|The Earth and Its Moon|
In General, Parts and Properties
* Parameters: a = 150 Mkm = 1 au; REarth = 6378 km, Prev = 365 d, Prot = 1.00 d; MEarth = 5.972245 ± .000082 × 1024 kg (2001 value).
* Tides: There are terrestrial as well as water tides (the height of Geneva varies by about 25 cm).
* Vibrations: 1998, several modes in the MHz range have been seen, attributed to atmospheric turbulence.
* Electric field: Near the surface is it downward-directed and has a magnitude of 100-200 V/m; The corresponding charges leak because of atmospheric conductivity on a time scale of about 300 s, but the global circuit is charged by thunderstorms (cloud-to-ground flashes).
* Interior and tectonics: Mantle convection results in plate tectonics and in a shift in the relative orientation of the Earth's solid surface and its rotational axis.
* Energy production: About 50% of the heat given off by the Earth is generated by the radioactive decay of elements such as uranium and thorium, and their decay products.
@ Orbit and general properties: Iorio AJ(11)-a1102 [anomalous secular increase in the astronomical unit]; Schreiber et al PRL(11) [detecting wobbles in the Earth's rotation]; Acedo ASR(13)-a1401 [secular increase of the Astronomical Unit and anomalous post-Newtonian terms]; Li & Batygin ApJ(14)-a1409 [evolution of the Earth's obliquity]; Sigismondi a1412 [first measurements of Earth's obliquity, in 1701]; Pellizza et al AJP(15)dec [demonstration of the conservation of the orbital angular momentum]; > s.a. gravitational constant.
@ Interior and tectonics: ThSc(90)sep, p23; Lay et al PT(90)oct; Taylor & McLennan SA(96)jan [continental crust]; issue PW(96)may; Jain et al APP(99)hp, Ralston et al ap/99-proc [solar tomography]; Gurnis SA(01)mar [tectonics]; Kanamori & Brodsky PT(01)jun [physics of earthquakes]; Alfè et al CP(07) [core]; Argus pw(07)dec [location of center]; Shiltsev PRL(10) + news focus(10)jun + pw(10)jun [random ground movement]; news pw(11)jul [energy production]; news pw(12)nov [oscillatory true polar wander]; Umino et al PT(13)aug [drilling to the mantle]; Buffett PT(13)nov [the inner core].
@ Magnetic field: Jacobs CP(95); Fuller et al AS(96) [reversal]; Harrison AJP(01)may [RL]; Geissman pw(04)apr [reversal]; Glatzmaier & Olson SA(05)apr [geodynamo]; Stefani et al MHD(06)phy [reversal, model]; Cruice 07 [Earth's magnetic field and life]; Love PT(08)feb [monitoring]; news ns(10)sep [fast reversals]; news pw(12)nov [Cluster mission findings]; Olson PT(13)nov [insights into the geodynamo]; news sd(14)jul [how are electrons accelerated in the Van Allen belts?].
@ Auroras: Jago 01 [Birkeland, r pw(01)sep]; news pw(08)may [polarization].
Atmosphere > s.a. sound [acoustic gravity waves];
* Electricity: The charge distribution in thunderstorms presents usually at least 4 regions of alternating sign (ρ ≈ nC/m3), but little is known about the horizontal E (02.1997; & T Marshall, M Stolzenburg).
* Lightning: The mechanism is not the type of breakdown we normally observe, because the intrinsically occurring electric fields are far too small; Instead, it seems to be triggered by runaway breakdown started by cosmic rays and their many charged secondaries; The leader is formed by high-energy, relativistic electrons, which feel a smaller drag force (dE/dx) than slow-moving ones and form a conducting channel to the ground (they also increase the electric field, and emit X-rays and gamma rays), along which a current then flows; The current causes the visible lightning, and heats the air to many thousands of K, which then expands and causes the thunder; 2014, Role of solar wind?
* Clouds: Research suggests that they form when interstellar cosmic rays collide with water molecules in our atmosphere.
@ General references: Peixoto & Oort 92; Dauphas Icarus(03)ap [origin].
@ Lightning: Lomonosov 1753-a1709; Diels et al SA(97)aug [control with lasers]; Mende et al SA(97)aug [above thunderstorms]; MacGorman & Rust 98 [r PT(99)may]; Rakov & Uman 03 [r PT(04)dec]; Gurevich & Zybin PT(05)may [cosmic rays and runaway breakdown]; Dwyer & Uman PRP(14); news nat(14)may [and solar wind].
@ Weather: Koscielny-Bunde et al PRL(98) [t correlations]; Turner PRP(98) [ball lightning]; Lubchenco & Karl PT(12)mar [predicting and managing].
@ Climate change: Weart PT(03)aug; Richter 10 [r PT(11)jan]; Somerville & Hassol PT(11)oct; blog pt(11)oct; Carbone et al a1701 [Foscarini 1615].
@ Atmospheric optics: Adam PRP(02) [rainbows & glories]; Hardwick pw(04)feb; Fantz CP(04) [rev].
@ Electric field: Bering et al PT(98)oct [global electric circuit]; Schellart et al PRL(15) + news nyt(15)apr [radio emission from cosmic-ray air showers in thunderstorms]; news sn(19)feb, Phys(19)mar [probed with muons, electric potential of 1.3 GV].
