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Life beyond the Arctic Circle. Polar day In which city can you see the sun at night?

Sun moves through the constellation Aquarius until March 12, and then moves into the constellation Pisces. The declination of the central luminary gradually increases, reaching the celestial equator on March 20 (spring equinox), and the length of the day quickly increases over the month. Observations of spots and other formations on the surface of the daylight can be carried out through a telescope or binoculars and even with the naked eye (if the spots are large enough).

It must be remembered that a visual study of the Sun through a telescope or other optical instruments must be carried out (!!) using a solar filter.

Moon will begin to move across the March sky almost at full phase in the constellation Leo. The next day, the night star will take on the full moon phase and move into the constellation Virgo at a phase of 0.99-. Making its further journey across the March sky, the shrinking oval of the Moon will cross the constellation Virgo in three days, passing north of the star Spica on March 5. Having passed at a phase of 0.82- into the constellation Libra on March 6, the Moon the next day will pass north of Jupiter (near alpha Libra) at a phase of 0.7-. On March 8, the lunar oval, with a phase of less than 0.65, will visit the constellation Scorpio, and then enter the domain of the constellation Ophiuchus. Here the Moon will enter its last quarter phase on March 9, appearing low over the southeastern horizon in the predawn hours. On March 10, the large lunar crescent at a phase of 0.4- will move into the constellation Sagittarius, where it will pass north of Saturn (Ф = 0.35-) on March 11 (near the maximum declination south of the celestial equator and the apogee of its orbit). At the end of the day on March 12, the crescent Moon (Ф = 0.2-) will leave the constellation Sagittarius, moving to the constellation Capricorn. Here the Moon will pass the descending node of its orbit on March 14. On March 15, the lunar crescent will reduce its phase to 0.05 and cross the border of the constellation Aquarius, where it will take on the phase of the new moon on March 17 (near the border with the constellation Pisces). Having moved into the constellation Pisces, the new moon (Ф = 0.02+) will appear in the evening sky near Venus on March 18. The next day, the growing month will pass south of Uranus at a phase of 0.05+. Continuing to increase its phase and gaining height above the horizon, the Moon will visit the constellation Cetus on March 20 and on the same day, at a phase of 0.13+, will move into the constellation Aries. The Moon will not stay in the constellation Aries for long and on March 21 it will move into the constellation Taurus at a phase close to 0.2+. Here, on March 22, a growing crescent (Ф = 0.3+) will occult the stars of the Hyades and Aldebaran clusters when visible in northern latitudes. On March 24, almost half of the Moon will visit the constellation Orion and enter the first quarter phase near the border with the constellation Gemini. Here the night star will pass the point of maximum declination north of the celestial equator, being observed most of the night. The lunar oval will enter the constellation Cancer on March 26, having passed the perigee of its orbit near the Nursery star cluster - M44. On March 27, the bright Moon will move into the domain of the constellation Leo at a phase of 0.83+ and will approach Regulus, which will cover it on March 28 already at a phase of 0.9+ and visibility in northern latitudes (near the ascending node of its orbit). The bright lunar disk will move into the constellation Virgo on March 30, and the next day it will end its path here across the March sky in the full moon phase near Spica.

It moves in the same direction as the Sun through the constellation Aquarius until March 2, then moving into the constellation Pisces and remaining there until the end of the month. On March 22, Mercury will change from direct to retrograde. The planet spends the whole month in the evening sky near Venus. Gradually moving away from the central luminary, Mercury will reach evening elongation on March 15 (the best in 2018). The apparent diameter of the fast planet gradually increases from 5 to 10 arcseconds, and the phase decreases from 0.9 to 0.0. This means that when observed through a telescope, Mercury will have the appearance of an oval at the beginning of the month, the appearance of a half-disk in the middle, and then the appearance of a waning crescent until the end of the month. The planet's brightness gradually decreases from -1.5m at the beginning of the month to +4m at the end of the described period. In May 2016, Mercury passed across the disk of the Sun, and the next transit will take place on November 11, 2019.



