This corner of paradise is widely renowned for its beautiful sea, coral beaches and breathtaking sunsets, an endless source of wonder. But we should not forget that every sunset raises the curtain on a fantastic sky, free of light pollution and full of wonders that cannot be seen from our latitudes.
In these pages we present some astronomical observations you can make during your stay in the Maldives. Contrary to popular belief, you can do astronomy even in broad daylight!
These pages come from the author’s decades of experience as a popularizer of astronomy, in collaboration with magazines, websites, publishers and resorts worldwide.
Contact:
paolo.sirtoli@gmail.com
In daytime
The motion of the Sun
Near the equator, the Sun rises and sets… almost vertically.
As shown in the figure below, at mid-northern latitudes, such as in northern Italy, the Sun’s path is inclined at about 45 degrees to the horizon. Near the equator, by contrast, it is perpendicular to the horizon.
This has a remarkable consequence: twilight lasts little more than twenty minutes. It is amazing to be chatting in broad daylight and find yourself in pitch darkness shortly afterward…
The following figures show the hours of daylight (yellow), darkness (gray), dusk (pink) and dawn (blue) for Milan and Malé. The jump in Milan’s graph is due to daylight saving time. In the Maldives, by contrast, the lines are continuous because the country does not observe daylight saving time.
As you can see from the thickness of the blue and pink bands, twilight in the Maldives (about 20 minutes) is significantly shorter than in Europe (about 30 minutes).
You will also notice at once that sunrise and sunset times in the Maldives hardly change during the year. To find out the rising and setting times of the Sun and Moon, see this link.
Please note that most Maldivian resorts set their clocks one hour ahead of local time, to make better use of daylight.
Another consequence of the Sun’s unusual path is that it climbs high in the sky, almost to the zenith, the point directly overhead. So be very careful with its radiation and use a high-SPF sunscreen. An SPF of 30 may seem absurd: why go all the way to the Maldives only to wear the equivalent of a T-shirt? Yet you will tan beautifully even so, and without getting sunburned.
The Sun must only be observed through special filters that block almost all of its light.
If you are lucky, you will see black spots on the solar disk: sunspots. The biggest ones can even be seen with the naked eye, but only briefly at sunset, when the Sun is very low, deep orange-red and dim enough to look at comfortably without squinting. Sunspots are most common around the peaks of solar activity, which follows an eleven-year cycle. The last maximum occurred around 2024–2025, so the next few years will still offer good chances.
NEVER look at the Sun through binoculars or a telescope without a proper solar filter!
Tides
As everyone knows, tides are periodic changes in sea level.
Every day there are two high tides and two low tides, about 12½ hours apart, so each day the tides come about 50 minutes later than the day before.
The difference between high and low tide also varies over a period of about two weeks (spring and neap tides). If the tidal range is at its maximum one day, a week later it will be at its minimum, and a week after that back at its maximum, and so on.
About two-thirds of the tidal effect is due to the Moon and one-third to the Sun. Tides arise because gravity weakens with distance: its pull decreases with the square of the distance.
If we stand on a scale, it records our weight, the force with which the Earth pulls us toward its center. At twice the distance from the Earth’s center (we would have to climb 6,380 km!), we would weigh only a quarter of our normal weight. At three times the distance, we would weigh one-ninth, and so on.
To understand tides, consider a person standing on the Earth’s surface. As we have just seen, their feet are pulled by the Earth with a certain force. Their head, slightly farther from the Earth’s center, feels a slightly weaker pull. The result is a very small force that tends to “stretch” the person lengthwise, just like a… torture rack.
Our planet, immersed in the Moon’s gravitational field, undergoes the same kind of stretching. The solid Earth deforms only slightly, by about 30 cm, while the oceans deform much more, because water is free to flow and gathers into two tidal bulges, called the sublunar and antilunar bulges.
The changing tidal range is explained by the combined influence of the Sun and Moon.
