Mars at perigee

Dominic Ford, Editor
From the Outer Planets feed


Objects: Mars

2255 apparition of Mars

11 Jul 2255 – Mars enters retrograde motion
10 Aug 2255 – Mars at opposition
13 Aug 2255 – Mars at perigee
10 Sep 2255 – Mars ends retrograde motion

Mars's orbit around the Sun will carry it to its closest point to the Earth – its perigee – passing within 0.38 AU of us.

The days around perigee represent the best time to observe Mars, since both its size and brightness in the night sky increase when it is close to us.

This effect is especially dramatic for Mars since it neighbours the Earth in the Solar System, orbiting a little further out from the Sun than us, at an average distance of 1.52 AU. As a result, it has the greatest variation of all the planets in its distance from the Earth, depending on whether the two planets are on opposite sides of the Sun, or passing next to one another in their respective orbits.

Mars reaches perigee at around the time when it passes the Earth in its orbit. At this time, the Sun, Earth and Mars lie in a straight line, with the Earth in the middle.

Consequently, Mars appears almost exactly opposite the Sun in the sky – a configuration called opposition, when Mars reaches its highest point in the sky at midnight and is visible for much of the night.

Every perigee of Mars is associated with a near-simultaneous opposition, but the two events typically occur a few days apart owing to the significant ellipticity of Mars's orbit.

On this occasion, Mars will attain a maximum angular diameter of 24.8 arcsec at closest approach, and a maximum brightness of magnitude -2.8 .

Observing Mars

Even at its closest approach to the Earth, it is never possible to distinguish Mars as more than a star-like point of light with the naked eye, though a simple pair of binoculars is sufficient to reveal it as a disk of light.

From South El Monte , it will be visible between 20:33 and 04:47. It will become accessible at around 20:33, when it rises to an altitude of 7° above your south-eastern horizon. It will reach its highest point in the sky at 00:40, 32° above your southern horizon. It will become inaccessible at around 04:47 when it sinks below 7° above your south-western horizon.

A chart of the path of Mars across the sky in 2255 can be found here, and a chart of its rising and setting times here.

The table below lists Mars' angular size and brightness at two-week intervals throughout its apparition:

Date Right ascension Declination Angular size Magnitude
01 Jun 225520h55m50s20°10'S13.8”-0.9
15 Jun 225521h16m10s19°36'S16.0”-1.3
29 Jun 225521h29m50s19°33'S18.5”-1.8
13 Jul 225521h34m30s20°13'S21.2”-2.2
27 Jul 225521h29m20s21°31'S23.6”-2.6
10 Aug 225521h16m10s22°58'S24.8”-2.8
24 Aug 225521h01m40s23°47'S24.2”-2.7
07 Sep 225520h53m40s23°35'S22.3”-2.3
21 Sep 225520h56m00s22°27'S19.7”-1.9
05 Oct 225521h08m10s20°36'S17.2”-1.6
19 Oct 225521h27m50s18°12'S15.0”-1.2

As Mars passes perigee, its position will be:

Object Right Ascension Declination Constellation Magnitude Angular Size
Mars 21h13m30s 23°10'S Capricornus -2.8 24.8"

The coordinates above are given in J2000.0.

The sky on 27 Dec 2025

The sky on 27 December 2025
Sunrise
06:54
Sunset
16:49
Twilight ends
18:19
Twilight begins
05:24


Waxing Gibbous

53%

7 days old

Planets
Rise Culm. Set
Mercury 05:55 10:51 15:46
Venus 06:47 11:41 16:35
Moon 11:37 17:57 00:26
Mars 07:12 12:05 16:59
Jupiter 17:54 01:00 08:07
Saturn 11:20 17:12 23:04
All times shown in PST.

Source

The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).

This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.

Related news

13 Aug 2255  –  Mars at perigee
10 Sep 2255  –  Mars ends retrograde motion
21 Sep 2257  –  Mars enters retrograde motion
18 Oct 2257  –  Mars at perigee

Image credit

© NASA/Hubble Space Telescope

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