It was almost exactly a year ago when the naked eye comet named ‘NEOWISE’ graced the morning and evening skies of early summer.
A close up of Comet NEOWISE’s nucleus and coma, along with part of its tail. Photo was taken in July 2020.
Twice this week, I observed with the naked eye what looked like a comet in the partly cloudy western twilight.
Bright object pointing down toward the WNW horizon, about 9:15pm MDT on June 25, 2021.
The object wasn’t a comet, it was an atmospheric event that some refer to as a ‘Venus pillar.’ NASA says Venus pillars are rare occurrences. In fact, the phenomenon is so rare that it doesn’t have an agreed upon name, although ‘Venus pillar’ seems appropriate since it’s similar to a ‘Sun pillar.’
A Sun pillar (a.k.a., light pillar) is light from the Sun, located just above or below the horizon, reflecting off horizontal ice crystals floating in the upper atmosphere. The reflection results in a vertical shaft of light, slightly bulging at the Sun’s position. If the Sun is above the horizon, the Sun pillar can appear above and below the Sun. If the Sun is just below the horizon, the shaft of light will rise vertically above the horizon, from the point directly above the recently set Sun.
A Sun pillar stands over the Jemez Mountains. Photo taken in April 2021.
With this week’s unusually cool, moist weather, ice crystals formed in the upper atmosphere. On two occasions, the planet Venus was close enough to the horizon and bright enough to create a mini-light pillar, above and below the planet.
In the second photograph above (the ‘bright object’ photo), a thick cloud blocked the lower half of the Venus pillar, creating a comet-like effect. The two photos below show the Venus pillar in its entirety.
A Venus pillar seen on June 25th, around 9:30pm MDT. One could argue that this is a Sun pillar since the pillar is created by sunlight reflecting off of ice crystals in Earth’s atmosphere – the sunlight just happened to reflect off of Venus’ cloud tops first!
A second Venus pillar, seen on June 27th, about 9:40pm MDT. Note the gibbous phase of the planet. The pillar bulges a bit in the middle, then appears to taper at the tips like a candle flame.
In all my time watching the sky, I’d never seen a Venus pillar. Now, I’ve seen two in one week.
The Moon was officially full at 12:40pm MDT on Thursday June 24th. At that time, the Sun, Earth, and Moon were aligned, with Earth in the middle. Because the Moon was near perigee in its orbit around Earth (‘perigee’ is the term used to describe an orbiting object’s closest approach to the object it orbits), it appeared slightly larger than average – hence the misleading name, ‘supermoon.’
The term ‘supermoon’ was actually coined by an astrologer. But, there’s nothing super about a supermoon, at least from an astronomical perspective. In fact, you wouldn’t know you were looking at a supermoon, unless somebody told you so.
The media likes to use terms like ‘supermoon’ to generate interest and excitement. They called the January 2019 total lunar eclipse, the ‘Super Blood Wolf Moon’ because it was a) a supermoon; b) an eclipsed moon, in which the Moon appears reddish; and c) some Native American tribes refer to the January full moon as the ‘Wolf Moon’ because hungry wolves are said to howl more on cold winter nights.
Personally, I think the hype does astronomy a disservice since it encourages people to go out and look at the night sky, thinking they’re going to see something really different and exciting, but come away disappointed because the Moon didn’t fill half the sky or rise dripping in blood.
OK, back to this week’s supermoon. Because the Moon was full at about midday on Thursday, it appeared to be virtually full on both Wednesday and Thursday evenings. Wednesday evening was pretty cloudy, but I managed to photograph the Moon through a large rift in the clouds.
When the Moon is full, there’s little detail to be seen on the surface, due to the lack of shadows. The full moon is beautiful to the unaided eye, but doesn’t show much more than light and dark patches, even in a telescope.
The light patches are called the ‘lunar highlands’ – these are geologically old surface materials (mainly igneous rock), which are heavily cratered.
The dark patches are known as ‘lunar maria’ or ‘lunar seas’ – the result of lava flows. Because the lava flows are more geologically recent than the lunar highlands, the maria are lightly peppered with craters, as compared to the heavily bombarded highlands. Many of the lunar maria appear round – this is due to lava flowing into and filling ancient impact basins.
In the attached photo taken on Wednesday, about 16 hours before full, you can see a little bit of relief along the lower left limb since there’s a just a sliver of night at the very edge. The rest of the Moon seems flat and featureless, although the maria and highlands are obvious due to their differences in brightness and color.
One exception is the bright, rayed crater, Tycho, easily seen at the lower right. Tycho’s 53-mile-wide crater was formed about 100 million years ago – likely the result of impact with an asteroid. Ejecta from the impact was blown across the surface of the Moon, creating the bright rays we see today. The longer rays are over 900 miles long.
The Moon, photographed on Wednesday night, about 16 hours before full.
