WEBVTT FILE 1 00:00:00.000 --> 00:00:06.190 Recent observations from the Hubble Space Telescope show that Neptune's clouds are almost 2 00:00:06.190 --> 00:00:08.880 completely disappearing! 3 00:00:08.880 --> 00:00:14.019 Astronomers report that their continual monitoring of Neptune’s weather uncovered a link between 4 00:00:14.019 --> 00:00:19.750 its shifting cloud abundance and the 11-year solar cycle, in which the Sun’s entangled 5 00:00:19.750 --> 00:00:23.359 magnetic fields drives solar activity. 6 00:00:23.359 --> 00:00:30.640 When activity on the Sun increases, more intense ultraviolet radiation floods the solar system. 7 00:00:30.640 --> 00:00:35.040 Astronomers found that two years after the solar cycle’s peak, the number of clouds 8 00:00:35.040 --> 00:00:37.300 on Neptune increases. 9 00:00:37.300 --> 00:00:42.809 The link between Neptune and the Sun’s activity is surprising to planetary astronomers because 10 00:00:42.809 --> 00:00:50.110 Neptune is the outermost major planet, where sunlight is 1/900th the intensity Earth receives. 11 00:00:50.110 --> 00:00:56.010 To monitor the evolution of Neptune’s appearance, astronomers analyzed Hubble Space Telescope 12 00:00:56.010 --> 00:01:05.549 archival observations beginning in 1994, Keck Observatory images taken from 1994 to 2022, 13 00:01:05.549 --> 00:01:10.890 and Lick Observatory data from 2018 to 2019. 14 00:01:10.890 --> 00:01:17.250 The combined data will enable further investigations into the physics and chemistry that lead to 15 00:01:17.250 --> 00:01:22.220 Neptune’s dynamic appearance, which in turn may help deepen astronomers’ understanding 16 00:01:22.220 --> 00:01:26.770 not only of Neptune, but also of planets beyond our solar system. 17 00:01:26.770 --> 00:01:36.663 "Follow us on social media @NASAHubble"