This event was predicted a year in advance, when the comet was discovered in orbit around the giant planet, so that the JCMT and essentially every other telescope in the world was able to plan to observe the event. It was fortunate for the Mauna Kea telescopes that this was so, because, as was noted in the August 1994 Newsletter, the weather was atrocious during this week there being one hurricane and a tropical storm passing by. A single event might have been cancelled due to poor weather. Image not available yet Figure 1. A typical aspect of Jupiter's disk during the past six months.
North is up, East is left.
Within an hour of impact each site was clearly visible as the planet rotated. Even before this, optical and infrared telescopes were able to see the fireballs peeking over the limb, as hot gases were ejected into the stratosphere of the planet from the tunnel driven deep into the lower layers of the atmosphere by each fragment. However, while most of the visually exciting effects were recorded by CCD's and on film, Jupiter soon after became a day-time object, leaving the field to the radio telescopes. And now, as Jupiter once again can be seen at night, and the impact sites are much less visible, it also turns out that the most long-lasting effects are likely also to be those which can be seen by radio telescopes. For orientation purposes, the sketch in Figure 1 shows a typical face of Jupiter as presented to Earth during the July 1994 observations and, with only slight changes, throughout the follow-up observations described here.