Tag: Planets

Astronomy, Sky Watching

2020, February: Evening Star Venus, Mercury, and Moon
Venus Shines in Southwestern sky
2020, January 19: Venus is visible in the southwest about 40 minutes after sunset. The planet is now setting over 3 hours after sunset.

Brilliant Venus sparkles in the western sky after sunset.  It is so bright that Earth’s neighbor is often mistaken for a passing airplane.  Find Venus throughout February during the early evening hours.

The speedy planet Mercury pops into the evening sky after sunset for its best appearance of 2020.  As Mercury appears higher in the sky, it dims.  Find a clear horizon in the west-southwest and begin looking at about 45 minutes after sunset. It appears as a bright star.  Try to catch it early in its appearance and look for it each evening as it appears higher in the sky, but it is dimmer nearly every evening.  First attempt to look for it with a binocular; then look without optical help.

By mid-month, you’ll need a binocular to find it in the sky, as it much dimmer.

Venus appears high above Mercury.

Venus and Moon February 2020

The moon joins Venus late in the month.  On February 25, find a clear western horizon about 1 hour after sunset.  Each evening the moon is higher in the sky than the previous evening.

The best evening is on February 27, when the moon and Venus seem to appear in a scene of an artist.  Both are nearly at the same altitude above the horizon.  The moon is about 7° to the left of Venus.

You can capture “earthshine” on the night portion of the moon with a tripod-mounted camera.  Exposures ranging from 1 to 10 seconds reveal that the night is gently illuminated by sunlight reflected from Earth.

Here are more details about the moon’s appearance:

  • February 24: The moon returns to the evening sky. Thirty minutes after sunset, the moon (1.4 days past New, 2% illuminated) is nearly 6° up in the west-southwest. It is over 30° below brilliant Venus (m = −4.3).
  • February 25: In the evening sky, one hour after sunset, the moon (2.4d, 5%), over 10° in altitude in the west-southwest, is nearly 20° below Venus.
  • February 26: The moon is at apogee at 5:34 a.m. CST, 252,449 miles away. One hour after sunset, the moon (3.4d, 10%) is over 20° in altitude in the west-southwest. The lunar crescent is about 10° below brilliant Venus.
  • February 27:  In the evening, Venus and the moon (4.4d, 16%) are in a classic artist’s scene. Brilliant Venus is 6.7° to the right of the lunar crescent. Photograph the pair with a tripod-mounted camera. Vary exposures from 1-10 seconds to capture earthshine on the night portion of the moon.
  • February 28:  One hour after sunset, the waxing crescent moon (5.4d, 24%) is over 40° in altitude above the west-southwest horizon. It is nearly 15° to the upper left of brilliant Venus.
  • February 29: Happy Leap Day! In the evening, about one hour after sunset, the thick crescent moon (6.4d, 33%) is over 50° up in the southwest. Brilliant Venus is over 30° up in the west-southwest.

Happy Observing!

Astronomy, Sky Watching

2020, January 21: Mars, Moon, and Antares

Mars, Moon and Anatres January 21, 2020

During a cold, clear morning in the Chicago area, the planet Mars is about 5 degrees to the upper left of the star Antares, the Red Planet’s rival.  The star is about the same color and brightness as Mars when the planet passes by about every 2 years.

This morning the old moon (overexposed in the image above) appears to the lower left of the Mars-Antares pair.  Notice that the night portion of the moon is gently illuminated by the sunlight reflected from our planet.

See more about where to locate Mars.

Astronomy, Sky Watching

2020, January: Venus Sparkles in Evening Sky

Venus begins the New Year among the dimmer stars of eastern Capricornus. Now setting about 3 hours after the sun, watch Venus move eastward into Aquarius and toward a Neptune conjunction.

See our article about Venus as an Evening Star, 2019-2020

As the New Year opens, brilliant Venus is 35° east of the sun, setting nearly 3 hours after sunset.  Use a binocular to track Venus against the dimmer starfield.

On January 6 About an hour after sunset, Venus, nearly 18° up in the southwest, is 0.8° to the upper right of Gamma Capricorni (γ Cap, m = 3.6).

A few nights later, January 8, at an hour after sunset, Venus, nearly 19° up in the southwest, is 0.9° to the upper right of Delta Capricorni (δ Cap, m =2.8).

On January 11 Venus moves into the dimmer starfield of Aquarius.

Now setting in a dark sky on  January 20, over three hours after sunset, Venus is 4.3° to the upper right of Tau Aquarii (τ Aqr, m = 4.0).

Venus Shines in Southwestern sky
2020, January 19: Venus is visible in the southwest about 40 minutes after sunset. The planet is now setting over 3 hours after sunset.

On January 23 about an hour after sunset, Venus, 23° up in the southwest, is 1° left of Lambda Aquarii (λ Aqr, m = 3.7) and 4.5° to the lower right of Neptune (m = 7.9).

On January 26, through a telescope observe that Venus is 75% illuminated, an evening gibbous phase that is 15” across.

Near month’s end, on January 27, Venus is 40° east of the sun. At the end of evening twilight (about 6:30 p.m.), Venus, 18° up in the west-southwest, is 0.2° to the upper left of Neptune, nearly 7° above the crescent moon (3.1 days past the New phase, 9% illuminated) and 0.2° to the lower right of Phi Aquarii (φ Aqr, m =4.2).