It moves in the same direction with the Sun through the constellation Aquarius, on March 3 moving to the constellation Pisces, on March 12-14 having visited the constellation Cetus, on March 14 it will again move to the constellation Pisces until March 30, when it crosses the border of the constellation Aries. The evening star gradually increases its angular distance to the east from the Sun (up to 20 degrees) by the end of the month), shining more and more brightly against the background of the evening dawn (near Mercury). A small white disk without details is observed through the telescope. The apparent diameter of Venus is more than 10”, and the phase is close to 1.0 with a magnitude of about -4m.



It moves in the same direction as the Sun through the constellation Ophiuchus, moving into the constellation Sagittarius on March 11. The planet is observed at night and morning hours above the southeastern and southern horizon. The planet’s brightness increases from +0.8m to +0.3m per month, and its apparent diameter increases from 6.6” to 8.4”. Mars is gradually approaching the Earth, and the opportunity to see the planet near opposition will appear in July. Details on the surface of the planet (large) can be visually observed using an instrument with a lens diameter of 60 mm, and, in addition, photographically with subsequent processing on a computer.



It moves in the same direction as the Sun in the constellation Libra near the alpha star of this constellation. The gas giant is visible in the morning and night sky for more than six hours. Angular diameter itself big planet The solar system increases per month from 39” to 42.5” with a brightness brighter than -2m. The planet's disk is visible even through binoculars, and through a small telescope, stripes and other details are visible on the surface. Four large satellites are already visible with binoculars, and with a telescope in good visibility conditions you can observe the shadows of the satellites on the planet’s disk.



Moves in the same direction as the Sun in the constellation Sagittarius. The ringed planet can be observed in the morning hours above the southeastern horizon. The planet's brightness is +0.5m with an apparent diameter exceeding 16". With a small telescope you can observe the ring and the Titan satellite, as well as other brighter satellites. The apparent dimensions of the planet's ring are on average 40x15” with an inclination of 26 degrees to the observer.



(5.9m, 3.4”) moves in the same direction as the Sun in the constellation Pisces near the star Omicron Psc with a magnitude of 4.2m. The planet is visible in the evening sky. Uranus, rotating “on its side,” is easily detected with the help of binoculars and search maps, and a telescope with a diameter of 80 mm or more with a magnification of more than 80 times and a transparent sky will help you to see the disk of Uranus. The planet can be seen with the naked eye during periods of new moons in the dark. clear sky, but such an opportunity will present itself only in the fall of this year. The satellites of Uranus have a brightness less than 13m.



(7.9m, 2.3”) moves in the same direction as the Sun in the constellation Aquarius near the star lambda Aqr (3.7m). The planet has ended evening visibility and will be in conjunction with the Sun on March 4th. Neptune will appear in the morning sky at the end of the month. To search for the most distant planet in the solar system, you will need binoculars and star maps in the Astronomical Calendar for 2018, and the disk is visible in a telescope of 100 mm in diameter with a magnification of more than 100 times (with a clear sky). Neptune can be captured photographically with the simplest camera with a shutter speed of 10 seconds or more. Neptune's moons have a brightness of less than 13m.

From comets, visible in March from the territory of our country, at least three comets will have a calculated brightness of about 11m and brighter: PANSTARRS (C/2016 M1), PANSTARRS (C/2016 R2) and Heinze (C/2017 T1). The first, with a brightness of about 11m, moves through the constellation Aquila. The second moves through the constellation Taurus and Perseus at a magnitude weaker than 11m. The magnitude of the third comet is also about 11m, and it moves through the constellation Pegasus.

Among asteroids the brightest in March will be Ceres (7.3m) - in the constellation Cancer and Vesta (7.1m) - in the constellation Ophiuchus and Sagittarius.