When the two bodies are aligned (at new or full Moon), both stretch the Earth in the same direction, so the tidal range is at its maximum.
When the Sun and Moon are at right angles (first or last quarter), they stretch the Earth in perpendicular directions, the Moon’s effect being the larger. At those times the difference between high and low tide is at its minimum.
There is another effect to consider: since the Earth rotates on its axis in 24 hours, every point passes through two high and two low tides, but also through four tidal currents.
These currents must be taken into account not only for navigation but also for scuba diving. They are weakest around high and low tide (slack water), the best times for diving.
If we compare theory with the actual pattern of tides, we find significant differences.
The truth is that the extremely complicated shape of coastlines and seabeds makes tide prediction very difficult. The only reliable way to predict the tides is to use local tide tables, available from dive centers or online.
One more thing. Corals, which built the Maldives, are silent witnesses of our planet’s past. Their growth, driven by the alternation of day and night and of the seasons, is recorded in their limestone.
In a section of coral we can read the alternation of day and night as thin lines, and the alternation of the seasons as thicker ones. As you would expect, within one year (the distance between two thick bands) we can count 365 thin lines.
But if we study a fossil coral about 400 million years old, we notice something very strange: between two thick bands we can count about 400 thin lines. What does this mean?
It means that a year contained more days, so each day lasted only about 22 hours!
This is because the Earth’s rotation beneath the tidal bulges dissipates energy, so the Earth gradually slows down.
However, physics teaches us that the Earth–Moon system cannot simply lose its spin (physicists call it angular momentum) like a clock running down. Angular momentum is conserved, because the Earth–Moon system is isolated.
So the angular momentum lost by the Earth is gained by the Moon, which therefore moves into an ever wider orbit. It follows that the Moon was once closer to the Earth. Today it is moving away at about 3.8 cm (1.5 inches) per year.
The great writer Italo Calvino wrote a series of short stories called Cosmicomics. The first one, The Distance of the Moon, describes a time when the Moon was so close to the Earth that you could climb up to it on a ladder 😉
I know for sure! – Exclaimed the old Qfwfq – you cannot remember but I do. We had always her, the Moon, huge, when it was full – nights clear as by day, but on a light colored like butter – it seemed as if she were to crush us; when it was New Moon she rolled through the sky like a black umbrella led by the wind, and in waxing Moon she came forward with horns so low that it seemed just about to pierce the crest of a hill and get anchored. But the whole mechanism of the phases was unlike nowadays: because the distances from the Sun were different, and the orbits, and the inclination can not remember what. Not to speak about eclipses! being the Earth and the Moon so close, there were eclipses all the times: imagine if these two beasts could not find a way to cast shadow over each other constantly.[Italo Calvino, Le cosmicomiche, Mondadori]
The green flash
Near the horizon, the Sun is a placid reddish disk, squashed by the atmosphere into a sort of oval. When the sky is very clear, you may be lucky enough to see a beautiful phenomenon: the green flash. The last sliver of the Sun turns a deep, unforgettable green.
A Scottish legend says that those who see the green flash will never be unlucky in love!
The cause of this phenomenon is the Earth’s atmosphere, which not only distorts the shape of the Sun but also splits its light into different colors, rather like a rainbow.
When we see the Sun touching the horizon, we are looking at an effect of atmospheric refraction: the Sun is in fact already below the horizon. Near the horizon our line of sight passes through much more air, which lifts the Sun’s image by about half a degree, roughly its own diameter.
Besides bending the image, the atmosphere also disperses the light, so we get several images of the Sun, each a different color and almost perfectly superimposed.
The red image is at the bottom, the yellow one just above it, and the green one highest. If the air is exceptionally clean, as sometimes happens in the Nordic countries, we may even see the blue one.
Be on the lookout for the green flash when the setting Sun is not very red. For the green flash to be visible, the Sun must stay as white as possible right down to the horizon, without being dimmed and reddened by haze. If we are lucky, we will see the last sliver of the Sun flash bright green for about a second.
