#4 favourite sky-rocks

(Paper crunch + resurgence of home internot has made things complicated! I am currently sat in a restaurant and putting things together.)

• Pallasites! They're very pretty, and they are (probably) what happens when you've got something meteorite-ish big enough that it starts differentiating into a metallic core (whence iron meteorites) and silicate body (hence a subset of stony meteorites) and then gets smashed up -- with pallasites being what you get from the core-mantle-boundary equivalent! So you've got the translucent yellow-green olivine (which is the major constituent of the silicate mantle and is in gem quality called epidote) embedded in iron-nickel alloy and it's pretty.
  
• The Iron Meteor I Found Under My Desk. It is about the age of the solar system, as you can tell from the scale of the Widmanstätten patterns.
  
• MARTIAN METEORS, okay. Very roughly - and I'm not looking up references for this while awesome ex-housemate C and D and K Xeno's paradox cheese-bread at Kyrgyz Kazakh House - we knew Martian meteors were from Mars before we had ever made it to Mars because, right, meteors frequently contain entrapped gases from their atmosphere-of-origin. Now the precise isotopic composition of that atmospheric gas - how much ¹H to ²H, or (more helpfully in this particular example) the ratio of ¹⁵N to ¹⁴N - lets you work out the required gravity field in order for the right amount of the lighter isotope to escape the gravity well from the top of the atmosphere. And it turns out that you calculate this out and discover that Martian meteorites must have come from a Mars-sized body, and then we sent brave space robots to Mars, and the atmospheric compositions matched (and so did the rock compositions insofar as we could tell), and basically it's all really cool.

Special bonus mention to the Moon, which is the only space rock I've actually published anything on; I continue very excited about lunar formation nonsense, and was delighted by a recent review paper on the lunar dynamo written by a friend of a friend. Lunar differentiation is a topic on which I can be very excitable with respect to Canadian analogues so!

#5 Geology near my home or lab

Honestly? I live in a sedimentary pseudo-basin, so to me the most exciting things are the building stones. Which -- don't get me wrong! There's some lovely ones! There's a garnetiferous marble used to face this one building, which has streaks of tiny garnets pressed into waves and curls and it's great. There are also My Favourite Kerbstones, full of great big semi-aligned plagioclase laths; and lots of nice labradorite granites.

Much more interesting is the coast around the Mouldering Ancestral Pile: the beach a five minute walk away (Polurrian) features an outcropping of the Lizard Boundary Fault - the join between continental and oceanic crust. And then there's the Lizard complex as a whole, wherein what-used-to-be-the-mantle is actually exposed at the surface - over a few miles of coast you can actually walk from the base of old oceanic crust up to the surface, through gabbroic cumulates and sheeted dykes and pillow basalts; you can literally stand on an exposure of the Moho-that-was, the boundary between crust and mantle, and it's really cool. SO: for these purposes, Cornwall is home much more than London is. ;)

#7 Traditional pre-Christmas practices

Okay, so this one is (~surprise~) a bit fraught for me, because a lot of my culture-of-origin identity is very bound up with Mitteleuropäischer expressions of Catholicism, so I end up feeling a lot more adrift with the whole atheist thing than is wholly comfortable.

All of which said, my traditional stuff is:

• you make a wreath from misc evergreen from your garden (or, in the more specific sense, misc evergreen you've nicked from a Cambridge college's gardens); you place your Advent candle in the middle of it, and add a candle round the edge for each Sunday of Advent in the appropriate colors as they happen. Advent is very much a time of preparation & reflection: to think about what one has done and what one has failed to do, and all that.
  
• the 6th of December, Heiliger Nikolaus: on the evening of the 5th, you polish your shoes and leave them lined up neatly beneath a window, and awake to find (if you've been good!) that Nikolaus has been by in the night and filled them with goodies, traditionally nuts & clementines & chocolate coins. (My mother normally manages to source chocolate Schilling - when that was relevant - and these days usually gets her hands on chocolate Euro. Me, I noticed that M&S were selling chocolate brussels sprouts and thought it would be worth it for the laugh). If you have not then instead the Krampus chases you with switches...
  
• on the other side of the family, my father gets Very Definite about making mince pies in the week running up to Christmas; he normally makes a round twelve dozen, as I recall, glazed with water+sugar (because my baby brother is lactose intolerant). He makes the pastry - standard unsweetened shortcrust - but usually buys in the mincemeat; I am still working through the batch I made a couple of years ago, during The Winter Of My Discontent.
  
• (My mother makes fruitcake and steamed puddings a little while in advance; she makes the marzipan and royal icing, and in deference to my tastes leaves the glacé cherries out.)
  
• Otherwise, preparation waits until Christmas Eve: present wrapping and bringing in (and decorating) the tree (which lives in the garden), and setting up the crib, and so on. (The Wise Men then advance from the far side of the tableau to the stable over the course of the twelve days.) We listen to the King's Carol Service because my father, bizarrely, insists; my mother staples the Christmas cards to lengths of ribbon and hangs them from the walls; we get out the Strohsterne etc.

... and then we are into The Day Itself, which involves Church and arguments and I am kiiiiiind of intending to run back to London to spend the day with a bunch of heathens this year before heading back on Boxing Day.