DIX Planetary Science Seminar

A new class of exoplanets has emerged in recent years: the ultrahot Jupiters. These extremely irradiated gas giants are characterized by dayside temperatures higher than 2000 K, reminiscent of those found in stellar atmospheres. In this temperature regime, thermal dissociation and ionization turn most molecular species into atoms and ions, and clouds are unlikely to form. Additionally, space and ground-based observations have revealed the presence of strong thermal inversion layers in ultrahot Jupiters, in contrast with the noninverted thermal profiles of cooler hot Jupiters. Due to their clear atmospheres, high temperatures and frequent transits, ultrahot Jupiters have quickly become some of the most studied targets in the exoplanet field. From iron rain to extreme wind speeds, in this talk I will discuss recent findings in the exotic atmospheres of this booming exoplanet population, with a focus on the advances brought in by studies at high spectral resolution. Finally, I will outline some of the exciting opportunities that telescopes like the ELT and JWST will provide us with in our quest to understand the atmospheres and origins of ultrahot Jupiters.

During its first seven years of operation, the Sample Analysis at Mars Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected seven methane spikes above a low background abundance in Gale crater. The methane spikes are likely sourced by surface emission within or around Gale crater. Here, we use inverse Lagrangian modeling techniques to identify upstream emission regions on the Martian surface for these methane spikes at an unprecedented spatial resolution. Inside Gale crater, the northwestern crater floor casts the strongest influence on the detections. Outside Gale crater, the upstream regions common to all the methane spikes extend toward the north. The contrasting results from two consecutive TLS methane measurements performed on the same sol point to an active emission site to the west or the southwest of the Curiosity rover on the northwestern crater floor. The observed spike magnitude and frequency also favor emission sites on the northwestern crater floor, unless there are fast methane removal mechanisms at work, or either the methane spikes of TLS or the non-detections of ExoMars Trace Gas Orbiter cannot be trusted