This morning bright Jupiter is to the upper right of Saturn and Mars. The Red Planet 1.2° to the lower right of the Ringed Wonder. Jupiter is 6.4° to the upper right of Saturn. In the starfield, Jupiter is 1.7° to the lower right of 56 Sagittarii.
For more about tomorrow’s conjunction, click here.
The three Bright Outer Planets – Jupiter, Saturn, and Mars – are found in the southeastern pre-sunrise sky throughout April 2020. Jupiter continues its approach to Saturn for the Great Conjunction of December 21, 2020.
For more about the Great Conjunction of Jupiter and Saturn, click here.
Click here for our detailed notes for the planets during April 2020.
The three worlds look like bright stars to our eyes. Jupiter is the brightest of the planetary trio. Saturn and Mars are nearby, to Jupiter’s lower left.
One hour before sunrise, bright Jupiter is nearly 19° up in the southeast. Saturn and Mars are one day past their conjunction. Mars is 1.0° to the lower left of Saturn and the Ringed Wonder is 6.2° to the lower left of Jupiter. The planetary trio spans 6.7°. Watch the span grow about 0.6° each day. To view the trio this close, you’ll have to wait 20 years. By month’s end the BOPs span over 24° as Mars marches eastward.
As Mars moves away from Saturn, Jupiter slowly closes the gap to Saturn for the once-in-a-generation Great Conjunction later this year. Watch carefully, as Jupiter inches eastward in its orbit faster than Saturn.
If you have a binocular an a star chart, watch Jupiter slowly move past a dimmer star. Jupiter 1.6° to the lower right of 56 Sagittarii (56 Sgr, m = 4.8). Watch Jupiter sneak past the star during the next several days. Use a binocular to see Jupiter in the starfield.
Each morning, Mars appears farther east than the previous day, by an amount equal to the apparent size of the moon. By April 9, the Bright Outer Planets appear equally spaced in the southeastern pre-dawn sky. One hour before sunrise, Jupiter is over 20° up in the south-southeast. Jupiter is the brightest. The other two planets are diagonally to Jupiter’s lower left. Saturn is 5.7° from Jupiter and Mars.
With a binocular and a star chart, find the background stars near Jupiter and Mars. Jupiter is 1.5° below 56 Sagittarii. Mars is 1.9° to the lower left of Omicron Sagittarii and 1.8° to the lower right of Upsilon Capricorni.
On April 15, the moon joins Jupiter, Saturn, and Mars. The thick crescent moon (22.0 days past its New Moon phase, 45% illuminated) is 3.3° below Saturn, 20° up in the southeast. This morning bright Jupiter is 5.5° to the upper right of Saturn and 14.9° to the upper right of Mars.
With your binocular and star chart find Jupiter and Mars in the starfield. Jupiter is 1.8° to the lower left of 56 Sagittarii, while Mars is 3.3° to the right of Theta Capricorni.
By month’s end, Mars leaves the two giant planets. One hour before sunrise, Jupiter – over 24° up in the south-southeast – is 4.9° to the upper right of Saturn. The Ringed Wonder is 19.4° to the upper right of Mars. The Bright Outer Planets span 24.3° along the ecliptic.
In the starfield, Jupiter is 2.3° to the lower left of 56 Sagittarii. Mars is 1.2° to the upper right of Gamma Capricorni.
This morning Jupiter, Saturn, and Mars – the Bright Outer Planets – stretch across the southeastern sky. The gap between Saturn and Mars is 17.9°. Mars is 9.4° to the upper right of Jupiter. Jupiter is 8.5° to the upper right of Saturn
In the starfield Jupiter and Mars are in front of the stars of Sagittarius. Jupiter is 3.7° to the lower left of Phi Sagittarii. Mars is 3.8° to the upper right of Nunki and 4.1° to the left of Kaus Borealis.
Mars marches eastward compared to the starry background. It catches and passes Jupiter on March 20 and Saturn, March 31.
In two mornings, March 4, Jupiter is nearly midway between Mars and Saturn as Mars closes the gaps on the planetary pair.
