Jupiter's orbit around the Sun will carry it to its closest point to the Earth – its perigee – passing within 4.01 AU of us.
Jupiter reaches perigee at around the time when it passes the Earth in its orbit. At this time, the Sun, Earth and Jupiter lie in a straight line, with the Earth in the middle.
Consequently, Jupiter appears almost exactly opposite the Sun in the sky – a configuration called opposition, when Jupiter reaches its highest point in the sky at midnight and is visible for much of the night.
Every perigee of Jupiter is associated with a near-simultaneous opposition.
On this occasion, Jupiter will attain a maximum angular diameter of 48.0 arcsec at closest approach, and a maximum brightness of magnitude -2.9 .
Observing Jupiter
Even at its closest approach to the Earth, it is never possible to distinguish Jupiter 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 Cambridge , it will be visible between 20:25 and 05:09. It will become accessible at around 20:25, when it rises to an altitude of 7° above your south-eastern horizon. It will reach its highest point in the sky at 00:47, 33° above your southern horizon. It will become inaccessible at around 05:09 when it sinks below 7° above your south-western horizon.
A chart of the path of Jupiter across the sky in 2021 can be found here, and a chart of its rising and setting times here.
The position of Jupiter at the moment it passes perigee will be:
| Object | Right Ascension | Declination | Constellation | Magnitude | Angular Size |
| Jupiter | 21h58m00s | 13°39'S | Capricornus | -2.9 | 48.0" |
The coordinates above are given in J2000.0.
The sky on 20 Aug 2021
| The sky on 20 August 2021 | ||||||||||||||||||||||||||||||||||
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96% 12 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
| 19 Aug 2021 | – Jupiter at opposition |
| 18 Oct 2021 | – Jupiter ends retrograde motion |
| 28 Jul 2022 | – Jupiter enters retrograde motion |
| 26 Sep 2022 | – Jupiter at opposition |
Image credit
© NASA/Cassini