Is it possible to see a satellite at night? Lies in orbit
Nowadays, the topic of satellite images often comes up in conversations far from space. At the same time, the ancient myths of the Cold War, about “reading the license plate number” and “counting the stars on shoulder straps” or even “reading the newspaper,” are being washed from discussion to discussion.
Today we are on specific examples Let's look at what space optics is capable of, and whether everything is visible from above.
To begin with, a small discovery for many: Google Map does not have satellite images with a resolution higher than 50 cm per pixel. Until recently, commercial distribution of more detailed satellite imagery was prohibited in the United States. Therefore, if you find photographs in some city where you can see people walking and other details - this is aerial photography, you can publish it.
This contradiction did not suit private space traders for a long time, and they nevertheless lobbied for a relaxation of the law, and now it is possible to sell images with a resolution of up to 25 cm per pixel. This is the limit of commercial satellite imaging today.
But even such photographs require sophisticated technology. For example, DigitalGlobe’s WorldView-3 satellite: resolution 31 cm, telescope mirror diameter 1.1 m, cost $650 million.
As an example, DigitalGlobe posted pictures of Madrid.
As you can see, you can see a lot of details: passenger cars are easy to distinguish from trucks, even, it seems, people swimming in pools can be seen as dots. But Madrid was not chosen by chance: the closer to the equator, the less cloudy it is. Dubai is also often chosen to demonstrate the capabilities of satellites - there are many colorful objects there, and the desert weather is conducive to observation.
The colossal costs of creating private satellites capable of such high-quality imaging raise a logical question: how do they pay for themselves? There is no secret to this: more than 50% of DigitalGlobe's orders come from the Pentagon. The rest is from Google and individual customers.
But these are still commercial satellites, but what can the military and the CIA do?
Everything is more complicated here, but on the whole it is quite predictable. The legendary and most powerful American spy satellite belongs to the Keyhole-11 series. Little is known for certain about it, even its appearance is not completely clear, although amateur astronomers periodically “intercept” it.
But it is known that the Hubble space telescope was created on a production line from which spy satellites had previously come off, and a couple of years ago the American spy department (National Reconnaissance Office) donated to NASA two telescopes with a diameter of 2.4 meters, which were lying around in a warehouse.
Therefore, it is most likely that KH-11 has a mirror with a diameter of 2.4 meters, like the famous Hubble Space Telescope.
Through a simple comparison with WorldView-3, which has a 1.1 meter mirror, we find that the quality of spy shots should be about 2.3 times better. But there is a difference: WorldView-3 flies at an altitude of 617 km, and the youngest KH-11 (called USA-245) at an altitude of 270 to 970 km.
The Hubble Space Telescope, from an altitude of 700 km, could image the Earth with a resolution of up to 10-15 cm, in ideal conditions, if it were allowed technical capabilities. Accordingly, the KH-11 at the lowest point of its orbit is capable of providing a resolution of up to 5 cm. But, again, this is under ideal conditions, in the absence of clouds, smog, fog and just dust above the subject. In addition, the higher the resolution and the closer the satellite is to the Earth’s surface, the at the same swath of his shooting and less opportunity to look around. Those. It is advisable to use such survey only for previously explored objects, in clear weather, and only at a time determined by the orbit of the device.
That’s why the American military pays the American businessmen to keep their technical means not enough, and it’s easier to buy necessary pictures than to create a bunch of satellites, each costing as much as an aircraft carrier.
And to imagine the quality of the pictures in different resolutions, I prepared a rough diagram based on aerial photography data.
Thus, in ideal conditions, theoretically, just one spy satellite is able to see the license plate on a car in the form of several white pixels. But reading the issue, not to mention the shoulder straps and newspapers, is simply physically impossible.
Is it visible to the naked eye on a clear night? artificial satellites Earth?
Indeed, satellites are visible without any weapons, but everything depends on the illumination of the satellite. As soon as a satellite flies into the shadow of the earth, he immediately turns invisible.
