Reading: Dauphas and Chaussidon (2011)
1. Fig. 2 shows schematic 26Mg/24Mg vs. 27Al/24Mg diagrams for the 26Al - 26Mg short-lived chronometer. The top panel shows the formation of object 0, the bottom the formation of object 1. Explain what two things vary between object 0 and 1 and how this relates to a difference in formation time.
2. For Fig. 3, create a table summarizing 26Al data and astrophysical settings for the objects dated in panels a, b, c, d. Your table should have the first column identifying the object, a second column identifying the corresponding initial 26Al/27Al value, and a third column that identifies the coresponding setting (e.g., molecular cloud, protostar YSO with disk, pre-main sequence YSO with disk).
3. How were short-lived nuclides injected into the solar nebula and what potential problems for these have been identified? HINT: There are two different types of injecting sources, one of which has 3 variants.
4. Create a list of specific short-lived nuclides that can be created by irradiation close to the T-Tauri sun, stating for each nuclide whether the case for irradiation is discussed as strong (S), not definitive (ND), or weak (W), and in which type of object the anomalies are identified.
5. What is the meter size barrier?
6. According to the data summarized in this paper for short-lived chronometry, when did chondrules form relative to CAIs, iron meteorites, and basaltic achondites (eucrites, angrites)?
7. Explain how 182W/183W variations can be used to date core formation on various objects. What age for "instantaneous core formation" is inferred for Mars? For Earth? What is the age of the Moon?