Entertaining Astronomy - Mercury Facts

In continuation of my post about the Moon , so warmly received, I cannot but continue the topic and present the following material about Mercury:

• Mercury is the closest planet to the Sun.
• The average distance to the Sun is 57.91 million km (0.387 AU), i.e. three times closer than Earth .
• Mercury receives 7 times more solar energy than the Earth.
• The Merkurian solar day lasts two Mercurian years (a day is longer than a year due to the unusual ratio of orbital speed and rotational speed around its axis).
• Mercury's orbital speed is the highest among the planets - 47.87 km / s (1.64 Earth).
• Volume - 6.08272 · 10 ¹⁰ km ³ , which is 0.056 Earth.
• The radius is only 2439.7 km, which is even smaller than the radii of the satellite of Jupiter Ganymede and the satellite of Saturn Titan .
• Thus, Mercury is the smallest planet in the Solar System (yes, yes, Pluto, although smaller, is no longer considered a planet).
• The mass of Mercury is 3.3022 · 10 ²³ kg (0.055 Earth).
• Acceleration of gravity - 3.7 m / s ² or 0.377 g.

Interesting

Despite the fact that the orbits of Mars and Venus are closest to Earth orbits, it is Mercury that most of the time is the planet closest to Earth.

Mercury has an extremely rarefied atmosphere, whose pressure is 5 · 10 ¹¹ times less than the pressure of the earth's atmosphere. In such conditions, the atoms often collide with the surface of the planet than with each other.

There are no seasons familiar to us earthlings on Mercury. This is due to the fact that the axis of rotation of the planet is at right angles to the plane of the orbit. As a result, near the poles there are areas where the sun's rays never fall. It is in these areas that ice is located, despite the fact that Mercury is closest to the Sun among all planets.
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The surface of Mercury is in many ways reminiscent of the moon - it is dotted with many craters. But on Mercury there are numerous jagged slopes (escarpments) stretching for hundreds of kilometers. They were formed during compression, which accompanied the cooling of the planet, as a result of which the surface of Mercury decreased by 1%.

Mercury has a comet-like tail more than 2.5 million km long, whose apparent length for an observer from Earth is about 3 °.

The Hubble telescope will never turn toward Mercury. Its design does not allow to observe objects near the Sun and, when trying to do this, the equipment will be irreversibly damaged.

On Mercury in one day there can be two sunrises. This is possible because in the area of ​​the orbit near the perihelion for about 8 days the speed of the orbital motion exceeds the speed of rotational motion. As a result, the sun in the sky of Mercury stops, and begins to move in the opposite direction (see the Joshua effect).

Mercury is a rather complex object to observe in the high latitudes of the Earth due to the fact that it is always observed in the dawn - morning or evening - against the background of the twilight sky, and rather low above the horizon (especially in northern latitudes). There is a story that Nicolaus Copernicus , who observed astronomical objects in the conditions of northern latitudes and the misty climate of the Baltic states, regretted that in all his life he had not seen Mercury.

Of all the planets visible to the naked eye, only Mercury never had its own artificial satellite. The launch of AMC MESSENGER into the orbit of Mercury is scheduled for 2011.

About Mercury was written by such authors as Isaac Asimov “The Great Sun of Mercury”, Boris Lyapunov “Nearest the Sun” and Francis Karsak “The Escape of the Earth”. In addition, in the anime " Sailor Moon " the girl is represented by the warrior-girl Sailor Mercury, she is Ami Mitsuno ^ _ ^

Compile information from, for the most part, Wikipedia , and other astronomical sites.