The International Space Station (ISS)
In the hour after sunset or before dawn, you may see a very bright light slowly moving across the constellations.
It is not a plane: it does not blink, and through binoculars it remains a point of light. Sometimes it grows redder and fainter until it disappears, as if swallowed by a shadow.
What you have just seen is a pass of the International Space Station, or ISS.
Who would have thought you could see it with the naked eye?
It is a very large structure, about 110 meters across, usually home to a crew of seven. Orbiting at about 400 km, the station circles the Earth in about an hour and a half: every day, the astronauts aboard see sixteen sunrises and sixteen sunsets!
Skilled, well-equipped observers on Earth can take extraordinary photos of the ISS, such as the one on the left. To find out in advance when the ISS and other satellites will pass overhead, go to https://www.heavens-above.com, enter your location and time zone (remember the extra hour that most resorts add to Malé time!) and check the results.
The “mag” column is important: it tells us how bright the space station will be. The scale is reversed: the lower the number, the brighter the pass. In this example, the pass of 7 March 2007 was the one to watch!
That evening, according to the table, we had to be ready at 18:51, looking north-west (NW). The station then climbed to 72 degrees above the west-southwest (WSW) horizon.
Clicking on the date brings up a handy sky chart: hold it above your head, oriented to the cardinal points.
Sometimes the ISS track in the sky is interrupted: that is the moment the ISS enters the Earth’s shadow. We then see the space station grow redder and dimmer.
At that very moment, the astronauts aboard the ISS are admiring a beautiful sunset from space.
Night time
The Sun sets the western horizon on fire and bids us farewell with a wonderful show. Almost unnoticed, the first stars light up, promising a great night.
Minute after minute, the timid lights take courage and the sky fills with stars. Some are dazzling, like Sirius or Canopus; others are barely bright enough to trace the path of the Milky Way, our galaxy, across the sky. The perfect silence makes these moments unforgettable.
The motion of the sky
Imagine going to the North Pole: the North Star would be right above our heads, and all the stars would circle around it, parallel to the horizon.
To make a useful comparison, it is as if the sky were an umbrella that we hold upright and slowly turn.
At our latitudes (about 45°) the umbrella must be tilted by the same angle, so the North Star is only 45 degrees above the horizon, and all the stars rise and set at an angle of about 45 degrees.
In the Maldives, the umbrella has to be tipped almost completely onto its side.
To the north, the North Star is almost swallowed by the Indian Ocean. All the stars rise and set almost at right angles to the horizon. A stargazer used to our latitudes will feel as if they were looking at the sky “sideways”.
The Moon
Like the Sun and the stars, in the Maldives the Moon also rises and sets vertically.
This produces a curious effect: its “horns” point upward or downward. In short, we see the Moon… lying on its side.
The photograph on the right shows a Maldivian Moon with its horns pointing almost straight up.
Unfortunately, the Moon and the wonders of the night sky do not go well together. Moonlight interferes with observing, which is best done when the Moon is waning or near New Moon.
New Moon
The Moon lies in the same direction as the Sun and is therefore invisible. This is a good time for stargazing all night long.
First Quarter
Half of the Moon is lit, and it sets around midnight. This is ideal for public stargazing sessions: in the first part of the night we can observe the Moon, and an hour after it sets, the deep sky.
Full Moon
Its brilliant light washes out the sky. It rises as the Sun sets and stays up all night. Better saved for night diving.
Last Quarter
The Moon rises at midnight, so we can make the most of the first part of the night for deep-sky observing.
To see the Moon’s phases for the current month, see this link. Even with the naked eye, the Moon shows rounded dark areas that in past centuries were called seas (maria). Today we know that there is no liquid water on the Moon: sadly, our satellite is an arid desert of dust and rock.
Of the countless bodies that have struck the Moon, some were so massive that they cracked the lunar crust, letting magma well up. This lava filled the crater floors, leveling them like poured concrete. That is how the seas were born.