Of the relatively bright long-period variable stars maximum brightness this month according to AAVSO data was reached: Y Persei 8.4m - March 1, R Persei 8.7m - March 1, RR Sagittarius 6.8m - March 4, W Andromeda 7.4m - March 5, ST Sagittarius 9, 0m - March 8, S Canis Minor 7.5m - March 9, V Cancer 7.9m - March 11, X Delphinus 9.0m - March 11, RT Centauri 9.0m - March 12, S Microscope 9.0m - March 15 , V Pegasus 8.7m - March 17, W Auriga 9.2m - March 18, R Taurus 8.6m - March 19, X Unicorn 7.4m - March 19, R Leo 5.8m - March 19, W Hercules 8, 3m - March 19, X Hydra 8.4m - March 20, U Cassiopeia 8.4m - March 21, SS Ophiuchus 8.7m - March 21, S Compass 9.0m - March 26, X Ophiuchi 6.8m - March 26, Y Dragon 9.2m - March 28, S Gemini 9.0m - March 29.

Among the main meteor showers On March 14, the gamma-Normids (ZHR= 6) from the constellation Angugol will be at maximum activity. This is a southerly flow with a radiant declination of -50 degrees.

It was discovered in ancient times, when there were no telescopes. The nature of their movements across the sky is different from movement. Based on this, people separated from millions of stars.
There are inner and outer planets. Mercury and Venus are closer to the Sun than the Earth. Their location in the celestial firmament is always close to the horizon. Accordingly, these two planets are the inner planets. Also, Mercury and Venus seem to follow the sun. Nevertheless, they are visible to the naked eye at the moments of maximum elongation, i.e. during maximum angularity from the Sun. These planets can be seen at dusk, shortly after sunset, or in the predawn hours. Venus is much larger than Mercury, much brighter, and easier to spot. When Venus appears in the sky, not a single star can compare with it in brightness. Venus shines with white light. If you look closely at it, for example, using binoculars or a telescope, you will notice that it has different phases, like the Moon. Venus can be observed in the form of a crescent, waning or increasing. In early 2011, Venus was visible for about three hours before dawn. It will be possible to observe it with the naked eye again from the end of October. It will be visible in the evening, in the southwest in the constellation Libra. Towards the end of the year its brightness and duration of visibility will increase. Mercury is mostly visible during twilight and is quite difficult to detect. For this, the ancients called him the god of twilight. In 2011 it will be visible from the end of August for about a month. The planet will first be visible in the morning hours in the constellation Cancer, and then move to the constellation Leo.

The outer planets are Mars, Jupiter and Saturn, respectively. They are best observed in moments of confrontation, i.e. when the Earth is on the same line between the planet and the Sun. They can remain in the sky all night. During the maximum brightness of Mars (-2.91m), this planet is second only to Venus (-4m) and Jupiter (−2.94m). In the evening and morning, Mars is visible as a red-orange “star”, and in the middle of the night the light changes to yellow. In 2011, Mars will appear in the sky in the summer and disappear again at the end of November. In August, the planet can be seen in the constellation Gemini, and by September it will move to the constellation Cancer. Jupiter is often visible in the sky as one of the brightest stars. Despite this, it is interesting to observe it with binoculars or a telescope. In this case, the disk surrounding the planet and the four largest satellites become visible. The planet will appear in June 2011 in the eastern sky. Jupiter will approach the Sun, gradually losing brightness. Closer to autumn, its brightness will begin to increase again. Jupiter will enter opposition at the end of October. Accordingly, the autumn months and December are the most best time for observing the planet.
From mid-April to early June, Saturn is the only planet that can be observed with the naked eye. The next favorable period for observing Saturn will be November. This planet is slowly moving across the sky and will be in the constellation Virgo all year.

Helpful advice

It is better to observe the night sky outside the city limits.

Sources:

  • what planets are visible today

People have been interested in celestial bodies thousands of years ago. Thanks to research, a huge amount of information has been accumulated about stars, planets, galaxies and other space objects. Of course, it is advisable to have a telescope to observe the sky. But, for example, you can distinguish a planet from a star even with the naked eye by characteristic features.

Instructions

Please note that only the planets of our solar system can be seen with the naked eye or through a telescope. Planets shine with light reflected from stars, which means they shine less brightly. And stars are self-luminous celestial bodies and are visible at great distances.

Watch the sky over several evenings and you will notice objects that change their position relative to the constellations. These are the planets. Mark your movements on a special map or draw your own in a notebook.

Every day we observe various atmospheric phenomena. Most often we do not think about their features and nature. But it’s worth taking a closer look around - and we will notice that many of these phenomena are much more interesting than they seem at first glance. One clear example is twilight.

