Since the size and brightness of Mars in the night sky both increase when it is close to us, the days around its perigee represent the best time to observe it.
This effect is especially pronounced 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.
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 San Diego, it will be visible in the morning sky, becoming accessible around 17:54, when it reaches an altitude of 7° above your north-eastern horizon. It will then reach its highest point in the sky at 00:21, 82° above your southern horizon. It will be lost to dawn twilight around 06:32, 10° above your western horizon.
The exact position of Mars at the moment it passes perigee will be:
|Object||Right Ascension||Declination||Constellation||Magnitude||Angular Size|
The coordinates above are given in J2000.0.
|The sky on 12 January 2025|
13 days old
All times shown in PST.
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.
|12 Jan 2025||– Mars at perigee|
|15 Jan 2025||– Mars at opposition|
|19 Feb 2027||– Mars at opposition|
|19 Feb 2027||– Mars at perigee|
© NASA/Hubble Space Telescope