Although the tradewind inversion is set to slowly breakdown over the next 12-24 hours, it will continue to keep the summit dry and stable for tonight. Unfortunately, there is a strong possibility that it will fall apart by tomorrow afternoon, leading to a fairly saturated atmosphere below 18 thousand feet and likely fog, ice and light flurries at the summit for tomorrow night and perhaps even Thursday night. The inversion is expected to recover near 8 thousand feet by Friday morning.
These inversions are changes in the gradient of the atmospheric temperatures - they tend to trap moist air below the 8000-foot level, leaving the summit dry and clear. If this inversion is blown away, the trap is no longer effective, hence the forecast of fog, ice and possible snow. So we're aware that tonight could be our last good shot at Jupiter, Io, Saturn and the galaxies for the next few nights. Plus we're hearing reports of a magnitude 8 earthquake off the Soloman islands and were worried about tsunamis in Hilo, but it sounds like all is fine on this side of the Pacific.
Moon tracking for the duration of the TEXES run,suggesting we'll see Io transit Jupiter tonight.
Next we moved to Jupiter, attempted to do an efficient run through of 8 different spectral settings. According to Sky and Telescope's handy tool, the GRS should transit the central meridian at 10:14 UT (our Jupiter observations began at 07:15 UT). It happened right on schedule. Our settings included the Q-band (for Jupiter's tropospheric temperatures); ethane, acetylene and methane (for stratospheric temperatures), and three low-resolution settings (for ammonia, phosphine and cloud-cover). The images in the low-resolution settings were stunning - we can make out rings around Oval BA and the GRS, but also the white ovals (WOs) to the south, and interesting morphology on the 5-µm hotspots in the North Equatorial Belt (NEB). Io was right in the middle of transit at 09:20 UT, but we had to stop our sequence at around 09:45 UT (near midnight) as the airmass was getting so high that the telescope was jittering all over the place.
|NASA Hubble Space Telescope image of the |
Antennae galaxies (NGC 4038 & 4039)
As we were integrating on these source regions, I took the opportunity to head outside with the night vision goggles for a stunning view of the stars and telescopes, truly breathtaking. I realised that Keck was using it's adaptive optics system with a laser guide star (e.g, reflecting laser light off a sodium layer 90 km high in the Earth's atmosphere). A long exposure shot with a Canon DSLR is shown below in black and white to bring out the contrast - the real laser light is red in colour, but is hard to capture with my camera!
|Photo of Keck's laser guide star, Orion top left, |
Jupiter far right, 11:40 UT on February 6th 2013.
|A better image of the Keck guide star from the HEASARC picture of the week.|