amazes me. There is no village here for miles around and the darkness of the celestial conch can express itself, increasing the dazzling presence of the stellar legions. I am subjugated by this rain of silver shavings that gush forth from usually arid and desolate lands. Around Deneb du Cygne, the great galactic artery widens and splits through its middle before diving behind the chestnut trees. The Great Bear’s wagon is parked near the northern horizon; it is so loaded with stars that it struggles to reach the celestial coast.
Moon phases in July
The Moon is in the last quarter on the 6th in Whale, new on the 13th in Gemini, in the first quarter on the 19th in Virgo and full on the 27th in Capricorn.
The sky in July
The dark night is late coming in July and the beginning of celestial observations is postponed around midnight. At this point, if the dazzling Moon is absent, it is possible to discover the Milky Way in sites far from urban lights. It dominates the east side of the night bowl, with the constellation of Perseus flush with the north-north-east horizon, that of Scorpio to the south-south-west and the Summer Triangle suspended at its zenith by its star Vega. Note that the spring figures are still present at the beginning of the night, with the large diamond diamond pattern, which assembles the stars Cor Caroli, Arcturus, Spica and Denebola, lying on the western horizon.
Our galaxy has the approximate shape of a wafer rotating on itself and its axis of rotation points towards the Chevelure de Bérénice, in the middle of the Diamond. With a little imagination, you can “see” the slow gyration of the Milky Way materializing in the sky. The great square of Pegasus rises earlier and earlier above the eastern horizon and it carries the arch of Andromeda which takes you to Perseus if you extend it. In summer, in the northern hemisphere, the ecliptic is folded down towards the southern horizon and the zodiacal constellations, whose names are coloured orange on the maps, are confined in the most turbulent and polluted band of the night sky. Saturn, always installed in full Milky Way at less than 4° of the nebula of the Lagoon (Sagittaire), is well framed by the Martian and Jovian lighthouses.
Maps of the sky visible in July 2018 towards the end of dusk and at the dawn at the latitude of metropolitan France. Click on the maps to view them large and print them for your personal use. The position of the planets is good for the middle of the month. These maps can be used in Europe and throughout the world within a band extending from 38° to 52° north latitude. If you are at more than 45° north, the North Star will be higher in your sky and, in the evening, the constellation of Hercules will be all the closer to the southern horizon. If you are less than 45° north, the North Star will be closer to the North horizon and Hercules will be further away from the South horizon. Careful, these cards aren’t upside down! They simply represent the stars that are above our heads. If you lay with your head to the north and your feet to the south, the east would be to your left and the west to your right. Use these cards by printing and rotating them so that the name of the direction in which you are observing is written upright. The constellations and stars you will find in the part of the sky facing you are all those whose names are legible without tilting your head too much. The names of the constellations and their main stars are indicated, as well as the plot of the most important constellations; this plot is sometimes incomplete when the figure is partly hidden under the horizon. The densest part of the Milky Way is drawn, but you will distinguish this irregular and ghostly band only in a sky sufficiently protected from light pollution. In the city or peri-urban environment, only the brightest stars will succeed in imposing themselves.