What is twilight? This definition refers to two time periods:

  1. the period of time between apparent sunset and nightfall;
  2. the period between night and visible sunrise.

So, we have answered the question of what twilight is. But it turns out that they are divided into three types:

  • civil;
  • navigation;
  • astronomical.

In this article we will talk in detail about the features of each type of twilight.

Civil twilight

From the image above you can learn about Blue Hour and Golden Hour.

Civil twilight begins when the Sun sets and ends when its center has dropped 6 degrees below the horizon. This type of twilight is the lightest. For this reason, small stars cannot be distinguished in the sky. But under favorable atmospheric conditions, the brightest celestial bodies can be observed. So, in cloudless weather during civil twilight, you can see Venus in the sky without using optical instruments.

During this period of time, you can see all ground objects almost as well as in the daytime. Therefore, in the morning civil twilight you can begin, and in the evening, complete work carried out in the open air. By the way, that’s why they are called civilian - at this time you can see well without additional lighting.

In some latitudes, civil twilight can last throughout the night. In other words, evening twilight gradually turns into morning twilight instead of night. This phenomenon is usually called white nights. On the territory of Russia they can be observed in St. Petersburg, Perm, Yakutsk, Vorkuta and a number of other cities.

Navigational twilight

After the end of evening civil twilight, the time of navigational twilight comes. They can also be observed before the onset of morning civil twilight.

During this period, the center of the Sun is located 6-12 degrees below the horizon. During navigational twilight, vague outlines of ground objects can be distinguished. However, without artificial lighting it is not possible to see their details. During this period, it is impossible to distinguish the colors of objects. For these reasons, field work without the use of lighting devices is not carried out in such conditions.

But during this period of time you can see all the navigation stars. At the same time, the horizon line is visible. This allows navigators to navigate in space using a sextant, measuring the angles between the horizon and the stars - therefore, twilight is “navigational.”

The military often launches attacks during navigational twilight. This is due to the fact that during this period it is most difficult for the enemy to detect them.

Astronomical twilight

Astronomical twilight is the period of time when the center of the Sun is 12-18 degrees below the horizon. With their onset, astronomers can begin observing most celestial objects. During this period, not only large planets and stars are clearly visible, but also small luminaries. However, objects with a particularly weak and diffuse glow can only be seen on astronomical nights.

However, the difference between night and astronomical twilight is clear only to those who specialize in the study of celestial bodies. For an ordinary observer, the transition from astronomical twilight to night is completely invisible. In other words, they are perceived as part of the night.

We hope that in this article you found a detailed answer to the question of what twilight is. It remains only to note that the duration of twilight in general and each period in particular varies greatly, depending on the latitude at which they are observed.

Residents of tropical and temperate latitudes rarely have the opportunity to sit at midnight on the shore of a lake and calmly read a book in almost daylight. To do this, they need to go far, far to the north and be at a distance of about 2.5 thousand km from the extreme pole of the Earth in order to see the polar day.

After all, only there is it possible to look at the absolute reluctance of the daylight to go beyond the horizon at night, thanks to which the sky acquires a special, one might even say, mystical charm. And life continues to be in full swing even at night.

This phenomenon is most common in the Arctic. A polar day in the Arctic lasts from 64 to 186 days. Its duration increases north of the Arctic Circle.

Polar day is a period of time when the disk of the Sun is completely in the sky:

  • in the Arctic Circle - at least two days;
  • at the poles - about six months (in the south of the planet the duration of the most have a long day lasts from September 21 to March 23, in the north - from March 18 to September 26).

The length of the polar day primarily depends on which parallel a particular area is located on. In the Arctic Circle region, the daylight remains in the sky only for several days - during the solstice. At latitude 68° this natural phenomenon lasts about forty days, and at the extreme points globe, at the poles this period is about 189 days.

This happens due to the fact that in summer our planet faces the daylight of one of the poles. Despite the fact that the Earth rotates around its axis, the pole does not go into the shadow at all (however, the Sun itself does not rise very high above the horizon) - because of this, here for a certain period of time you can observe such a natural phenomenon as constant a day that differs from normal in that it is not part of the day.

