Projects My specific research experience is with Jupiter's clouds and the gases that form them. This topic relates to a number of other areas of planetary research. Most importantly, since the cloud forming gases were delivered to Jupiter by planetesimals accreted during the giant planet's formation, these gases are also tracers of planetary formation. And observing clouds and cloud-forming gases with remote sensing is an effective way to study the dynamics of Jupiter's atmosphere. There may also be a link between stratospheric photochemistry and Jovian clouds, as nitriles and hydrocarbons precipitate downwards and mix with ammonia hazes in the upper troposphere.
	JUPITER'S GLOBAL UPHEAVAL G485 Dramatic changes in Jupiter's observable cloud patterns (in both southern and northern hemispheres) took place beginning in 2006. Nobody knows what causes Jupiter's global upheavals. The last upheaval took place in 1988-1990. Along with observers and theorists including Imke de Pater, Chris Go, Augustin Sánchez-Lavega, Glenn Orton, and Phil Marcus, I am searching for answers to questions about the causes and effects of upheaval-related phenomena. The images to the left show one of the changes: a drop in the cloud density close to the equator, darkening the equatorial zone. My 2007 AGU poster (below) discusses how this cloud change could be used to measure the source of Jupiter's equatorial tropospheric haze. Many of the other features and changes associated with the upheaval are discussed in Chris Go's DPS poster (below). Wong (2007) AGU Sánchez-Lavega et al. (in press) Nature Go et al. (2007) DPS
	RED SPOT JR. G480 Collaborator Chris Go was the first to notice in early 2006 that White Oval BA had become Red Oval BA, and some people nicknamed the storm "Red Spot Jr." Our team, led by Imke de Pater, was one of two that were awarded HST Director's Discretionary time to image the Red Oval, and collaborator Xylar Asay-Davis retrieved very precise velocity fields using the high-resolution HST/ACS/HRC images that were processed and deprojected by Sean Lockwood and me. Several papers are in the works discussing the dynamical implications of these data, justifying the prediction by collaborator Phil Marcus that Jupiter would begin to show signs of undergoing a climate change, after three white ovals merged between 1998 and 2000 to form Oval BA. de Pater et al. (2007) HST report, Hubble 2006: Science Year in Review. Marcus et al. (2006) DPS Asay-Davis et al. (2006) DPS Shetty et al. (2006) DPS Go et al. (2006) DPS, and Chris Go's Jupiter site HST press release Keck press release UC Berkeley press release Astronomy Picture of the Day, 2006-05-05
	TITAN'S DRIZZLE G454 With Máté Ádámkovics I am researching a "morning drizzle" in Titan's atmosphere. This important part of the methane cycle on Titan--analogous to the hydrologic cycle on Earth--involves ground-based hyperspectral adaptive-optics imaging on some of the world's largest infrared telescopes. Ádámkovics et al. (2007) Science
	COMPREHENSIVE JUPITER AMMONIA MAPPING PROJECT G470 For this project, we collected several datasets to quantify spatial variations of ammonia gas concentration on Jupiter. HST/NICMOS data provided a high-resolution look at Jupiter's equatorial region, and found distinct patterns of ammonia variations in the haze layer and the upper cloud layer. IRTF observations near 5 μm detected breaks in the upper cloud decks, which were strongly correlated with low ammonia gas opacity in longitudinally-resolved VLA radio maps at wavelengths of 2 and 3.6 cm. Wong and de Pater (2005) DPS Wong et al. (2006b) DPS
	NH3 ICE SPECTRAL SIGNATURE G400, G410, G411, G468 Although it was a challenging exercise in noise-level data analysis, we managed to make a robust first detection of the ammonia ice spectral feature at 10 μm in the thermal infrared. After submitting the paper, we realized that Cassini CIRS data from focal plane 4 (FP4... much lower s/n) could be used in the 10-μm spectral window, even though it was outside the nominal frequency range. The map at left was generated with FP4 data, and regions with a strong NH3 signature are shown as green-yellow. Based on this preliminary work, which was presented at the 2003 DPS in Monterey, the FP4 data seem to be clean enough to someday construct 2-D maps of ammonia ice on Jupiter. One possible explanation for the general lack of ammonia ice spectral signatures in Jupiter's atmosphere is that "soot" produced by stratospheric photochemistry drifts down and contaminates fresh ammonia ice particles, masking their spectral signatures. Collaborator Kostas Kalogerakis is conducting laboratory experiments designed to measure this effect and other details relevant to the ices that form outer planet clouds. Wong et al. (2004a) Atreya et al. (2005) Kalogerakis et al. (2006) DPS
	TROJAN ASTEROIDS G462 Binary asteroids are the holy grail of the study of asteroid interiors, because measuring their orbits yields the mass of the system, which leads to a determination of the asteroids' density. Trojan asteroids, which orbit two jovian "months" ahead and behind Jupiter, are thought to be remnants of the same population of planetesimals that formed the outer planets. 617 Patroclus and 624 Hektor are the only known binary Trojans. Franck Marchis and I discovered Hektor's companion during an adaptive optics observing run at Keck. We have also been accumulating lightcurve data on many Trojan asteroids. Marchis et al. (2006a) Nature Marchis et al. (2006a) DPS
	JUPITER'S RING G451, G464 One of my first projects upon arriving at Berkeley to work with Imke de Pater was to reduce near-infrared spectroscopic observations of Jupiter's ring taken with NIRSPEC at Keck. We have a paper in the review stage discussing results from this data and from imaging photometry. I also attempted to measure thermal radiation emitted from elusive larger bodies in Jupiter's ring using the ultra-sensitive Spitzer Space Telescope, but unfortunately those data seem to be awash with stray light from the much brighter Jupiter. Wong et al. (2004c) Wong et al. (2006b) Icarus
	COMPOSITION OF JUPITER'S ATMOSPHERE G320, G321, G323 I spent years in Michigan working with a little stream of some 7000 integers or so. These numbers from the Galileo Probe Mass Spectrometer were the only direct in situ record of Jupiter's atmospheric composition, between the levels of about 0.5 and 22 bar. From this data we measured nitrogren and noble gas isotopic ratios, cosmochemical constraints that are difficult or impossible to collect remotely. We measured strange profiles of the cloud forming gases, and struggled to explain the "jovian desert" the probe had descended into. We also measured surprisingly high levels of complex hydrocarbons... at levels as deep as 10 bar !! These chemicals are thought to form in the rarified stratosphere and drift down in the troposphere on parametrized eddies; it seems impossible that the high concentrations measured could have been stratospherically generated. The favored exuse for abundant hydrocarbons in the data is that poorly determined calibration constants may be giving us false high values. Or perhaps, somewhere in or on the probe, there was a source of hydrocarbon gas. The probe did not carry an imaging camera, so even if a hydrocarbon spray from a jellyblimp savagely slain by a razorwing had splattered the GPMS inlets, we would have had no sign that anything was amiss, other than elevated hydrocarbon levels. Wong et al. (2007) in press Wong et al. (2005) Wong et al. (2004b) Roos-Serote et al. (2004) Atreya et al. (2003) Owen et al. (2001) Hunten et al. (2000) Atreya et al. (1999) Jellyblimps and swordtails taken from Our Universe.