out from the Earth and with AIS Pioneer and Voyager show that their
atmospheres predominantly consist of hydrogen and helium which
chemically brings them closer to the Sun rather than to the planets of the
earth type.
In Jupiter’s atmosphere molecules of methane, ethane, ammonia,
acetylene, etc. have been registered. The presence of these compounds
and water vapours in its upper layers suggests a possible chemical
evolution on that planet. Titan — the biggest satellite of Saturn, raises an
exceptional interest. It is the only natural satellite in the Solar system
with a dense atmosphere containing nitrogen (90%), methane (1—10%),
certain amounts of ethane, ethylene, acetylene, etc. Its atmospheric
pressure is 1.6 times the Earth’s one. But at temperatures of minus
180°C it will hardly prove to be the lucky place for another presence of
life in the Solar system.
Uranus, Neptune and Pluto. What is typical of these planets is that
they receive less light and heat from the Sun. Being so remote from the
Earth, they are much less studied. A presence of mainly hydrogen and
helium in their atmospheres has been recorded by spectrometric studies.
The low temperatures of the order of minus 180—200°C for Uranus and
Neptune (putative data) and minus 220°C for Pluto do not raise hopes for
life on them.
The data from the flight of Voyager 2 (launched in September 1977
and reached Neptune on 1st Septembre 1989) showed conditions
exceedingly unfavourable for life on that planet. Apart from the low
temperatures, ferocious storms with speed of about 1120 km/h rage on
Neptune. Its satellite Triton which has a gas envelope (800 km thick) of
nitrogen and methane proves to be the coldest place in the Solar system
— minus 240°C.
In conclusion I would resort to the statement of Oró et al. (1990)
who have closely followed the results from the investigations of NASA on
that problem: “We have no evidence of extraterrestrial life. It is difficult
however to conceive from a scientific point of view that “intelligent” life
on Earth is a singular phenomenon in the trillions of galaxies that
comprise the observable Universe”.
Scientific truth is strict and most often boring. That is why don’t like
it a considerable number of people who are not acquainted with the
means, ways and methods for its accomplishment and are inclined to
believe fantastic stories without any scientific foundation about unproven
or altogether non-existent phenomena and events. The Tungus
meteorite exploded on July 30th 1908 in the Siberian tundra has been for
decades presented as an explosion of a spaceship from another planet.
A huge number of books, journals and newspapers sensationally report
on UFO (Unidentified Flying Objects) sometimes even trying to provide
proofs with the testimony of eye-witnesses.