Opposition

Mars at opposition in 2001, as seen by the Hubble Space Telescope. Image courtesy of NASA.
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 2021, computed from NASA's DE430 planetary ephemeris. To show events in other years, use the control below.
Objects at opposition in 2021
Date | Object | Declination |
Date | Object | Declination | |
21 Jan 2021 21:34 UTC | 15 Eunomia at opposition | 16°48'N | More information » |
24 Jan 2021 14:22 UTC | 14 Irene at opposition | 28°37'N | More information » |
02 Feb 2021 21:34 UTC | 18 Melpomene at opposition | 11°52'N | More information » |
22 Feb 2021 16:46 UTC | 29 Amphitrite at opposition | 13°40'N | More information » |
04 Mar 2021 23:58 UTC | 4 Vesta at opposition | 15°57'N | More information » |
27 Mar 2021 14:42 UTC | 136472 Makemake at opposition | 23°16'N | More information » |
05 Apr 2021 04:46 UTC | 9 Metis at opposition | 0°57'N | More information » |
18 Apr 2021 00:03 UTC | 136108 Haumea at opposition | 16°05'N | More information » |
04 Jun 2021 07:10 UTC | 63 Ausonia at opposition | 33°21'S | More information » |
18 Jul 2021 06:20 UTC | 134340 Pluto at opposition | 22°34'S | More information » |
18 Jul 2021 21:34 UTC | 6 Hebe at opposition | 10°35'S | More information » |
30 Jul 2021 19:10 UTC | 12 Victoria at opposition | 1°10'S | More information » |
02 Aug 2021 06:01 UTC | Saturn at opposition | 18°31'S | More information » |
12 Aug 2021 21:34 UTC | 349 Dembowska at opposition | 26°27'S | More information » |
19 Aug 2021 19:10 UTC | 43 Ariadne at opposition | 6°32'S | More information » |
20 Aug 2021 00:16 UTC | Jupiter at opposition | 13°38'S | More information » |
24 Aug 2021 14:22 UTC | 89 Julia at opposition | 0°15'S | More information » |
11 Sep 2021 19:10 UTC | 2 Pallas at opposition | 0°16'S | More information » |
14 Sep 2021 09:06 UTC | Neptune at opposition | 4°27'S | More information » |
02 Oct 2021 02:22 UTC | 40 Harmonia at opposition | 3°43'S | More information » |
17 Oct 2021 16:32 UTC | 136199 Eris at opposition | 1°19'S | More information » |
04 Nov 2021 23:43 UTC | Uranus at opposition | 15°10'N | More information » |
27 Nov 2021 07:00 UTC | 1 Ceres at opposition | 16°44'N | More information » |
10 Dec 2021 19:10 UTC | 44 Nysa at opposition | 17°24'N | More information » |