The moon continues its appearance with Venus.  On January 28, at the end of evening twilight Venus, about 18° up in the west-southwest, is 7° to the lower right of the moon (4.1d, 15%).

Astronomy, Feature, Sky Watching

2020: The Evening Sky

2020 Setting Sky in west

This chart shows the summary of the setting of the naked-eye planets, moon, and bright stars near the ecliptic, the plane of the solar system, for 2020. The chart shows the setting of these celestial bodies compared to sunset for time intervals up to five hours after the sun’s disappearance. The three phases of twilight are displayed as well. On this chart, activity occurs in the western sky, except for the rising curves (circles) of Jupiter, Saturn and Mars. When they rise in the east at sunset, they are at opposition.

As 2020 opens, Venus is the bright Evening Star, appearing in the southwest. Mercury makes its best evening appearance, setting at the end of evening twilight during early February. Mercury’s June elongation is larger, but it sets several minutes before the end of twilight, making it difficult to observe in the brighter sky. After Venus moves past the Pleiades and Aldebaran, it moves toward Elnath (β Tauri), and then plunges toward its inferior conjunction. Jupiter and Saturn pass opposition during July. After Venus disappears from the evening sky, the slow procession of bright stars – Pollux, Regulus, Spica, and Antares – disappears into evening twilight. Jupiter and Saturn appear on the setting chart in late October, just after Mars reaches opposition. The moon has two interesting appearances with the planetary duo on November 19, 2020 and just days before the Jupiter- Saturn Great Conjunction on December 21, 2020.

The chart is calculated from data by the U.S. Naval Observatory, for Chicago, Illinois.

Key to symbols: White square, conjunction; yellow triangle, greatest elongation (GE); yellow diamond, greatest brightness (GB).

 

Astronomy, Feature, Sky Watching

2020: The Morning Sky

2020 Rising Chart

This chart shows the summary of the rising of the naked-eye planets, moon, and bright stars near the ecliptic, the plane of the solar system, for 2020. The chart shows the rising of these celestial bodies compared to sunrise for time intervals up to five hours before the sun’s appearance. The three phases of twilight are displayed as well. On this chart, activity occurs in the eastern sky, except for the setting curves (circles) of Jupiter, Saturn and Mars. When they set in the west at sunrise, they are at opposition.

Early in the year, the morning sky offers the three Bright Outer Planets – Jupiter, Saturn, and Mars – in the eastern predawn sky. As Mars moves eastward it passes Antares, Jupiter and Saturn. On several mornings, the moon passes the planetary trio. The highlight occurs on the morning of February 18 as the moon occults Mars as sunrise approaches in the Central U.S. Venus enters the morning sky at mid-year. The appearance of a lunar crescent with the brilliant planet is a beautiful sight. The moon appears with Mercury as the planet enters the morning sky in late July. On the morning of July 19, the moon and the five naked eye planets are in the sky. As the moon moves toward its evening appearance, Mercury appears higher in the sky, making it a little easier to see. Venus reaches its period of greatest brightness; the mid-brightness date is marked by the yellow diamond. Venus moves past Aldebaran, Pollux, Regulus, and Spica as it moves towards its superior conjunction in early 2021. Mercury’s best morning appearance occurs during November. While this is its smallest morning elongation, the angle of the ecliptic places it higher in the sky.

The chart is calculated from data by the U.S. Naval Observatory, for Chicago, Illinois.

Key to symbols: White square, conjunction; yellow triangle, greatest elongation (GE); yellow diamond, greatest brightness (GB).

Astronomy, Sky Watching

2019, December 21: Winter Solstice, A Long Time in Arriving

A wintry snow scene

The winter solstice (in the northern hemisphere) is here on December 21 at 10:19 p.m. CST.  The sun reaches its lowest point in the sky and daylight is short.  The darkness around the solstice is a long period.  On December 1, the sun was in the sky 9 hours, 23 minutes (in Chicago) and at other locales at or near this latitude.  On the solstice, daylight’s length is 9 hours, 8 minutes.  Afterward, there is not a sudden snap to longer daylight.  By January 10, three weeks after the solstice, daylight stretches only 12 minutes to 9 hours, 20 minutes.  The length of daylight begins to stretch, nearly 10 hours by the end of January.

Without carefully watching the sun and a calendar, and lack of some astronomical calculations, the date of the solstice would be difficult to determine by experiencing the colder, darker time alone.

A better indicator of the solstice is the starry night sky.  As the sky is fully-darkened, when most are inside to keep warm from the day’s work, magnificent Sirius gleams low in the eastern sky.  (Venus sparkles wildly in the west at solstice time 2019.)  The Dog Star makes its presence known as it twinkles randomly from its low position.  The Little Dog Star, Procyon, shines to the upper left of Sirius.  Rigel and reddish Betelgeuse shine from above Sirius.

So while daylight finally dwindles to its minimum for this solar cycle, the reliable repetition of the annual stellar rhythms tell us that longer daylight is ahead, although it’ll take a several weeks to notice the change.  Happy Solstice time!  For me, it’s Christmas, so I wish you a Merry Christmas.  Have a blessed holiday.