Usually, all that remains of an impact is a crater, large or small, sometimes surrounded by rays of debris. Even through a modest telescope, the craters are simply extraordinary.
With a telescope, look along the terminator, the line separating the dark and the sunlit halves of the Moon. There, the sunlight strikes at a grazing angle, bringing out the relief of the lunar mountains.
With enough magnification, the view will be as exciting as a trip into orbit around the Moon!
Finally, a lovely effect can be seen in the days around New Moon, when only a thin crescent is visible. In the Maldives, in fact, the air is so clear that the effect can be seen for several days.
The rest of the lunar disk is not dark, but faintly lit. The first impression is that the Moon has become… almost transparent. This phenomenon is called Earthshine, and it was first explained by Leonardo da Vinci.
Around New Moon, a fully illuminated Earth dominates the lunar sky. Imagine a blue-white disk nearly four times wider than the full Moon. All that light illuminates the desolate lunar plains, and this “Earthlight”, reflected back to us by the Moon, is what we call Earthshine.
The planets
The ancient Greeks called them wanderers (planētai): lights that look like stars but do not stay fixed among the constellations. Five planets are visible to the naked eye; the other two were discovered with the telescope in modern times.
A planet is easy to recognize: it usually shines with a steady light, whereas stars twinkle.
Not all planets are visible at any given time: some may be close to the Sun and lost in its glare. To find out which planets are visible on a given date and time, consult a star chart, such as the free monthly one at https://www.skymaps.com.
Some observational notes:
 | Mercury It spends most of its time hidden in the glare of the Sun, but when it moves away from the Sun it is quite bright in the pre-dawn or post-sunset sky. |
 | Venus A wonderful morning or evening star. A small telescope will show its crescent, just like the Moon. Before dawn, in the pure blue of the eastern sky, it is a truly mesmerizing sight. It brings to mind the tercets of the first canto of the Purgatorio, where Dante says: Soft coloring of oriental sapphire, Collecting in the calm face of the sky, Clear right up to the edge of the horizon, Brought back delight again into my eyes As soon as I stepped out from the dead air Which overburdened both my sight and breast. The beautiful, love-provoking planet Was making the whole east break into smiles, Veiling the Fishes that follow in her train. |
 | Mars It stands out for its distinctly orange-red color, and when you see it late at night it is very bright. A good telescope will show some surface detail: the white polar caps and some dark regions. |
 | Jupiter A very bright “star”: with binoculars the four main satellites discovered by Galileo are clearly visible, lined up along its equatorial plane. Through a telescope its atmosphere shows brown and white bands and the famous Great Red Spot. |
 | Saturn A breathtaking sight: a planet surrounded by a magnificent ring system. If the air is steady, you can catch a glimpse of the Cassini division as a dark gap in the rings. |
 | Uranus and Neptune The two farthest planets of the solar system are practically never visible to the naked eye. Even with a large telescope, they show no more than a small blue-green disk. |
Constellations
The Maldivian sky is very democratic: it makes everyone equal. Beginners and astronomers alike are left open-mouthed at first, unable to recognize a single constellation.
There are so many stars, and so bright (for those of us used to gray-orange city skies), that every familiar landmark vanishes. It brings to mind that awe-inspiring line from 2001: A Space Odyssey, when astronaut Bowman stands before the monolith, just before plunging into his interstellar journey…
David Bowman barely had time to utter a sentence that stuttering men waiting at mission control , millions of miles away fifty eighty minutes in the future, must never forget: ” The thing’s hollow … it goes on forever … and, oh my God, it’s full of stars!
[Arthur C. Clarke, 2001: A Space Odyssey]
At our latitudes, some constellations are called circumpolar because they never set: they are our main reference point in the sky, the place to start when looking for all the others.
In the Maldives there is no such thing: all the stars rise and set, so you will need a star map.
The Maldivian sky in January-February-March
The Maldivian sky in July-August-September