(_Range to Jupiter, 5.9 million kilometers_). At 6:33 a.m., at a range of 86 R_J, Voyager 1 finally reached Jupiter’s bow shock. But by 12:28 p.m. the solar wind had pushed the magnetosphere back toward Jupiter, and Voyager was once more outside, back in the solar wind. Not until March 2, at a distance of less than 45 R_J, would the spacecraft enter the magnetosphere for the final time. At 11 a.m. the first daily briefing to the press was given. “After nearly two months of atmospheric imaging and perhaps a week or two of satellite viewing, [we’re] happily bewildered,” said Brad Smith. The Jovian atmosphere is “where our greatest state of confusion seems to exist right at the moment, although over the next several days we may find that some of our smirking geology friends will find themselves in a similar state. I think, for the most part, we have to say that the existing atmospheric circulation models have all been shot to hell by Voyager. Although these models can still explain some of the coarse zonal flow patterns, they fail entirely in explaining the detailed behavior that Voyager is now revealing.” It was thought, from Pioneer results, that Jupiter’s atmosphere showed primarily horizontal or zonal flow near the equatorial region, but that the zonal flow pattern broke down at high latitudes. But Voyager found that “zonal flow exists poleward as far as we can see.” Smith also showed a time-lapse movie of Jupiter assembled from images obtained during the month of January. Once each rotation, approximately every ten hours, a color picture had been taken. Viewed consecutively, these frames displayed the complex cloud motions on a single hemisphere of Jupiter, as they would be seen from a fixed point above the equator of the planet. The film revealed that clouds move around the Great Red Spot in a period of about six days, at speeds of perhaps 100 meters per second. The Great Red Spot, as well as many of the smaller spots that dot the planet, appeared to be rotating anticyclonically. Anticyclonic motion is characteristic of high-pressure regions, unlike terrestrial storms. Smith noted that “Jupiter is far more complex in its atmospheric motions than we had ever imagined. We are seeing a much more complicated flow of cyclonic and anticyclonic vorticity, circulation. We see currents which flow along and seem to interact with an obstacle and turn around and flow back.” There is a Jovian jet stream that is “moving along at well over 100 meters per second. Several of these curious little dark features that appear to be small brown spots near Jupiter’s north temperate region have been seen to overtake one another and gobble each other up. And then they occasionally spit out a piece here and there as they move along.” Thursday, March 1.