The spacecraft was successfully launched to the planet Hema

After reaching its destination in 2011, the spacecraft will orbit the planet Mercury (Mercury, which despite its name is a planet and not a Saturn planet) for a year, during which it will study the planet's atmosphere, its composition and structure.

On its way to Mercury, the NASA spacecraft will complete 15 orbits around the Sun.

During its 7.9 billion kilometer journey, the spacecraft will pass once by Earth, twice by Venus and three times by Mercury, before entering orbit around the innermost planet in the Solar System.

The spacecraft will collect information on the composition and structure of the planet Hema's crust, its geological history, polar regions, atmosphere, magnetic environment and composition of its core.

Mysterious world

Mission scientists hope that the $427 million (€234 million) operation will help solve some of the mysteries surrounding the mysterious world of the planet Hema.

Astronomers have known for a long time that Mercury - the planet with the highest density in the solar system - is composed of about two-thirds of iron. However, the reason why this planet became so rich in this metal relative to the other planets is unknown.

Some scientists think that Mercury was once rocky, but lost its mantle due to exposure to solar winds or some kind of massive collision.

Sean Solomon, science director for the mission, said he was interested in understanding why the inner planets of the solar system (Humper, Venus, Earth and Mars) are so different from the outer planets such as Jupiter and Saturn.

To that end it was important to "investigate the most extreme example of this variability, and that example is the planet Mercury," explained Dr. Solomon.

Also, Mercury is the only inner planet other than Earth that has a global magnetic field. Scientists hope to learn how it is formed.

fire and ice

However, one of the intriguing mysteries of Mercury is the presence of ice on the planet's surface.

On a planet whose surface temperature at the equator can reach 450 degrees Celsius (about 840 degrees Fahrenheit), the ice must move away from the sun and find shelter in shadowed craters at the poles.

Radio telescopes on Earth have detected signs of ice in craters in shaded areas at high latitudes, where the temperature remains below minus 184 degrees Celsius (minus 300 degrees Fahrenheit).

The Mercury Messenger carries with it seven scientific instruments, which will study the characteristics of its target. The spacecraft will operate at room temperature behind a screen of a heat-resistant ceramic structure.

The spacecraft, which weighs 1.2 tons, carries with it a heat radiation system, and it will pass quickly over the hottest areas of the planet to avoid long exposure to the strong heat, reflected from the hot surface of Mercury.

Mercury is probably the least studied of the rocky planets. This group also includes Venus, Earth and Mars.

Most of what scientists know about Mercury comes from the Mariner 10 spacecraft, which flew by the planet three times in 1974 and 1975. However, Mariner 10 collected detailed data on only less than half of the planet's surface.

If everything goes well, the "Messenger" spacecraft will be launched this morning at 9:16:11 (Israel time). If the launch is canceled for any reason, NASA will be able to return to normal in the next 12 days, in the short "window" (12 seconds) that will open every day for the launch of the unmanned spacecraft, whose route to the planet Hema (Mercury) is considered complex.

After the launch, the spacecraft will embark on a long journey that will last six and a half years and about eight billion kilometers, after which it will begin its one-year mission: the study of the planet, which may unravel the mystery of the formation of the solar system.

Messenger ("messenger"), named among other things after the Greek god Mercury - the agile messenger of the gods in Roman mythology - will be the first spacecraft to enter orbit around the planet Mercury. The last time a spacecraft visited the Hema region was 30 years ago, when "Mariner 10" passed by the planet three times, photographed it several hundred times and continued on its way.

Mercury is one of the mysterious and unexplored planets in the solar system. The fact that it is the closest star to the Sun makes it particularly hostile: the spacecraft will have to deal with extreme temperatures of 427 degrees Celsius on the bright side, and minus 183 on the dark side. It is made of solid rock riddled with craters and moves at a dizzying speed of 48 kilometers per second, completing a revolution around the sun once every 88 days. On the other hand, it rotates annoyingly slowly around its axis, and one day on its surface equals 176 days on Earth. Its proximity to the Sun makes it difficult to distinguish it from Earth. In fact, it can only be observed a few weeks a year, a few minutes before sunrise or after sunset.

Due to the extreme heat around Mercury, Messenger will be exposed to sunlight for 30 minutes at a time. The spacecraft, which weighs 1.2 tons, is coated with a special ceramic coating that will protect it and the seven scientific instruments mounted on it, including a gamma ray detector that will try to find out the composition of the materials on the surface of the planet Hema. This detector is cooled, using a special system of the Israeli "Recor" company, to a temperature of minus 200 degrees so that it is sensitive to radiation.

Mariner 10 provided intriguing data about the planet Mercury regarding its high density and large iron core. These data may be related to the time of the formation of the planet Hema; Close to the formation of the solar system itself. MESSENGER's role will be to send new images and provide data that will shed light on the history of the planet and hence also on the entire solar system. The scientists hope they can also answer the question of whether there is ice on its poles.

NASA invested 427 million dollars in the construction and launch of Messenger, not before facing several problems, first of all the weak gravity of the planet Mercury, which requires Messenger to reach it at the appropriate speed and with the precise timing to be trapped in orbit around it.

To achieve this goal, the scientists are playing a game of "interstellar billiards," in which they use the gravity of Earth, Mars, and Mercury to accelerate Messenger on its way to Mercury, while special rockets mounted on the spacecraft will act as brakes.