This phenomenon can be observed annually from the North or South Poles to latitudes located slightly south (north) of the Arctic Circle.

Namely, near the parallel, which is located in the region of 66°33′, minus the radius of the solar disk (15-16′) and minus atmospheric refraction - this is the name given to the refraction of light rays from the Sun or Moon in the atmosphere of our planet, when the images of celestial bodies are in our eyes “ rise" to a higher height than they actually are.

Based only on astronomical calculations, at the latitude of the Arctic Circle on the day of the summer/winter solstice (namely June 22/December 22), the Sun at midnight should go below the horizon at least halfway, and then begin to rise again. Instead, due to refraction, we can observe the full solar disk in the polar circles for several days, at the poles for an entire summer.


Formation of the phenomenon in the Northern Hemisphere

Such a day can be seen even one degree south of the conventional value of the Arctic Circle - approximately in the region of 65°43′ (however, here its duration lasts no more than two days). This parallel is located almost 3 thousand km from the North Pole and passes through:

  • Norway,
  • Sweden,
  • Finland,
  • Canada,
  • Greenland,
  • Iceland,
  • Alaska,
  • Russia - namely: Karelia, Solovetsky Islands, Arkhangelsk region, Krasnoyarsk region, Magadan region, Chukotka,
  • and, of course, the phenomenon occurs in the Arctic.

Despite the fact that residents living near the Arctic Circle cannot be surprised by such a phenomenon as the 24-hour Sun in the sky, there is no polar night here yet. Polar day and polar night begin in more northern latitudes - from 67°24′, namely in the Arctic. The polar night in the Arctic occurs in the winter season.


Southern Hemisphere

As for the Southern Hemisphere, the Arctic Circle here completely passes through Antarctica and lies at 66°33′44″. The duration of the polar day here is also several days (and this phenomenon can be observed one degree north of the Arctic Circle). At the same time, at the South Pole itself, this phenomenon lasts from September 21 to March 21.

What does the longest day look like?

As already mentioned, the closer to the most extreme points Earth, the longer the day. The duration of this amazing phenomenon both in the North and in South Poles lasts more than six months. Under good weather conditions, you can watch the daylight here all day long, since it absolutely does not leave the horizon and moves along it in a circle.

Thanks to refraction on the day of spring and autumn equinox The sun illuminates both poles simultaneously for several days in a row (on one at this time the wonderful day is ending, on the second it is just beginning.

What is the difference between the phenomenon and white nights?

Many people confuse polar days with white nights and do not fully understand how they differ from each other. It is not difficult to distinguish them. White nights can be seen when twilight reigns at night, but the daylight is not visible on the horizon because it has set, and we observe polar days when the Sun shines around the clock (of course, if the weather is good).

Impact on humans

It is not easy for visitors to acclimatize in latitudes where the polar day lasts for several days (and even months). Local residents have long adapted to this phenomenon.

For example, in Russia, at night, in order to be able to rest properly, people wear thick blindfolds over their eyes, and hang dark thick curtains and even blankets on the windows (to darken the apartment at least a little). In almost all apartments, small nails are nailed around the perimeter of the windows, which makes hanging such fabric much easier and faster.

During this period, it is quite difficult for mothers who find it difficult to get their children to sleep, and for people who work shifts and do not have a stable daily routine: having woken up, for example, at four o’clock, they cannot always immediately determine whether it is day or night.

The sun is the source of life for our planet. The heavenly body caresses us with its warmth, illuminates us during the day and gives joy to everything that exists on Earth. Another important function: orientation assistance. Thanks to the sun, we can determine the cardinal directions and choose the right direction.

Sun way

Every morning the gentle sun calls us to awakening and new discoveries in this wonderful world. And in the evening, making its slow move across the sky, it goes beyond the horizon, giving you the opportunity to relax after a busy day of work. Where does this journey begin? Where does the sun set at the end of the journey?

The rise of the main luminary begins in the east. The sun leaves us at the end of the day in the west. After this, it continues its journey, but on the other side of our amazing planet. And in the morning it rises again in the east. This is how the picture described appears to us from Earth. Interestingly, ancient people considered this point of view to be incorrect. In this case, where does the sun actually set, and how does it appear again in the sky?

