The greatest voyage

Forty years have passed since the start of the Voyagers, who went on their great campaign. The first, August 20, 1977, was launched by Voyager-2, and on September 5, Voyager-1 flew. The epithet "great" in this case is not an exaggeration. There are still no equal in the study of the solar system for the “Voyagers”. They brought us a kind of insight. For the first time, we saw all the giant planets close-up, their rings, their various amazing satellites-worlds, which people had only the most general idea of.

Of course, then there were “Galileo”, “Cassini”, “New Horizons”, they sent higher quality data, made their discoveries (which are, for example, the methane seas of the titanium, open “Cassini”!), But this was already a systematic development of busy borders.

The flight of Voyader-2 is especially fantastic: four giant planets with satellites in one fell swoop-Jupiter, Saturn, Uranus and Neptune, and the last two has not yet been visited by any earthly apparatus (only in the 2020s, new expeditions will send there). Voyager-1, in turn, went down in history as the fastest and most remote artificial object from the Earth-it was the first to reach the boundaries of the heliosphere (in August 2012). Both devices, most amazing, continue to work and transmit valuable scientific data.

Burial-vulcanic Io

The first photos of the Io made by Voyagger-1 were a complete surprise, a kind of revelation. The world where huge volcanoes erupt right before our eyes, which is all covered with lava and gray. In the first picture is the IO disc with the erupting volcano Loki, which is a little behind the limb. Below, a little on the left - the pele volcano: a large circle of settled material thrown out by the volcano, and the black dot in the center is the pole. The reason for the violent volcanism is trivial-the heating of the bowels from a tidal interaction with Jupiter, which occurs due to the easy elongation of the orbit of the IO.

In the second photo, taken with the best resolution, the Volcano Pele is already erupted (to the right and above the center of the picture). The emission itself in this case is too ephemeral and not visible against the background of the planet, but it manifests itself well against the background of the dark sky to the right. The ejection height is about 300 km.

Sickle Europe

A picture (more precisely, a mosaic of pictures) of Europe, made by Voyager-2. Another revelation. The planet in the ice shell with faults stretching for thousands of kilometers. By the way, the same faults in the form of double ridges are visible in the picture of Triton. There are a lot of signs that under the ice is a water ocean in which life is even possible.

Satellite Saturn Enzelad

504 km in diameter. August 25, 1982. From a distance of 120 thousand km.

Satellite Saturn Tefiya (Tetis)

The surface is dotted with craters (craters come across with a diameter of more than 40 km).

Miranda

This image (from Voyader-2) of the closest and smallest (235 km) of the five largest Uranus satellites was obtained shortly before the maximum rapprochement with him. A highly crossed terrain with high relief (right) alternates with lowlands and ravines.

January 24, 1986. Distance - 30 thousand km.

Uranus and Neptune

The blue color of Neptune and Uranus has the same nature as the blue color of the sky - Raleevsky scattering, red absorption with methane is added to it. The clouds on these planets are deeper than on yellowish Jupiter and Saturn, hence the difference in color. The upper clouds on Neptune - at the pressure level of 1.2 bar - deeper than the surface of the earth; In uranium - even deeper. The probable cause is weak convection in the atmosphere, especially in uranium. According to Voyader-2, there is no noticeable internal heat source in Uranus or Neptune. But if Uranus is generally devoid of visible details, then there are several on Neptune. First of all, a large dark spot, a vortex-anticyclone, observed for years (but not centuries, like a large red spot of Jupiter)-Hubble now sees it. To the south there is a second dark spot with a light core. Still - the latitudinal stripes of clouds and the cloud triangle nicknamed the "scooter". All details move with different angular velocities, and the fact that in the picture they were on close longitude are an accident. The speed of the clouds of Neptune reaches 2100 km/h.

Uranus rings

View “with the rear lighting” demonstrates the continuous distribution of small particles throughout the system of rings. January 24, 1986. Range - 237 thousand km.

In December 1985-January 1986, Voyager-2 opens a number of new companions of Uranus: Pak, Juliet, Portion, Cressida, Desdemona, Rosalind, Belinda, Perdit, Cordelia, Ophelia, Bianca (of course, they received their names much later).

Sitnik Uranus Ariel

The most detailed photograph of this satellite, taken by Voyader-2, demonstrates numerous faults and valleys. The diameter of Ariel is 1200 km, its southern hemisphere was removed. January 24, 1986. Distance - 130 thousand km.

Satellites Uranus Oberon and Titania

Covered by a large number of craters, the surface of Oberon (1523 km) is probably preserved since its formation. Much larger craters are found here than on Ariel and the largest satellite of Uranus Titania. Some craters have radiation emissions, similar to what is on Callisto. In the picture on the right, a mountain is visible, which rises above the surrounding area 6 km. January 24, 1986. Range - 660 thousand km.

Tall clouds of Neptune

The latitudinal clouds of Neptune, taken two hours before the maximum rapprochement with the planet on August 25, 1989 (5 thousand km above the northern pole). Due to the low sun, the vertical relief of the clouds is visible.

The width of the cloud strips is 50-200 km. Height - tens of kilometers. On the same day, after a few hours, Voyager-2 went 40 thousand km from Triton, over his southern hemisphere.

Neptune ring system,

Shown in two expositions lasting about 10 minutes each.

Triton

Triton is a fellow Pluto. They are at comparable distances from the sun and are almost the same in size (the triton is slightly larger - 2707 km, Pluto - 2374 km). The significant difference, however, is that Triton is warming from the inside due to a tidal interaction, since it is captured by a planet-giant. This satellite has a nitrogen atmosphere with barely noticeable clouds that are visible in some pictures on the limb (Pluto - too).

It is so cold on Triton (38 K) that the most nitrogen was scandalized on the surface in the form of ice. And most of the surface is covered with nitrogen ice. From above - a huge southern polar hat, probably covered with methane ice. Pink color is a product of the interaction of sunlight with methane.

The most interesting thing is dark stripes in the upper part of the picture. They are approximately parallel to each other and come from black dots. These are the so -called cryovulcans - outputs of jets of gas from the bowels, something like giant fumarol. The dimensions of dark trails are dozens, sometimes hundreds of kilometers. Something like soot flies with gas, which is postponed in the form of stripes - they are formed by the wind, which is felt even in the sparse atmosphere of Triton. Probably, “fumarolars” act when underground surface layers of volatile substances heat up due to seasonal warming.

At the bottom right is the “melon earth”, named after the characteristic pattern. Its origin is unknown. The hypothesis is discussed that this is the result of the stormy period of cryovulcanism: the liquid that is pleasing from the bowels, frozen, formed a pattern resembling a peel of melon.

It is possible that Triton also has an inner ocean, but not water, but from a mixture of water and ammonia - the temperature of the subsoil is unlikely to greatly exceed –100 ° C.

Giving tribute to the magnificent data of the “new horizons” on Pluto, it should be noted that nearly 30 years earlier the “Voyager-2” with the same success, but with much less attention of the media and society, investigated a similar and no less interesting object.

Boris Stern, Maxim Borisov
Photo NASA