Dominic Ford, Editor
From the Outer Planets feed
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.
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 at around 19:09 (EDT) as the dusk sky fades, 16° above your south-eastern horizon. 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 00:47, when it sinks to 8° above your south-western horizon.
The exact position of Mars at the moment it passes perihelion will be:
|Object||Right Ascension||Declination||Constellation||Magnitude||Angular Size|
The coordinates above are given in J2000.0.
|The sky on 16 September 2018|
7 days old
All times shown in EDT.
The circumstances of this event were computed using the DE405 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.
|27 Jul 2018||– Mars at opposition|
|13 Oct 2020||– Mars at opposition|
|08 Dec 2022||– Mars at opposition|
|15 Jan 2025||– Mars at opposition|
© NASA/Hubble Space Telescope