Mars's 687-day orbit around the Sun will carry it to its closest point to the Sun – its perihelion – at a distance of 1.38 AU.
Unlike most of the planets, which follow almost exactly circular orbits around the Sun which only vary in their distance from the Sun by a few percent, Mars has a significantly elliptical orbit. Its distance from the Sun varies between 1.38 AU and 1.67 AU – a variation of over 20% – meaning that it receives 31% less heat and light from the Sun at aphelion as compared to perihelion.
Finding Mars
Mars's distance from the Sun doesn't affect its appearance. From Cambridge, at the moment of perihelion it will be visible in the evening sky, becoming accessible around 19:09 (EST), 16° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 21:17, 23° above your southern horizon. It will continue to be observable until around 00:43, when it sinks below 7° above your south-western horizon.
A chart of the path of Mars across the sky in 2018 can be found here, and a chart of its rising and setting times here.
The position of Mars at the moment it passes perihelion will be:
Object | Right Ascension | Declination | Constellation | Magnitude | Angular Size |
Mars | 20h17m10s | 24°34'S | Capricornus | -1.7 | 18.1" |
The coordinates above are given in J2000.0.
The sky on 16 Sep 2018
The sky on 16 September 2018 | ||||||||||||||||||||||||||||||||||
50% 7 days old |
All times shown in EDT.
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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
27 Aug 2018 | – Mars ends retrograde motion |
23 Aug 2020 | – Mars 2020: a great chance to see the red planet |
09 Sep 2020 | – Mars enters retrograde motion |
06 Oct 2020 | – Mars at perigee |
Image credit
© NASA/Hubble Space Telescope