A Recent Venus-Mars Conjunction
On an interval that varies from several days to nearly 23 months, Venus and Mars can appear very close together in the sky. These conjunctions can be very close (Epoch) or with very wide separations. During the conjunction displayed in the above image (November 3, 2015), the planets appeared about 0.7 degree (42 minutes) apart. On October 5, 2017, they appear over 3 times closer with a separation of .22 degree (13.2 minutes). (In the sky we measure the separation of objects by a geometric angle as seen from Earth. The full moon’s diameter is about 0.5 degree. Your little finger at arm’s length covers a full moon. Try it during the next time the moon is full. In the above image Venus and Jupiter are separated by about 7 degrees. Your fist at arm’s length covers about 10 degrees in the sky.)
At its brightest, Mars shines as the third brightest starlike object in the sky, following Venus and Jupiter. This occurs when Mars is at opposition, when it is closest to Earth and opposite the sun in the sky. At opposition, Mars rises in the east at sunset, appears in the south at midnight and sets in the west at sunrise. Conjunctions of Mars (and the planets beyond Earth) with Venus occur when Venus is within 47 degrees of the sun. This angle is the greatest angular separation that Venus has from the sun from our home planet view. Yet, if Venus and Mars appear too close to the sun, they are lost in the sun’s brightness and not visible from Earth. Because Mars is far from our planet during a Venus conjunction, it is not near its maximum brightness, so Venus always appears very bright in the sky and a conjunction with Mars occurs when the Red Planet is dimmer. A Venus-Mars conjunction does not occur when Mars is near its brightest (at opposition) Notice Mars’ brightness in the image at the beginning of this article from the 2015 conjunction.
Notice that Venus does not appear at opposition; so it is not visible at midnight.
At the time of this writing, Venus has recently entered the evening sky and passed its Epoch Conjunction with Jupiter. On September 15,2016, Venus appears low in the sky in the west. Saturn and the star Antares are farther south. Mars is beyond them, about 62 degrees from Venus.
From a view outside the solar system, this 62-degree angle is represented in the chart above. In all these charts, Earth is at the geometric vertex of the angle.
As the dates advance toward the New Year, Venus moves closer to Mars. The chart above shows the setting times of planets, the moon, and selected stars compared to sunset during part of 2017, until Mars disappears into the sun’s glare. On January 1, 2017, notice on the chart that The moon sets close to the time of the setting of Venus (14 minutes difference). This indicates that they appear close to each other in the sky. Mars follows Venus by about an hour.
This chart represents what we see in the sky during the early evening on New Years Day. Venus and the Moon are 4 degrees apart with Mars about 12 degrees to the upper left of Venus.
During January 2017, Venus and Mars appear to move closer together as the setting lines of the two planets begin to converge.
On February 3, 2017, the planets close to 5.5 degrees, with Mars setting 19 minutes after Venus. The chart above shows their close angular proximity, but they are nearly 126 million miles apart in space, over 300 times the distance between the earth and the moon.
In the sky, brilliant Venus dominates the southwestern sky with dimmer Mars 5.5 degrees to its upper left.
After this near meeting, Venus rapidly moves back toward the sun, as indicated by the rapidly decreasing time it sets after the sun as indicated by the setting graph earlier in this article. The planets appear farther apart on the sky as the time difference in their settings increases.
On March 1, the planets are 13 degrees apart with the moon 5 degrees to the lower left of Mars.
By March 15, Venus sets at the beginning of twilight and 4 days later it sets in bright twilight. This is a rapid plunge into the sun’s glare.
On March 25, Venus passes between the earth and sun (inferior conjunction) and rapidly moves into the morning sky. Mars slowly sets earlier each night until it disappears into the sun’s glare toward its solar conjunction on July 27.
In late April, Mars moves through Taurus, which has two prominent star clusters: Pleiades and Hyades. The Pleiades star cluster is a compact cluster of many blue stars. Commonly named the “Seven Sisters,” the cluster is a spectacular sight through binoculars. Mars passes closest to the cluster (3.5 degrees) on April 21. With binoculars the cluster and the planet are be visible at the same time.
The bright star Aldebaran appears in line with the Hyades cluster; its loosely collected stars resemble a check mark. The Hyades cluster is another spectacular view through binoculars.
On April 28, the moon joins the view in the western sky when it is 4 degrees to the upper left of Aldebaran. Mars continues its planetary motion among these stars.
On April 29, Mars and Aldebaran set at the same time, but they are nearly 7.5 degrees apart. By this date, Venus is shining brightly in the morning sky rising about 90 minutes before sunrise.
On May 6, Mars passes 6.5 degrees to the upper right of Aldebaran. A few days later, Mars begins setting during evening twilight, each night setting deeper into the glow after sunset; It moves behind the sun on July 27.
Upcoming Venus-Mars Conjunctions
- October 5, 2017 — 13.2 minutes separation
- August 24, 2019 — 18.6 minutes
- July 3, 2021 — 29.4 minutes
Our images and charts collections are available here –> http://goo.gl/Sfp1ur
See our article about Venus’ evening appearance.
See our article outlining the planets in the evening sky in 2016.