In this most excellent 100th episode of Exocast from the team we bring you the latest in exoplanet research and news.

Hannah and Andrew cover news from the TRAPPIST system. Hannah will dive into the JWST results that have come out about this very famous system of seven Earth-sized rocky planets. Two papers look to the mid-infrared to measure the light directly from the planets b and c in emission – finding that they likely do not have an atmosphere possibly stripped by their stars radiation. The first spectroscopic measurements of TRAPPIST show that the star itself is going to be the “star” of the show with stellar contamination dominating the data. But we remain optimistic! 5 more planets await their observations and there is much to learn about this small cool star.

Andrew covers a paper that discusses the feasibility of detecting some biosignatures from TRAPPIST-1 d and e using JWST. This “experimental sandbox” for astrobiology makes TRAPPIST the perfect place to start. The theoretical studies uses a climate model to ask the question: what could we see if it was there? The model looks for methane, carbon dioxide, oxygen, ozone, methyl chloride, and methyl mercaptan; with methane and carbon dioxide pair being the best combo to suggest something out of equilibrium possibly caused by life. But is the question we should be asking, is this the right system to look for life at all? – what do you think?

Hugh then takes us back to formation in a dramatic fashion with an astronomical mystery. A young star has been dimming and almost disappeared for over a year with variations in the starlight over nearly 1000 days. The question simply is: What is going on? It is almost always something to do with dust. This can be seen over different wavelengths showing the dust interacting with the light. But in this case the exciting new result is that about 3 years before the dimming happened, a bright event was seen in the system. What the team found through simulations suggest that there was a giant collision of planets in that system that created the bright event and then the debris field blocking the light. Space is really remarkable!

100 episodes is a huge milestone and as always Hugh, Hannah, and Andrew could not do this show without you! Thank you for listening.

Exocast is edited by Fergus Hall. You can help support Exocast and the team at BuyMeACoffee.com/exocast, and get yourself some Exocast merch at exocast.threadless.com