Four bright planets – Venus, Mars, Saturn, and Jupiter – parade across July’s morning sky.
by Jeffrey L. Hunt
A mostly cloud-free sky prevailed before sunrise, when four bright planets stretched across the sky from the east-northeast tree line to the southwest skyline.
Brilliant Venus – the fourth planet in the morning planet parade – shines from low in the east-northeast this morning during twilight. The planet is near the Hyades star cluster in the constellation Taurus. During the next two weeks the planet appears to move through the cluster. While not visible without a binocular and in a time exposure, the stars of the cluster are identified.
Venus is 0.9° to the upper right of Delta1 Tauri (δ1 Tau) on the photo above. Theta1 Tauri (θ1 Tau) and Theta2 Tauri (θ2 Tau) are identified as well. The bright star Aldebaran is still below the tree line at the time of the photograph.
The parade of planets begins when Jupiter rises in the east-southeast about 40 minutes after sunset, followed by Saturn about 20 minutes later. By two hours after sunset, they are low in the southeast.
As midnight approaches, the giant planet pair is in the south-southeast. By 1:30 a.m. CDT, Mars is low in the east. The nights are still short during July as twilight begins over two hours before sunrise.
By one hour before sunrise, Jupiter and Saturn are in the southwest, followed by Mars. Venus joins the morning planet parade as it rises two hours before sunrise, gleaming brightly in the east-northeast as twilight is in progress. At that time, the morning planet quartet stretches across the morning sky.
Mars shines from among the stars in southern Pisces. Note the position of Mars compared to 29 Piscium (29 Psc) compared to where it was a few days ago. Mars continues its eastward march compared to the starry background. On July 8, Mars moves into Cetus for 19 days. Then it moves back into Pisces.
With a binocular watch Mars move near two dimmer stars in Cetus, 14 Ceti (14 Cet) and 20 Ceti (20 Cet).
Meanwhile, the parade leaders, Jupiter and Saturn, are in the southwest. Jupiter is in front of the stars of eastern Sagittarius. Saturn is in the stars of western Capricornus.
Jupiter and Saturn are retrograding, an illusion as our planet approaches and passes them. Normally, the planets appear to move eastward compared to the stars, like what we see currently with Mars.
Earth passes Jupiter on July 14 and Saturn 6 days later. This is known as opposition. The planet and the sun appear in opposite places in the sky and they seem to do the opposite actions of the other.
When the sun sets, the planet rises. At midnight (1 a.m. during daylight time), the planet is in the south, when the sun is in the south at noon (1 p.m. during daylight time). The planet sets in the western sky when the sun rises in the east.
Mars begins to retrograde in September and is at opposition on October 13, 2020.
As Jupiter and Saturn retrograde they appear to separate. This morning the gap is 6.1°.
In a few mornings Saturn moves westward into Sagittarius. With a binocular, watch its westward progress compared to Sigma Capricorni (σ Cap). This morning Saturn is 3.0° from the star. Jupiter is 2.1° below the star 56 Sagittarii (56 Sgr).
During September Jupiter and Saturn resume their normal eastward motion compared to the stars. Jupiter overtakes and passes Saturn in a once-in-a-generation Great Conjunction on December 21, 2020. This is the closest conjunction of the planets since 1623.
An hour before sunrise, stand in an open area to trace the plane of the solar system across the sky from Venus to Jupiter.
Mercury joins the parade beginning July 19 when the “Classic 9” planets are in the sky simultaneously along with the moon.
For more about the planets see this article about where to find them during July.