I always loved watching starry sky. Especially when I come to the village to visit my parents. Late in the evening, dad and I will go out and look at the stars, looking for constellations. And of course we see artificial earth satellites without the naked eye. You can immediately see it if you look closely at the sky. All the stars stand still, but the companion star moves.
It is possible, but only in the southern regions. For most satellites, the ISS is no exception, the angle of inclination of the orbital plane to the equatorial plane does not exceed 45 degrees (if you do not take special measures when launching a satellite into orbit, the inclination angle cannot exceed the latitude of the launch site; for the ISS this is the latitude of Baikonur). Even taking into account the fact that from an altitude of 350-400 km you can see far away, even at latitudes of about 50 degrees the satellites barely hover above the horizon.
And only for the satellites of the Iridium system the orbital inclination is 86 degrees (with a tail), so they are visible at any latitudes. If you're lucky...
Artificial satellites of the Earth, despite their small dimensions, are in orbits very close to the surface of our planet.
Yes, they are often clearly visible.
They differ by eye in their noticeable movement relative to the almost static observed stars, brightness and large visual size.
If your vision is good, then the satellites can be seen with the naked eye, if not so - with the armed eye (with glasses). But one way or another, on a clear night, most often outside the city, satellites can sometimes be detected - they are bright points moving across the sky, similar to stars.
The brightest satellites visible from Earth are Iridiums. These are satellites telephone communication with huge antenna panels and solar panels. These panels give reflections - sunbeams at certain points of the globe, and if you hit this point, then a star of insane, dazzling brightness suddenly flares up in the sky, and after a few seconds it gradually fades away. So if you see this, don't think it's a UFO or a cosmic nuclear explosion.
A less bright, but also noticeable man-made object is the ISS. Its brightness reaches the brightness of Jupiter, and its details can be seen with a strong spotting scope or amateur telescope. It is useful for radio amateurs to know the two frequencies at which the ISS can be heard: 145.800 and 143.625.
In addition to these very bright objects, there are many satellites that are easily observed with the naked eye. Sometimes there is not one, but several such satellites in the sky at the same time. In order to find out which satellites will fly by when, you can use the large database on the website http://www.heavens-above.com/.
Remember the movie “Men in Black”, where Agent Kay looked through an orbital camera at his beloved watering flowers in the courtyard? The opportunity to see what our Earth looks like from a satellite in real time attracts people from all over the world. Today we will tell you - and show you! - the best fruits modern technologies on Earth observation.
Attention! If you see dark screen, this means that the cameras are in the shadows. Screensaver or gray screen- no signal.
Usually we only get static satellite maps, frozen in time - details have not been updated for years, and an eternal summer day reigns outside. Isn't it interesting to see how beautiful the Earth is from a satellite online in winter or at night? In addition, the quality of images of some regions of Russia and the CIS leaves much to be desired. But now all this can be solved in one fell swoop - thanks to , Earth online from a satellite in real time is no longer science fiction. Right on this page you can join thousands of people who are now observing the planet.
At an altitude of 400 kilometers above the planet, where the station is permanently located, NASA installed one developed by private companies. The astronauts themselves or at the commands of the Mission Control Center direct the cameras from which data is transmitted. Thanks to manual control, we can see what the Earth looks like from a satellite online from all sides - its atmosphere, mountains, cities and oceans. And the mobility of the station allows you to view half of the globe in an hour.
How does the broadcast happen?
Thanks to the fact that the cameras are located at the International Station, even minor details are visible to us, which are commented on by scientists, astronauts and professional journalists. However, our Earth is visible online from a satellite in real time thanks to the work of a whole complex of people and machines - in addition to the already mentioned astronauts and the Control Center, those involved in the process satellite technologies communication transmissions, solar power batteries and technical specialists involved in data translation and decoding. Accordingly, the broadcast has its own nuances - knowing them will help you see more and better understand what is happening on the screen.
Our observation point, the orbital station, moves at enormous speed - almost 28 thousand kilometers per hour, and circles the Earth in 90-92 minutes. Half of this time, 45 minutes, the station hangs on the night side. And although on approach the solar panels of the cameras can be powered by sunset light, in the depths the electricity disappears - therefore it is not always available from the satellite. At such moments, the broadcast screen turns gray; Just wait a little and you will be watching the sunrise with the astronauts.
