Hubble images revealed in April taken with WFPC-2 over a period of weeks in October and November 1994 show changing weather conditions on Neptune. Neptune's atmosphere changes over a matter of days. The Great Dark Spot seen by Voyager 2 in 1989 has gone away; its name is now "Great Dark Spot 1989." A new dark spot, called "Great Dark Spot 1994," is now visible in Neptune's northern hemisphere, a mirror image across the equator of the prior dark spot. Its image is much less clear than that taken from Voyager 2, but it does show; given Neptune's current tip away from Earth, it appears on Neptune's limb.
An infrared image taken at Mauna Kea on September 10/11, 1994, by Keith S. Noll, Diane Gilmore and David R. Soderblom at the NASA Infrared Telescope Facility. Filters between 1.2 and 2.2 microns were used. The images were taken with a 256x256 pixel infrared array called NSFCAM. The images appeared in Sky & Telescope for March 1995, p. 12. Clouds show on Neptune, which was only 2.3 arc sec across. Triton appears at upper left.
photo courtesy K. Noll, D. Gillmore and D. Soderblom