add moon to calendar

1 files changed, 8 insertions, 0 deletions

diff --git a/CosmicCalendar.hs b/CosmicCalendar.hs
index b198328..de24889 100644
--- a/CosmicCalendar.hs
+++ b/CosmicCalendar.hs
@@ -521,6 +521,14 @@ Named Nyasasaurus parringtoni, the roughly 243-million-year-old fossils represen
     https://www.khanacademy.org/humanities/world-history/world-history-beginnings/origin-humans-early-societies/a/where-did-humans-come-from
     |],
 
+    CalendarEntry (4.4 & billionYearsAgo) Nothing
+    "Formation of the moon"
+    "A collision of the planet Theia with Earth creates the moon"
+    [text|
+    Astronomers think the collision between Earth and Theia happened at about 4.4 to 4.45 bya; about 0.1 billion years after the Solar System began to form.[15][16] In astronomical terms, the impact would have been of moderate velocity. Theia is thought to have struck Earth at an oblique angle when Earth was nearly fully formed. Computer simulations of this "late-impact" scenario suggest an initial impactor velocity at infinity below 4 kilometres per second (2.5 mi/s), increasing as it fell to over 9.3 km/s (5.8 mi/s) at impact, and an impact angle of about 45°.[17] However, oxygen isotope abundance in lunar rock suggests "vigorous mixing" of Theia and Earth, indicating a steep impact angle.[3][18] Theia's iron core would have sunk into the young Earth's core, and most of Theia's mantle accreted onto Earth's mantle. However, a significant portion of the mantle material from both Theia and Earth would have been ejected into orbit around Earth (if ejected with velocities between orbital velocity and escape velocity) or into individual orbits around the Sun (if ejected at higher velocities). Modelling[19] has hypothesised that material in orbit around Earth may have accreted to form the Moon in three consecutive phases; accreting first from the bodies initially present outside Earth's Roche limit, which acted to confine the inner disk material within the Roche limit. The inner disk slowly and viscously spread back out to Earth's Roche limit, pushing along outer bodies via resonant interactions. After several tens of years, the disk spread beyond the Roche limit, and started producing new objects that continued the growth of the Moon, until the inner disk was depleted in mass after several hundreds of years.
+    |]
+    "https://en.wikipedia.org/wiki/Giant-impact_hypothesis#Basic_model",
+
     CalendarEntry (600 & millionYearsAgo) Nothing
     "Multicellular life"
     ""