In order to find best time for observations, you will need our special card Earth from a satellite - it marks not only the time of passage of the space station, but also its exact position. This way you can find out when to see your city from space heights, or find a station in the sky with binoculars or a telescope!
We have already mentioned that astronauts and ground control can change the aiming of cameras - they provide not only entertainment, but also scientific function. At such moments, planet Earth is not accessible from a satellite in real time - a black or blue screensaver appears on the screen, or already captured moments are repeated. If there are no interruptions in satellite communications, the station is located on the day side of the planet, and the background suddenly changed, which means the cameras are filming areas inaccessible to the public due to international treaties. Secret objects and forbidden territories are closed on static maps, skillfully hidden by photo editors or simply erased. All that remains is to wait for the moment when the situation in the world relaxes, and there will be no secrets from ordinary citizens.
Hidden Features
But don't be upset if the camera isn't working right now! When planet Earth cannot be shown online from satellite, astronauts and NASA find other entertainment for viewers. You will see life inside the International Space Station, astronauts in zero gravity, who talk about their work and what kind of satellite view of the Earth will be shown next. They even allow you to look into the impressively large Mission Control Center. The only negative is that even the speech of Russian cosmonauts is translated into English so that it can be understood by the American employees who manage the Center. Turn off translation to this moment impossible. Also, don’t be surprised by the silence - comments are not always appropriate, but constant soundtrack Not yet.
For those who predict the route of cameras using the capabilities provided by a real-time satellite map of the Earth, we have advice - check the date and time settings on your computer. The server that updates the map uses the given International Station motion formula and the time zone of your IP address to predict the position of the orbital cameras. What does the Earth look like from a satellite? online map judges solely by device time. If your clock is slow or fast relative to the time zone, the station will move east or west accordingly. The use of proxy servers and anonymizers will also affect the results.
Live broadcast of NASA TV channel
You are a participant in a scientific program
Surely you have noticed that the quality of the picture of the planet Earth from space, live broadcast from a satellite, often changes - the image is covered with squares or lags behind audio track. In most cases, it is enough to check the speed of your Internet connection, disable other videos and programs for downloading files, or click on the HD button in the broadcast window. However, even if there are interruptions, it is worth remembering that the planet can only be seen alive thanks to a large-scale scientific experiment.
Yes, yes - the video on this page is transmitted for a reason. Cameras installed on the International Space Station are part of the program High Definition Earth Viewing (from English: view of the Earth from a satellite in high resolution), which is still being improved and developed. The cameras are installed by astronauts in conditions isolated from cold and dust, but they are exposed to harsh radiation from the outside. Scientists are experimenting with the difficulties of seamless data transmission in space, ensuring that a map of the Earth from a satellite good quality existed not only motionless, but also living, dynamic. The results will help improve existing channels and create new ones - even in Mars orbit in the foreseeable future.
So let's stay in touch - new things appear in the world of space every day!
Interesting to a recent post:
when I was watching the eclipse, I also saw a bright object flying high from west to east, quite bright compared to stars. revised the approximate time, magnitude and direction according to the Stellarium program. it turned out that it was the ISS)
I have always been surprised by statements that the ISS and other satellites declared by officials are visible from Earth with the naked eye. Let's try to figure it out.
The ISS orbit is declared at an altitude of 408 km.
Max. The dimensions of the station are stated to be 109 meters (including deployed batteries). This is approximately 4 carriages of a passenger train or 7 trucks (20-ton, Euro-trucks).
And as far as I know, the ISS is the largest orbital object (of our civilization).
Now remember the view from the airplane window during the flight.
Do you remember? Were the trucks or trains below clearly visible?
And this is only 10 km altitude...
To check, consider this thing:
Here are 2 islands on Lake Chapala in Mexico.