The morning planet parade is taking shape as Saturn becomes visible in the southeast after its solar conjunction. Three bright morning planets are visible in the southeast before sunrise. During the next month, watch Mars approach and pass both planets. Each morning Mars is noticeably closer to Jupiter. Mars passes Jupiter on March 20 and Saturn, March 31. The three planets have not appeared this close in the sky for about 20 years.
On the next clear morning, look to the southeast, bright Jupiter is low in the sky. It is the brightest “star” in that part of the sky – only the sun, moon, and Venus are brighter. Dimmer Mars is to Jupiter’s upper right. As with our photograph, Saturn may be hiding near a neighbor’s house or tree, to the lower left of Jupiter.
In the sky, without a telescope, these worlds appear as bright stars. As they move through their orbits, they seem to move relative to the constellations. Historically, they were called the “wandering stars” — the “planets.” To our ancestors there were seven known wanderers — sun, moon, Mercury, Venus, Mars, Jupiter, and Saturn. They were so important that the days of the week were named for them.
After the invention of the telescope, these “stars” were first seen as separate worlds.
The 2020 Great Conjunction of Jupiter and Saturn is the closest conjunction of these giant planets since the conjunction of them in 1623.
Was this conjunction observed?
The Jupiter – Saturn conjunction of 1623 occurred in the wake of the invention of the telescope, so observing was in its infancy; yet, the sky was full of planetary activity. A partial lunar eclipse (April 15, 1623) was visible throughout the Americas and in Central Europe, where the moon was setting as the eclipse reached its 90% magnitude. Venus passed Jupiter and Saturn in late June and Mercury passed the planetary pair less than two weeks later, when the planets were about 22° east of the sun. With the inner planets in the vicinity of the impending Great Conjunction and Mars reaching opposition (July 4, 1623), surely sky watchers were observing the planets’ locations to test and revise their planetary motion equations.
By the time of the Great Conjunction on July 16, 1623, the planetary pair was less than 13° east of the sun. By Civil Twilight, the pair was near the horizon at mid-latitudes. Without optical help, the conjunction likely went unobserved, even for those with recently minted telescopes. Even then, the observer needed some luck to find the conjunction.
In later years, two British publications stated that the 1623 conjunction was not observed. In 1886, the Monthly Notices of the Royal Astronomical Society state that the February 8, 1683, Jupiter – Saturn conjunction was the first observed “since the invention of the telescope” and that the 1623 passing went unobserved. The same statement was written in the Journal of the British Astronomical Association in 1897. Perhaps the conjunction was observed without optical aid and recorded from more southerly latitudes, when the planets were higher in the sky.
Did the two British publications make the statements out of parochialism, rather than from factual observations made around Europe regarding the first Great Conjunction observed with a telescope, or was this the first time that the conjunction fit into an eyepiece since the telescope’s invention? The February 24, 1643, conjunction was visible in the western sky during mid-twilight as well as the October 16, 1663, conjunction. At the second conjunction the planets were about 10° up in the southwest at one hour after sunset. However, at both conjunctions, the planets were nearly 1° apart. At the 1683 conjunction, the planets were close, about 0.2° apart, twice the separation of the upcoming event. While the two previous conjunctions were visible to the naked eye and individually in a telescopic eyepiece, the 1683 conjunction was the first observed with both planets simultaneously in an eyepiece. With a separation of 0.1°, the 1623 conjunction would have fit into telescopes eyepieces of that generation, but certainly those early telescopes were unwieldy to steer and hold steady, and the telescope operator needed some persistence during the days preceding the conjunction to follow the converging planets into bright twilight while they had sufficient altitude to observe them. So, while the British publications are accurate about viewing the planets simultaneously through a telescope, the two preceding conjunctions were visible to the unaided eye and individually through a telescope, and this does not speak to the issue as whether the 1623 conjunction when unobserved across all of humanity.
In recent times, Great Conjunctions occurred February 18, 1961; followed by a triple conjunction of the two planets in 1980-81; and the last occurred May 30, 2000, although this was difficult to observe.