Opposition

by Dominic Ford, Editor
Opposition

Mars at opposition in 2001, as seen by the Hubble Space Telescope

An astronomical body is said to be at opposition when it makes its closest approach to the point directly opposite to the Sun in the night sky.

This means that the object will appear highest in the sky at around midnight, local time, and will be above the horizon for much of the night.

For objects which orbit further out in the Solar System than the Earth – almost all bodies other than Mercury and Venus – this configuration happens when the Solar System is aligned such that the object lies in a straight line with the Earth and the Sun, the Earth being in the middle.

Consequently, this is also the time when the object makes its closest approach to the Earth, making it appear at its largest and brightest in the night sky.

List of oppositions

The table below lists the dates when objects are at opposition in 2018, computed from NASA's DE405 planetary ephemeris. To show dates in other years, use the dropdown control.

List objects at opposition in year

Date Object Declination
Date Object Declination
03 Jan 2018 00:00 UTC8 Flora at opposition21°07'NMore information »
31 Jan 2018 07:11 UTC1 Ceres at opposition30°06'NMore information »
31 Jan 2018 16:28 UTC1 Ceres at opposition30°09'NMore information »
24 Mar 2018 14:04 UTC136472 Makemake at opposition24°48'NMore information »
14 Apr 2018 17:58 UTC136108 Haumea at opposition17°04'NMore information »
08 May 2018 19:11 UTC15 Eunomia at opposition32°05'SMore information »
09 May 2018 00:28 UTCJupiter at opposition16°00'SMore information »
15 Jun 2018 12:00 UTC29 Amphitrite at opposition32°55'SMore information »
16 Jun 2018 16:48 UTC9 Metis at opposition25°53'SMore information »
20 Jun 2018 00:00 UTC4 Vesta at opposition19°49'SMore information »
27 Jun 2018 13:15 UTCSaturn at opposition22°28'SMore information »
12 Jul 2018 09:42 UTC134340 Pluto at opposition21°49'SMore information »
20 Jul 2018 02:24 UTC88 Thisbe at opposition17°29'SMore information »
27 Jul 2018 05:07 UTCMars at opposition25°33'SMore information »
05 Sep 2018 16:48 UTC27 Euterpe at opposition9°03'SMore information »
07 Sep 2018 18:13 UTCNeptune at opposition6°54'SMore information »
18 Sep 2018 19:11 UTC30 Urania at opposition0°58'NMore information »
16 Oct 2018 22:58 UTC136199 Eris at opposition2°13'SMore information »
24 Oct 2018 00:33 UTCUranus at opposition11°02'NMore information »
16 Nov 2018 12:00 UTC3 Juno at opposition3°26'SMore information »
08 Dec 2018 19:11 UTC40 Harmonia at opposition20°24'NMore information »
17 Dec 2018 00:00 UTC433 Eros at opposition60°03'NMore information »
29 Dec 2018 09:35 UTC6 Hebe at opposition5°27'NMore information »

Ashburn

Latitude:
Longitude:
Timezone:

39.04°N
77.49°W
EDT

Color scheme