2019 Planetary Motions

MERCURY: (highest point 27 degrees) (88 day orbit)

January 12: Aphelion (0.467 AU) (furthest point from the Sun)

January 30: Superior Conjunction (opposite the Sun from Earth & beginning apparition)

February 25: Perihelion (0.30 AU) (closest point to the Sun)

February 27: Greatest Eastern Elongation (18d E) (seen in the WEST as an Evening Star)

March 05: Stationary

March 15: Inferior Conjunction (directly between the Sun and the Earth)

March 27: Stationary

April 10: Aphelion (0.467 AU)

April 11: Greatest Western Elongation (27d W) (seen in the EAST as a Morning Star)

May 21: Superior Conjunction

May 24: Perihelion (0.30 AU)

June 23: Greatest Eastern Elongation (25d E)

July 07: Stationary

July 07: Aphelion (0.467 AU)

July 21: Inferior Conjunction

July 31: Stationary

August 09: Greatest Western Elongation (19d W)

August 20: Perihelion (0.31 AU)

September 04: Superior Conjunction

October 03: Aphelion (0.467 AU)

October 20: Greatest Eastern Elongation (23d E)

October 31: Stationary

November 11: Inferior Conjunction

November 16: Perihelion (0.30 AU)

November 20: Stationary

November 28: Greatest Western Elongation (20d W)

December 30: Aphelion (0.467 AU)







VENUS: (highest point 47 degrees) (225 day orbit)

January 06: Greatest Western Elongation (45 deg. W)

April 18: Aphelion (0.728 AU)

August 08: Perihelion (0.718 AU)

August 14: Superior Conjunction

November 28: Aphelion (0.728 AU)







EARTH: (Random Data): (365 day orbit)

January 03: Perihelion: Closest that the Earth gets to the Sun in its orbit (0.98 AU)

March 10: Spring Forward; Standard Time (ST) becomes Daylight Time (DT) (Daylight Savings begins on Sunday at 02:00)

March 20: Vernal (spring) Equinox (equal day/night)

March 20: Astronomical spring begins (Mar 20- June 20)

June 20: Astronomical summer begins (June 20- Sept 21)

June 20: Summer Solstice; longest day & highest “Solar Noon” (Northern Hemisphere)

July 04: Aphelion: Earth’s furthest point from the Sun in its orbit (1.017 AU)

September 22: Autumnal (fall) Equinox (equal day/night)

September 22: Astronomical fall begins (September 22 – December 20)

November 03: Fall Back. Daylight Time (DT) returns to Standard Time (ST) (Daylight Savings ends at Sunday at 02:00)

December 21: Astronomical winter begins (Dec 21 – Mar 19)

December 21: Winter Solstice; shortest day & lowest “Solar Noon” (Northern Hemisphere)


MARS: (687 day orbit)

August 26: Aphelion (1.66 AU)

September 02: Conjunction (opposite the Sun from the Earth)







VESTA (4 Vesta): (1,325 day or 3.63 year orbit)

November 12: Opposition (1.56 AU from Earth)






CERES (1 Ceres): (1,680 day or 4.6 year orbit)

May 28: Opposition (180 degrees)





JUPITER: (12 year orbit)

March 14: Western Quadrature (270 degrees)

April 10: Stationary

June 10: Opposition (180 degrees)

August 11: Stationary

September 08: Eastern Quadrature (90 degrees)

December 27: Conjunction (0 degrees)







SATURN: (29 year orbit)

January 02: Conjunction

April 10: Western Quadrature (270 degrees)

April 30: Stationary

July 09: Opposition (180 degrees)

September 18: Stationary

October 07: Eastern Quadrature (90 degrees)







URANUS: (84 year orbit)

January 07: Stationary

January 19: Eastern Quadrature (90 degrees)

April 22: Conjunction (0 degrees)

July 29: Western Quadrature (270 degrees)

August 12: Stationary

October 28: Opposition (180 degrees)








NEPTUNE: (165 year orbit)

March 07: Conjunction (0 degrees)

June 09: Western Quadrature (270 degrees)

June 22: Stationary

September 10: Opposition (180 degrees)

November 27: Stationary

December 08: Eastern Quadrature (90 degrees)







PLUTO: (248 year orbit)

January 11: Conjunction (0 degrees) (34.47 AU from Earth)

July 14: Opposition (180 degrees) (32.58 AU from Earth)







Perihelion: An objects closest approach to the Sun in its orbit.

