Characteristics

Mean apparent diameter 31´ 59´´,26
Radius 696 000 km = 109,1 of Earth's radius
Surface 11 908 of Earth's surface
Volume 1 299 410 of Earth's volume
Mass 332 946 of Earth's mass
Mean density 0,255 of Earth's mean density = 1,408 of water's mean density
Acceleration due to gravity at the equator 274 m/s² = 28 of Earth's gravity
Duration of sidereal spots rotation (latitude 16°) 25,38 days
Mean duration of one sunspots cycle 10,9 years
Solar constant 1366 Wm-2
Equatorial horizontal parallax at mean distance 8´´,794143
Average distance to Earth 149,6 x 10⁶ km
Inclinaison of Sun equator to ecliptic 7° 52´,3
longitude of Sun equator ascending node to ecliptic 76° 00´ ,7
Mean obliquity of the ecliptic, at 1st january 2018 23° 26´ 13´´ ,02
True obliquity of the ecliptic, at 1st january 2018 23° 26´ 05´´ ,66
True obliquity of the ecliptic, at 1st july 2018 23° 26´ 06´´ ,66
True obliquity of the ecliptic, at 31 december 2018 23° 26´ 07´´ ,86
Value of the general precession (in Julian century) 5029´´ ,2051
Nutation constant (epoch 2000) 9´´ ,2052
Aberration constant (epoch 2000) 20´´ ,49552
Mean longitude of the perigee the 1st january 2018 at 0h (Universal Time; reported on the equinox through the date) 283° 14´ 48´´ ,6
Mean motion of the perigee (by year) 61´´ ,89
Longitude of ascending node of the invariable plane on the ecliptic of 1850 106° 14´ 06´´
Inclination of the invariable plane on the ecliptic of 1850 1° 35´ 19´´
Sidereal year 365,256 362 days = 365d 06h 09m 09s,6
Tropical year 365,242 188 days = 365d 05h 48m 45s,1
Anomalistic Year 365,259 636 days = 365d 06h 13m 52s,5

Beginning of the Astronomical seasons

Spring 20 march at 16h 15m
Summer 21 june at 10h 07m
Autumn 23 september at 1h 54m
Winter 21 december at 22h 23m

Synodic solar rotation

NumberBeginning of rotation
2200 2018 Janvier -- Januari 27,28
2201 Février -- Februari 23,62
2202 Mars -- Maart 22,94
2203 Avril -- April 19,22
2204 Mai -- Mei 16,46
2205 Juin -- Juni 12,66
2206 Juillet -- Juli 9,86
2207 Août -- Augustus 6,07
2208 Septembre -- September 2,31
2209 Septembre -- September 29,58
2210 Octobre -- Oktober 26,87
2211 Novembre -- November 23,17
2212 Décembre -- December 20,49


Terre au périhélie: 3 janvier à 6h. | Aarde in het perihelium: 3 januari om 6h.
Terre à l'aphélie: 6 juillet à 17h. | Aarde in het aphelium: 6 juli om 17h.