When observed for the first time, around 1665, it was simply a strange structure that Jupiter displayed to the first telescopes that merited such a name: a large red-colored spot that covered almost the entire visible hemisphere. From that time, there have been many attempts to explain just what that mysterious spot is, especially when it was understood that, since Jupiter is mainly gaseous, what we were seeing could not be a physical form on its surface. In three hundred years, the spot has changed position many times and its dimensions have varied from a minimum diameter of 25 000 kilometers to a maximum of about 50 000. The mystery that had to be explained was how the structure of a body with such a tenuous composition continues for so long on its surface. An initial explanation was that it was like a "raft": perhaps an enormous slab of solid material floating on Jupiter's surface of dust and gas. Like a raft, it could drift or partially sink, thus apparently changing its dimensions. A second attempt to explain the phenomenon stated that there had to be an obstacle in the lower part of Jupiter's atmosphere that interrupted the atmospheric circulation. Above this was a column that remained in a more or less stationary position. To discover the truth, the electronic eyes of the Pioneer and the Voyager probes were focused with great curiosity on this structure as well as on the surface of Jupiter in general. The result is that the Great Red Spot, though it still has incredible dimensions, does not appear to be so exceptional as it seemed in the past. In fact, the surface of Jupiter is roughly divided into a series of white-yellow and red bands, parallel to the equator. Within these bands, areas such as the Great Red Spot, though much smaller, are rather common.
When observed for the first time, around 1665, it was simply a strange structure that Jupiter displayed to the first telescopes that merited such a name: a large red-colored spot that covered almost the entire visible hemisphere. From that time, there have been many attempts to explain just what that mysterious spot is, especially when it was understood that, since Jupiter is mainly gaseous, what we were seeing could not be a physical form on its surface. In three hundred years, the spot has changed position many times and its dimensions have varied from a minimum diameter of 25 000 kilometers to a maximum of about 50 000. The mystery that had to be explained was how the structure of a body with such a tenuous composition continues for so long on its surface. An initial explanation was that it was like a "raft": perhaps an enormous slab of solid material floating on Jupiter's surface of dust and gas. Like a raft, it could drift or partially sink, thus apparently changing its dimensions. A second attempt to explain the phenomenon stated that there had to be an obstacle in the lower part of Jupiter's atmosphere that interrupted the atmospheric circulation. Above this was a column that remained in a more or less stationary position. To discover the truth, the electronic eyes of the Pioneer and the Voyager probes were focused with great curiosity on this structure as well as on the surface of Jupiter in general. The result is that the Great Red Spot, though it still has incredible dimensions, does not appear to be so exceptional as it seemed in the past. In fact, the surface of Jupiter is roughly divided into a series of white-yellow and red bands, parallel to the equator. Within these bands, areas such as the Great Red Spot, though much smaller, are rather common.