@ Related topics: Griffin et al AS(02) [global transport of dust]; Vollmer AJP(03)oct [simple thickness estimate]; news sr(05)aug [origin of O dominance]; news SciNow(09)aug [clouds and cosmic rays]; news pw(10)apr, Chilingarian et al PRD(11) [thunderstorms as particle accelerators]; Stevens & Bony PT(13)jun [water]; news pt(15)jun [imaging of plasma ducts]; > s.a. cosmic rays; gamma-ray astronomy [terrestrial gamma-ray flashes].
Special Topics > s.a. critical phenomena;
interstellar matter [dust]; light [rainbows].
* Formation: Earth accreted and segregated a metal core by a succession of large impacts before the solar system was 100 million years old.
* Artificial satellites: The idea of geosynchronous satellites was first published by A C Clarke in the 1950s; They orbit 35,900 km above sea level, ≈ 6.5 REarth; The Shuttle and others orbit at 500 km, with a period of 90 min.
@ Formation, early history: SA(93)jan, p90 [earliest history]; Ahrens PT(94)aug; Baez pw(09)aug [bombardment]; Lenton & Watson 11 [r CP(11)#6]; Wood PT(11)dec [overview]; Feulner RoG(12)-a1204 [the "faint young Sun problem"]; Hazen 12; Marty EPSL(12)-a1405 [origins and concentrations of water, C, N and noble gases].
@ And space: Burch SA(01)apr [space storms]; Pustilnik & Yom Din SolPh(04)ap-conf [space weather and prices]; Baker & Lanzerotti AJP(16)mar [RL]; > s.a. solar system [NEOs].
@ Orbit. motion: Mohazzabi & Luecke AJP(03)jul [eccentricity not due to asteroid collision]; Miura et al PASJ(09)-a0905, Bel a1003 [secular increase of AU]; Sigismondi a1107-proc [measuring the Earth-Sun distance]; McCabe JCAP(14) [velocity in galactic coordinates]; Oostra PT(15)dec [orbital eccentricity].
@ Specific regions: Shepherd pw(06)may [Antarctica].
@ Other topics: Kirshner SA(94)oct [elements]; Dalziel SA(95)jan [before Pangaea]; Johnson SA(98)aug [space debris]; Bourda & Capitaine A&A(04)-a0711 [precession, nutation, etc]; Genda & Ikoma Icarus(08)-a0709 [origin of oceans]; Tremaine & Yavetz AJP(14)-a1309 [why artificial satellites stay up].
The Moon > s.a. anthropic principle.
* Motion: It recedes from the Earth at 3.8 cm/yr, and slows Earth's rotation.
* Formation: The Moon probably formed when a Mars-sized protoplanet (Theia) smashed into the Earth, at least 4.5 Gyr ago (50 to 100 million years after the beginning of planet formation), ejecting matter into orbit and lengthening our day to its present value of 24 hours; At most two-thirds of the Moon is impactor material.
* Composition: Analysis of hundreds of kg of lunar rock returned by the Apollo missions shows that its bulk chemical composition is largely the same as that of Earth's mantle but for a striking depletion of relatively volatile elements, such as potassium and other alkali metals (due to post-impact processes).
* Missions: 1996, Lunar Prospector for minerals scheduled for launch in 1997.
@ General references: Arbab AGGH(04)ap/01 [evolution of Earth-Moon system]; Spudis SA(03)dec [new findings]; Mohit AS(08)may [near vs far side]; news bbc(11)jun [simulations show large moons could be common].
@ Orbital eccentricity: Iorio MNRAS(11)-a1102, a1105-proc, Gal(14)-a1404 [anomalous secular increase]; Oostra TPT(14) [in introductory astronomy].
@ Observation: North 00; Steele 12 [history, 1691–1757]; Krisciunas AsJP-a1311 [distance and motion, ancient and modern observations]; Pellizza et al AJP(14)apr, Oostra AJP(14)apr [distance and motion, simple measurements].
@ Formation / origin: Taylor AS(87); Drake Nat(90)sep; Münker et al Sci(03)jul + pw(03)jul; Mackenzie 03 [r PT(04)may]; Belbruno & Gott AJ(05)ap/04; Valley SA(05)oct [early evolution]; Pahlevan & Stevenson EPSL(07)-a1012 [collision aftermath and mixing]; de Meijer et al JCG(12)-a1001 [alternative proposal]; news sn(11)oct; news pw(12)mar [further doubts cast on models]; Reufer et al Icarus(12)-a1207 [hit-and-run scenario]; news guard(12)dec, ns(13)aug [gravity map and scars]; news ls(13)sep [from Venus?]; Wise PT(14)jan, Gupta a1402 [alternative models]; Stevenson PT(14)nov; Dvorak et al a1506/MNRAS [probability of formation by collision]; Barr JGR(16)-a1608; Denevi PT(17)jun; > s.a. Theia.
@ Related topics: Hershenson ed-89 [Moon illusion]; Vondrak & Crider AS(03) [polar ice]; Hawke et al Icarus(04) [crater rays]; Lester ap/07-proc [as a telescope site]; news ng(12)feb [relatively recent tectonic activity]; Crotts AR(11)-a1205, AR(12)-a1205, AR(12)-a1205 [water]; Crawford et al PSS(12)-a1206 [the case for resuming lunar surface exploration]; Murphy RPP(13)-a1309 [lunar laser ranging]; Crawford PPG-a1410 [resources, rev].
– journals – comments
– other sites – acknowledgements
send feedback and suggestions to bombelli at olemiss.edu – modified 23 mar 2019