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Space Mysteries 9: What flies in the sky? It's a comet, not a satellite

Two types of objects that have nothing to do with each other, except for the fact that they move in the sky - for some reason in the cartoons the comets sometimes move at an enormous speed when they cross the sky. However, in reality the change can be seen only within 24 hours. Satellites fly fast on the other hand

Avi Blizovsky

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Are artificial satellites visible to the naked eye?

The answer to this is positive. In fact, many people are surprised when an object orbiting the earth at a height of hundreds of kilometers can be seen without binoculars or a telescope.
Since the launch of the first Sputnik in 1957 (Sputnik was nicknamed the "Communist Red Star" by the Americans) until today, the number of satellites in space has increased greatly. Today there are over ten thousand metal lumps in the sky orbiting the Earth, although not all of them are active satellites. Actually the number of active satellites is about 600. Since the days of the Soviet Union, many hundreds of final stages of packages and cylinders of rockets from the Cosmos program alone have been orbiting the earth. Some of them can shine like a medium star.
The British astronomer Desmond King-Hele once remarked that a satellite "looks like a star that has left its group and moved to another region of the sky. If you go outside in the evening or early morning, chances are you won't have to wait more than 15 minutes before you see a satellite. Most of them are too blind to be seen with the naked eye, but a few hundred are big enough (over 7 meters long) and low enough (160-640 km above the surface of the earth) that they can be seen.
Satellites are visible at night because they reflect sunlight. A satellite that enters the Earth's shadow immediately disappears from the observer's eyes and continues on an invisible path until it reappears in full sunlight.
The International Space Station and the Space Shuttle are among the bright bodies circling the Earth at an average height of about 400 km, and they can appear to move as fast as an airplane taking off, sometimes taking 3-4 minutes to cross the entire sky. They are very easy to mistake for aircraft lights, as their brightness can rival that of Jupiter at its peak.
Iridium satellites are considered the brightest satellites, the satellites can be exposed from luminosities of 1 to -8, and their brightnesses are gradual.


Why don't comets fly in the sky?

Before answering the question, think about this - have you ever seen the moon cross your line of sight like a meteor? Although the moon orbits the earth at a speed of over 3,200 km/h, at an average distance of 380,000 km from the earth, its peripheral speed is hardly noticed.
Similarly, although the comets visible to the naked eye move at a speed of tens of thousands of kilometers per hour within the inner solar system, their distance from the Earth is measured in tens of millions of kilometers. So its movement against the background stars from night to night appears very slow.
Comets do move in the sky as the moon and planets do, not as you see a meteor falling to earth.
Astronomer

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