Aphelion: An objects furthest point from the Sun in its orbit.

Perigee: An objects closest point to Earth in its orbit (Moon).

Apogee: An objects furthest point from Earth in its orbit (Moon).

Inferior Planet: Planets inside Earth’s orbit (Mercury & Venus).

Superior Planet: Planets outside Earth’s orbit (Mars, Jupiter, Saturn, Uranus & Neptune).

Terrestrial Planets: The four (4) rocky planets of the inner solar system (Mercury, Venus, Earth & Mars).

Jovian Planets: The four (4) gas giant planets of the outer solar system (Jupiter, Saturn, Uranus & Neptune).

Ice Giants: The extremely cold gas giants of the outer solar system (Uranus & Neptune).

Superior Conjunction: When an inferior (inner) planet is opposite the Sun from Earth (elongation of 0 degrees).

Inferior Conjunction: When an inferior (inner) planet is directly between the Sun & Earth (similar idea as the new moon) (elongation of 0 degrees).

Conjunction: When a superior (outer) planet is opposite the Sun from Earth (elongation of 0 degrees).

Opposition: When a superior (outer) planet is opposite the Earth from the Sun’s vantage point so on Earth we see it as a full disk. This is similar to when the Moon is full, its fully illuminated (elongation of 180 degrees).

Apparition: When a planet comes out from behind the Sun = superior conjunction (inner planets) or conjunction (outer planets) and begins to grow in apparent size as it heads toward inferior conjunction (inner planets) and opposition (outer planets).

Greatest Eastern Elongation: When an inferior planet comes out of superior conjunction it’s seen in the western sky after sunset. Its highest point is its greatest eastern elongation.

Greatest Western Elongation: When a planet comes out of inferior conjunction it’s seen in the eastern sky before sunrise. Its highest point on the sky is its greatest western elongation.

Eastern Quadrature: When superior (outer) planets are at an elongation of 90 degrees east of the Sun as viewed from Earth.

Western Quadrature: When superior (outer) planets are at an elongation of 90 degrees west of the Sun as viewed from Earth.

Stationary: When retrograde motion of an outer planet begins and ends & when an inferior planet reaches greatest Western or Eastern elongation. Its apparent motion on the sky becomes “stationary” momentarily.

Retrograde: When a superior (outer) planet appears to be moving backward on the night sky. This happens when Earth catches up to an outer planet and passes it on the inside.

Prograde: After the Earth has completed its pass of the superior (outer) planet its motion reassumes its normal direction of travel which for all planets is called prograde or direct motion.

Waxing: When the Moon or planet’s disk is growing in illumination from new up to full phase.

Waning: When the Moon or planet’s disk is decreasing in illumination from full to new.

Crescent: When the disk of the Moon or planet is less than 50% illuminated.

Gibbous: When the disk of the Moon or planet is more than 50% illuminated.

Solstice: (Summer & Winter) When Earth’s tilt is at its maximum twice annually creating the longest night in the winter and longest day in the summer.

Equinox: (Spring & Fall) When the Earth’s tilt is positioned twice annually to deliver equal day & night.

Cross Quarter: Markers mid-way between each of the Equinoxes & Solstices. All combined; the Equinoxes, Solstices and Cross Quarters create 8 markers throughout the year.

Celestial Phenomena: (Quadratures, oppositions, conjunctions etc.): http://eco.mtk.nao.ac.jp/cgi-bin/koyomi/cande/phenomena_en.cgi

British Astronomical Association (Computing section): http://britastro.org/computing/charts_asteroid.html

Major Solar System events in 2016: http://www.astropixels.com/ephemeris/astrocal/astrocal2016gmt.html

Planetary Aspects: http://cseligman.com/text/sky/aspects.htm

NMSU Planetary aspects page: http://astronomy.nmsu.edu/nicole/teaching/ASTR505/lectures/lecture08/slide09.html

Naked Eye Planets: http://www.nakedeyeplanets.com/

In-The-Sky: http://in-the-sky.org/newsindex.php?feed=outerplanets

TimeAndDate sunset/sunrise: http://www.timeanddate.com/worldclock/sunrise.html

USN sunrise/sunset: http://aa.usno.navy.mil/data/docs/RS_OneYear.php