November 30, 2022: Earth is closest to Mars this evening at 8:16 p.m. CST. The Red Planet appears as a bright star in the night sky. Tonight is the Venus-Mars Opposition.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:58 a.m. CST; Sunset, 4:21 p.m. CST. Check local sources for sunrise and sunset times for your location.
The moon is at the First Quarter phase at 8:37 a.m. CST. The moon is below the horizon from the western hemisphere.
Mars is closest to Earth tonight at 8:16 p.m. CST. The distance is 0.544 astronomical unit (AU), where an AU is about 93 million miles away. This closest approach is the smallest gap between the two planets until July 5, 2033, when they are 0.423 astronomical unit apart.
This closest approach should not be confused with opposition, when Earth is between an outer planet and the sun. This occurs with Mars on December 7th.
Because Mars orbit is elliptical, Earth and the Red Planet are closest either before or after our planet passes between Mars and the sun. If Mars is still heading toward aphelion, the point in the orbit farthest away from the sun, the closest approach occurs before opposition. The two events can occur up to about a week apart and rarely on the same date. In 2027, the events are less than nine hours apart.
Mars average distance from the sun is 1.52 AU compared to Earth’s 1.0 AU. Mars revolves around the sun in roughly two Earth years. Because of the relatively close distance and speed, Earth passes Mars about every 25 months. These close approaches occur in that time interval. Because Mars is only half Earth’s size, telescopes are turned toward the Red Planet near these closest approaches and oppositions to see polar caps, surface features, and sometimes global dust storms. Robot spacecraft are launched into solar orbits toward Mars a few months before these times, because Earth is moving toward Mars.
This apparition’s shortest distance is over 40% farther away than when the minimum distance occurred when Mars was near its perihelion – closest point to the sun – a so-called perihelic opposition occurred in 2018. Mars’ moons were first observed during a perihelic opposition in 1877. During the 1894 close opposition, Percival Lowell made his first observations of Martian “canals,” now known to be illusions.
After this year’s closest approach, the next two approaches occur when Mars is closer to its aphelion – aphelic oppositions. On January 12, 2025, Mars is 18% farther away than this year’s closest approach. During the February 20, 2027, approach, the Red Planet is 24% farther away than this year’s distance and 84% farther away than the close 2018 distance.
After the far-away 2027 distance, Mars is at its aphelic opposition every 13-15 years. Future separations are nearly as far away as this distance. Astronomer Jean Meeus’ calculations indicate that the Earth-Mars separation grows larger than the 2027 minimum distance when Earth passes by in 2390, 0.67803 astronomical unit.
This is the time to ask the neighborhood sky watcher to show you Mars, Jupiter, and Saturn through their telescope. With earlier sunsets, the three planets are nicely placed for evening viewing.
Through a telescope, Mars is a red-ochre globe. It is tinier than might be expected, since it is the second closest planet to Earth, after Venus and only half Earth’s size. View the planet for long periods, not just a quick glance of a second or two. Allow your eye to adjust to the planet’s brightness and look around the globe. Depending on the time of night, various features appear in the center of the planet.
Winter began in the Martian northern hemisphere on July 21st and ends December 26th. The northern hemisphere is tilted away from the sun, but since it’s winter, it is large. The southern cap is reduced by the Martian summer there. Both might be hiding in clouds, known as the polar hoods.
Here is today’s planet forecast:
As opposition approaches, Mars is lower in the morning sky each night. An hour before sunup, find it about 20° up in the west-northwest, 5.1° to the lower left of Elnath, the northern horn of Taurus.
Mars is retrograding in front of Taurus. This illusion occurs when Earth passes between Mars and the sun. The line of sight, that normally moves eastward compared to the sidereal backdrop, shifts westward, making it seem that the planet is backing up compared to the stars. This continues until nearly mid-January 2023.
Mars is the brightest star in the sky this morning. Notice its red-orange color compared to Aldebaran – the brightest star in Taurus – and Betelgeuse – the shoulder of Orion.