If you do not delve into the details of the worldview of the inhabitants of antiquity, then we can say that they were right. The fact is that our planet is part of the solar system, where the Sun is motionless and located in the center. The Earth moves around it in its orbit and, in addition to this movement, rotates around its imaginary axis. The planet makes a full revolution in 24 hours, in other words - in a day. That is why it seems to us that the places where the sun sets and where it returns in the morning are unchanged.

View from space

If I had the opportunity to look at solar system far from space (so as to see absolutely all the planets), then the picture would be as follows: all the celestial bodies of this system rotate in the same direction from west to east (counterclockwise). In fact, Venus rotates around its axis in the direction opposite to the rotation of other planets. There are assumptions by astronomers that many years ago a very powerful asteroid hit it and disrupted the direction of rotation with its impact. Uranus, too, under the influence of similar forces, seemed to be overturned. Now, watching it, you see the picture of rotation as if from the side.

North Pole and other parts of the world

If a person could study the movement of the main luminary from the North Pole, he would see the rotation of the Earth counterclockwise, as well as the place where the sun sets and how it rises. Visually, the movement of the celestial body will appear as a move from east to west. In fact, it will move east, and the Earth will rotate around its axis.

Interestingly, in different parts of the world the sun does not rise at the same time. For example, on the East Coast of the United States this occurs another 3 hours before those areas that are on the Western coast. Accordingly, the sunset at different parts light occurs at different times.

Twilight

The immediate period of time before sunrise and before sunset is twilight. This is a particularly beautiful sight. The disk of the celestial body is located very close to the horizon, some of the rays enter the upper atmospheric layers and are reflected on the surface of the Earth. The duration of such a colorful spectacle lasts about 2 hours. But this is only in temperate latitudes. In the polar zones, twilight lasts several hours before sunset. Directly at the poles, this period takes from 2 to 3 weeks! At the same time, at the equator, before sunrise, twilight lasts only 20-25 minutes.

At this time, thanks to the optical effect, we see a stunning picture when the rays of the sun illuminate the surface of the Earth and the sky in multi-colored tones.

Orientation: how to determine the cardinal directions without a compass on the ground?

If you have a wristwatch with hands (not electronic), then in the “horizontal” position you need to turn it clockwise towards the sun. Drawing an imaginary bisector between the number 12 and the direction to the celestial body, we obtain a “north-south” line. It is also interesting that until noon, the south is to the right of the sun.

Understanding how to determine the cardinal directions without a compass, a person will be able to navigate anywhere and go in the right direction. This knowledge is very important, especially for tourists, forestry workers, hunters, sailors and people engaged in other activities.

The method described above can give relatively accurate results in northern latitudes. In temperate climates it works only partly (especially in winter). In the southern regions, the summer sun is high, so errors may occur. In addition, you need to take into account the transition to and from daylight saving time (as this affects the definition of noon).

It is also important to remember where the sun rises and where it sets in mid-latitudes. In these places, the main luminary rises in the summer in the northeast, and sets in the northwest. 3rd - in the southeast and southwest, respectively. Only 2 times a year the sun rises exactly in the east and sets exactly in the west. These are the days of the equinoxes - March 21 and September 23.

Shadow and navigation

There is another way to navigate by shadow. In unfamiliar places, when this need arises, you need to take into account different heavenly bodies. At night it can be the polar star, and during the day it can be the sun.

Understanding which side the sun sets from, you can determine other directions of the world and choose the right direction of travel. For example, in northern latitudes, when the time of summer nights comes, the setting sun is close to the horizon. Therefore, the sky on the north side is lighter than on the south.

It is known that the highest solar position can be determined by the shortest shadow. This corresponds to noon. The direction of such a shadow points to the north. It’s the same with the moon: if it’s full and occupies the highest position above the horizon, it means it’s in the south. This is the time when there is enough light to clearly distinguish shadows. Likewise, during a full moon, the shadow is the shortest. It's midnight. The direction of the shadow will point to the north.