I chose them for two reasons:
1. On the surface of the water, the island is better visible than any other artifact on the ground, which is all built up and objects are mixed into mush at a distance (you can, of course, look for solar panel farms in the desert for maximum clarity, but you’re too lazy. If you find it, please let us know)
2. One of the islands is clearly visible from a height; it can be used as a landmark
We pay attention to the small island. Its dimensions are 2.5 times larger than the ISS (~260 by 100 m) and it is clearly visible from a height of 5.44 km, like the large one nearby:
And now we rise to an altitude of 400 km:
Do you see such a small dot there right between the tip of the arrow and the letter P?
This big the island and it is barely visible. The little one disappeared completely.
Watched it on normal Google Earth with a screen resolution of 1920x1080. You can try it yourself.
It is clear that the ISS and its mirror arrays can reflect, but is this light enough to be visible from Earth?
Other satellites, as far as I know, do not at all exceed the size of machines with orbits of at least 200 km, and this is for spy vehicles, which obviously will not be entered into civilian databases.
If such arguments seem insufficient to you, remember that 400 km is the distance from Moscow to Nizhny Novgorod.
And try to see not even a single building, but the entire city from such a distance)
Or just look at the Earth in reverse order, preferably in full screen:
Earth from space in 4k. ISS flights over the continents of the Earth, the latest images. VITA mission. ESA 2018
At the 1:45 mark, Geneva's Lake Leman is visible.
The arrow marks the Geneva Cointrin airport; against the general background of the city, it can also be used as a landmark:
This is what it looks like when full screen with 4K video quality:
The length of the runway is ~4 km, the width including the lawns is ~400 m, but even it is almost invisible from a height of 400 km!
So is it possible to see the ISS from this distance, do you think?
And bonus questions from our quiz:
Who or what is taking all these masterpiece pictures of the ISS from a couple of hundred meters, a quadcopter, a satellite, a kamikaze paparazzi?
Why don't you ever see the stars in them unless it's obviously photoshopped CGI?
ALL videos of the astronauts going into space were filmed from on board, THERE IS NOT A SINGLE VIDEO filmed from the side, only graphics! Can you explain this?
And why not record the eclipses that are so interesting to everyone on the ISS cameras, since NASA and other agencies constantly broadcast them from Earth? ;)
UPD from comments:
This is what the ISS altitude of 400 km looks like compared to the planet.
What lights it up from below, the city lights? because the sun can only do this for a VERY short period
Is it possible from this height to see such a refraction of the surface, as they show us, i.e. almost a quarter of the planet, and sometimes more?
Many people believe that the International Space Station (ISS) flies somewhere very far away, and in order to see it (let alone photograph it) you need special equipment. However, this is not at all true. The ISS flies over our heads several times every day and seeing it is no more difficult than an ordinary passenger plane. You just need to know when and where to look. The brightness of the ISS can compete even with Jupiter and Venus, and its rapid movement across the sky attracts attention even more. In this article I want to tell you how and when you can see the ISS tonight in Moscow, I’ll tell you how to find out the time of passage of the ISS for any other place and date, and also touch on the topic of photo and video shooting of the ISS.
What will be needed for observations?
No telescopes or binoculars will help us; they will even harm us. The fact is that the ISS is moving very quickly, catch and track it optical device It's difficult with high magnification. This gif gives some idea of her speed.
And we will need clear skies (everything is in order tonight):
… And open area With good review to the southwest, south and southeast (for example, a supermarket parking lot, a sports ground, the roof of a building, etc.). The proximity of bright lights will not hurt us, since the ISS is a very bright object. If you are too lazy to go outside, you can get by with a balcony or window facing south.
You also need a clock synchronized with exact time, and a compass (in case you don’t know at least the approximate directions to the cardinal points at the chosen point for observations).
When and where to look?
The ISS completes one orbit in about an hour and a half. This means that if the Earth did not rotate, we would see the ISS flying along the same trajectory every hour and a half. Since the Earth still rotates, the “footprint” from the ISS on the Earth’s surface shifts to the west with each revolution. In addition, the ISS is visible only when it itself is illuminated by the Sun, while it is already dark at the observer’s location (you can manage it, but it’s more difficult). To calculate today's visible passages of the ISS over Moscow, I used the online service heavens-above.com (residents of other cities can easily get the ISS visibility conditions there themselves). The most favorable passage for observations is expected today at approximately 22:47.