Venus and Mars are at opposition tonight. From Earth, Mars is in one direction and Venus is in the opposite direction – opposition. They are 180° apart in the sky. Evening planet-to-planet oppositions, such as this one, indicate that the two planets are becoming visible simultaneously, as well as any planets between them in the sky.
With this planet-to-planet opposition, the classic eight planets – along with us standing on Earth – are together at the same time. The Mars-Mercury opposition occurred yesterday. On the chart above notice the proximity of Mercury to Venus as viewed from Earth.
Venus and Mercury are just east of the sun, still setting shortly after sundown. Venus sets thirty-three minutes after the sun sets, while Mercury follows two minutes later. During the next three weeks, Mercury and Venus emerge from bright sunlight to appear with bright Mars, Jupiter, and Saturn, another five-planet display. The moon joins them as well near year’s end. From December 24 to December 28, from the sunset point eastward, the order is Venus, Mercury, Saturn, Jupiter, and Mars. Uranus and Neptune are there as well. By then, Pluto is immersed in bright sunlight.
This evening the slightly gibbous moon, 54% illuminated, is over one third of the way up in the south-southeast at one hour after sunset. It is 16.0° to the lower right of bright Jupiter and nearly 25° to the left of Saturn.
Jupiter is over 40° up in the southeast. It is moving slowly eastward in front of Pisces. The starry background is dim behind the Jovian Giant.
Saturn, one-third of the way up in the south, is moving eastward with Capricornus. This evening’s gap to Jupiter is 39.0°.
Notice the brighter stars in the same region. They are Deneb Kaitos – the tail of the sea monster – to the lower left of Jupiter, and Fomalhaut – the mouth of the southern fish – less than 20° up in the south, below the moon.
At 5:31 p.m. CST, Jupiter’s Great Red Spot is visible in the southern hemisphere at the center of the planet for sky watchers with telescopes. At this time the planet is in a favorable view from the Chicago area, but higher for sky watchers in the eastern Americas.
The long-lived “storm” swings into view about every 10 hours from the planet’s rapid rotation. It is visible two to three times a day. It appears for nearly two hours centered on the predicted time for its best viewing.
Mars rising time is approaching sunset. On December 7th, the planet is at opposition with the sun – with Earth between the two bodies. Like Venus and Mars are 180° apart tonight, Mars and the sun are at the same angle. The planet rises at sunset, appears near the south point at midnight, and sets in the west at sunrise. Mars’ nightly movement is opposite the sun’s motion.
As noted previously, Earth and Mars are closest this evening. The actual time is noted, but seeing Mars at this particular moment is not essential. Telescopic observations provide favorable views during the next several days.
By three hours after sunset, Jupiter is about halfway up in the south, while the moon is to its lower right. Mars is about 20° above the east-northeast horizon and Saturn is the same height above the horizon in the southwest.
During the night, Saturn, the gibbous moon, and Jupiter set in the western sky. By morning twilight, Mars is low in the west.
- 2023, October 23: Venus at Greatest ElongationOctober 23, 2023: Venus moves to its farthest angular distance from the sun today, known as greatest elongation. During morning twilight, the Morning Star passes Leo’s Chertan.
- 2023, October 22: Moon Approaches SaturnOctober 22, 2023: During evening hours, the gibbous moon nears Saturn in the southern sky. Venus and Jupiter are visible during morning twilight.
- 2023, October 21: Three Bright Planets, First Quarter MoonOctober 21, 2023: Venus, Jupiter, and Saturn are easy to locate during nighttime hours. The First Quarter moon phase occurs this evening.
- 2023, October 20: Jupiter’s Double Shadows, Mercury at Superior ConjunctionOctober 20: After midnight, Jupiter’s moons’ shadows dance across the cloud tops. Mercury is at superior conjunction.
- 2023, October 19: Poured Moon, See Planet UranusOctober 19: Sagittarius seems to pour the moon into the sky this evening. Find Uranus with a binocular.