Reading Summary: Life in the Atmosphere of Venus? 77 unread replies.77 replies. Introduction In Autumn 2020 astronomers reported the apparent detection of a molecule called phosphine (PH3) in the clouds of Venus. This was potentially super exciting, because phosphine is associated with places on Earth where life is known to exist, even though a direct path for phosphine production by life is not yet known. The original discoverers tried to think of other non-life (abiotic) ways that phosphine might be produced in Venus’ atmosphere but weren’t able to come up with a good explanation, and so speculated that it might be due to life. However, as you’ve learned this week, the surface of Venus is inhospitable to even the most hardy examples of life as we know it. The cloud region of Venus is slightly more hospitable than the surface, with a more Earth-like temperature and atmospheric pressure. However, the clouds themselves are predominantly made of concentrated sulfuric acid, which, apart from the high acidity, also means that any water in the cloud droplets would not be available for life to use, making the cloud region something of a floating desert for organisms that require water. Given all the challenges to Venus life, a lot of other scientists---including Venus scientists, astronomical observers, and astrobiologists---were quite skeptical of the discovery, and set about to see if they could confirm, or disprove, the detection of PH3 and its interpretation as being potentially due to life. What followed was a wonderful demonstration of how science actually works. The claimed discovery was made and published; the data were released to the scientific community; scientists from around the world (including the original discoverers) reanalyzed the data and examined archival Venus data, or gathered new data, that might help confirm the findings. The scientific community then debated and discussed the findings and the data and came up with alternative explanations for both the identification of the phosphine signal, and possible non-life (abiotic) mechanisms for phosphine production. These alternative theories are being developed to make predictions that can ALSO be tested to see which competing theory has the most evidence, and so is more likely. The matter of whether there is phosphine, or life, in the Venus clouds is not yet settled, but now we have a much richer knowledge of the cases for and against such a conclusion. Directions! This week, I'd like for you to do a little research yourself and find a paper that is related to the phosphine-in-the-Venus-atmosphere debate. As you will see, not everyone thinks that the reported phosphine points to life (recall the Viking experiments on Mars); some can't even confirm the original detection, and some think it’s not phosphine at all! To narrow your search, I'd like for you to find an article that argues one of the four following possibilities (scientific hypotheses) and helps you answer some of the questions related to the hypothesis. 1. Phosphine was detected and is probably produced by biology. how was it detected? why are we certain it was detected? are there other observations that can be made to confirm that the PH3 is there? If so, what did they find? where in the Venus atmosphere was the PH3 detected? why would life be considered a good explanation for the phosphine? 2. The phosphine detection is not real, and there is nothing there in the Venus spectrum how did scientists try to reproduce the detection? What process were they using? why do scientists argue that the detection is not real? Is their argument convincing? 3. Phosphine was detected, but is probably abiotic in origin (i.e., not due to life). what other mechanism(s) in the Venus environment might produce phosphine? Are any of these plausible sources for phosphine? Why or why not? 4. Something was detected, but it’s not phosphine, and it’s something that is likely not due to life. If the detection is not due to phosphine, what else can it be? What evidence is there that the absorption is not due to phosphine? What did the initial discoverers do to try to rule out this other molecule? Why was it maybe not successful? What additional data are needed to help support this hypothesis? How should it be obtained? Is the alternative explanation more or less likely than life producing PH3 in the Venus clouds? Feel free to also think about how accurate the paper or article you are summarizing is, and what lessons can we take away from the Venus PH3 story about how really important science discoveries, like claims of extraterrestrial life detection, are reported. There's some background in the short video by Prof. Meadows, and you can use the usual websites for Reading Summaries (below) or search for related, reputable sources on the internet. There are a couple good ones, for example by National Geographic, Scientific American, and Nature News. NASA JPL: lots of Solar System mission news （https://www.jpl.nasa.gov/news） NASA Science: Good NASA news site （https://science.nasa.gov/science-news） SpaceNews: Space exploration news site（https://spacenews.com） Science Daily: Moon News: News on lunar science and exploration （https://www.sciencedaily.com/news/space_time/moon/） Wired Planetary Science: Cool news on all things planets （https://www.wired.com/tag/planetary-science/） Nature Planetary Science: some higher-level but really interesting planetary science articles. （https://www.nature.com/subjects/planetary-science） What to Submit 1. A summary of a paragraph or two (~10 sentences at a minimum) from an article that addresses one of the three points above, that also includes answers to the related bullet points. (The article must cite from the website I gave) 2. A minimum of two questions that the article left you wondering about. Occasionally your TA or Instructors will respond to these as well. You are welcome to post more than two questions. 3. A reference for the source (see http://www.wikihow.com/Cite-Sources for guidance) in case your TA or I need to refer to the original article. How to Cite Sources When you paraphrase or quote information from another source in a research paper, essay, or other written work, cite the original source of the information. Otherwise, your readers believe you are trying to pass this information off as your original thought. Proper citation adds credibility to your work and provides evidence to support any arguments you make. Your citations also give your readers the opportunity to further explore the topic of your work on their own