The stars on the map won't help us much since they are hard to see in the city. It’s easier to navigate the cardinal directions using a compass. If you don’t have a compass, look for the direction where the evening dawn is burning, it will be northwest.
The ISS will ascend at 22:42:30 , but it’s too early to start looking for it at this time. At the very horizon it is still not bright enough, and trees, buildings and haze may interfere with the view. It is better to wait until it rises at least 10 degrees above the horizon. This will happen in 22:44:38 , the ISS will be somewhere between the west and southwest. You will notice a dim, non-flickering star that is slowly moving to the left and up. This star is the ISS flying somewhere over France at a distance of one and a half thousand kilometers. Don’t rush to get upset if you weren’t able to notice it at that moment - you might have been hampered by light clouds on the horizon or you yourself were a little miscalculated with the direction. The star will move faster, glow brighter, and within a minute it will be much easier to find it. The station will reach a maximum altitude of 40 degrees in 22:47:43 , being almost to the south in azimuth. At this moment, the ISS will be located just below the star Altair, comparable in brightness to Venus, and angular velocity- with a jet plane. The distance to it will be about 600 km. Then the ISS will descend, moving to the east, and in 22:48:52 will enter the shadow of the Earth. Due to the presence of the atmosphere, the brightness of the station will not drop instantly. It will gradually fade away over ten seconds. Particularly attentive observers will notice that the ISS will turn red before going dark. After all, at this moment the astronauts on board will see the sun setting, and at sunset the sun's rays turn red. When the station is finally out of sight, look to the east and as a bonus, you'll see the moon rising.
Note: The above times will be correct to the second for an observer on Red Square. If you are far from the center, there will be differences of a few seconds. For example in Reutov maximum height will be reached 2 seconds later. Entry into the shadow will, of course, occur simultaneously for all observers.
Another less convenient passage for observations will occur one orbit earlier, at 21:11 . You can try to observe it first, but at 9 pm it is still quite light and the ISS will be difficult to spot against the light sky. In addition, the station will rise only 28 degrees.
How to take a photo or video of the ISS?
If you are going to observe the ISS for the first time, then I recommend not to be distracted by the photo yet. Better look with your eyes, get an idea of the brightness and speed. Next time, for example tomorrow, you can go out with a camera. Set the long exposure to 10-30 seconds. Adjust the aperture and sensitivity so as not to overexpose the sky, but at the same time so that the stars are visible. Mount the camera on a tripod and point it at the part of the sky where the flight is expected to occur. A few minutes earlier, you can take a test shot to make sure, using the stars as a guide, that the desired area of the sky is captured in the frame. As a result, you can get a frame like this (the photo is not mine, I found it on Google Images).
If you expect to fly near the Moon, you can catch an interesting shot. For example, this is what I got:
In dynamics it looked like this (shot on a Panasonic HDC-SD90 compact video camera).
What about the transits of the Moon and the Sun shown at the beginning of the article?
Recently, news portals circulated the news that NASA published unique photographs of the ISS against the backdrop of the Moon. Even on Giktimes about this. In fact, there is nothing unusual in that photo, you can verify this by searching keywords "iss transit" in Google Images. On the first try, I managed to take similar photos and videos with fairly modest equipment (the same as what I used in the article):
It's best to watch the video in full screen mode:
The main problem here is that the shadow (or rather penumbra) cast by the ISS from the Sun or Moon is only a few kilometers in size. In a randomly chosen place, such a phenomenon happens extremely rarely, so you will have to wait for the right moment, get into a car and drive several tens of kilometers. To find out when and where to go, you can use the calsky.com service. There you can get a map showing where the shadow of the ISS will pass in the next couple of days. Here, for example, is a fragment of a map of the nearest transits on the Moon.
Conclusion
I hope that thanks to this article, many readers will go outside tonight and look at the sky. I invite you to share your impressions in the comments!