Contrast Wednesday’s photo of the Moon (above) with the photo taken on Thursday, about ten hours after full (below). The lower left limb is now devoid of relief; the only visible surface detail is along the upper right limb. This is due to the fact that the Moon is now waning (past full). The sunrise terminator we saw before full has now moved beyond the visible portion of the Moon. But, the sunset terminator is now beginning to stretch along the right edge.
The Moon, photographed Thursday night, about ten hours after full.
Finally, check out the photo of the Moon below, taken Friday, about 35 hours after full moon. The sunset terminator has shifted to the west, compared to the Thursday photo, and the waning gibbous moon has taken on a slightly oval shape. Relief is obvious now, with numerous, shadow-filled craters spread along the upper right limb. The terminator provides the contrast of light and shadow, turning seemingly uninteresting markings into stark, three-dimensional relief.
The Moon, photographed Friday night, about 35 hours after full. The bright eastern crater walls along the sunset terminator at the upper right catch the last rays of the Sun, while the crater floors are filling with shadows created by the western walls.
The Moon, our closest neighbor, is often overlooked by those seeking planets and deep sky objects. It’s even seen as a nuisance, spreading light into the night sky, making it more difficult to view everything from star clusters and nebulae to meteors. I know the Moon is sometimes seen in a bad light (excuse the pun) because I sometimes fall into this trap.
But, the Moon is actually a never-ending source of interest and fascination, even in binoculars and small telescopes. If you focus on the terminator, you’ll see new features every night that may have escaped your eye the night before. So, embrace the Moon and marvel in its ever-changing face.
The beginning of the southwest monsoon season offers another summer’s entertainment – storm watching. I enjoy sitting on the portal on a summer evening, watching lightning flash from the clouds miles away. Last night, we were treated to an early storm spectacle, while receiving not a drop of rain, at least in my neighborhood.
About an hour after the Sun had set, I noticed a rain curtain developing over Santa Fe. Despite the growing darkness, the rain curtain seemed to be more, rather than less visible from my vantage point, about ten miles south of town. This was due to the lights of Santa Fe lighting the veils of rain from below.
Not a pretty sunset. The lights of the Santa Fe area reflect off of rain veils and storm clouds to the north. The Sun had set about 50 minutes before this photo was taken. Light pollution illuminated the rain veils and left a dirty red ‘stain’ on the clouds above.
What began as a sporadic lightning display became quite active as twilight gave way to night. Numerous bolts appeared to descend to Earth. However, it was weirdly quiet from my location (not to mention dry).
Lightning appeared to ‘pound the ground’ to the north, again and again, but nature’s artillery barrage was profoundly silent. According to my weather app, the lightning was about 20 miles away.
Hopefully, this monsoon season will produce more storms and rain than last year’s season. If so, enjoy the evening light shows.
The Moon and Venus made a nice pair in the WNW twilight on the evening of June 11th. Here are a few photos of the event.
The Moon was only 2.3% illuminated as it passed Venus (upper left) after sunset on June 11th.
As the twilight deepened, a faint Earthshine was visible on the Moon’s night side. Many of the dark lunar maria and lighter highlands can be seen on the Moon’s surface. Mebsuta (epsilon Geminorum) is the star one lunar diameter to the Moon’s upper left.
The Moon was poised to set behind the Jemez Mountains.While the Moon is a slim crescent, just past new moon, Venus is almost full since it’s on the far side of the Sun, as seen from Earth.
The clear, relatively light pollution-free WNW horizon allowed us to observe the Moon-Venus conjunction to the very end.
It takes a clear, dark sky to see the night side of the Moon after the day side had set. Third magnitude Mebsuta would soon follow the Moon behind the Jemez (Venus was still visible, but was beyond the left side of the frame).
I’ve been watching the skies for 50 years and somehow an easy-to-observe fact eluded me.
Evening twilight is sunlight from the recently set Sun, scattering in the Earth’s upper atmosphere and spreading laterally along the horizon. Twilight continues until the Sun is 18 degrees below the horizon, at which point the sunlight is no longer visible and night officially begins.
I always thought of evening twilight as occurring above the western horizon, spreading into the northwest and southwest (‘twilight’ occurs in the morning, too, but many of us refer to morning twilight as ‘dawn’).
Last evening, I observed that my understanding of evening twilight wasn’t exactly correct. Since we’re now only two weeks from the summer solstice (the northernmost point that the Sun appears to travel — the apparent motion of the Sun is due to the Earth’s rotation and the Earth’s orbit around the Sun), the location of sunset has shifted well to the north of west. Because of this, and because the Sun at this time of year sets at a shallow angle with respect to the horizon, twilight has shifted toward the north, as well.
The photo below was taken last evening (June 8), looking northwest (West is beyond the left side of the frame). As you can see, evening twilight spread far into the northwest — so far, in fact, that it passed true north and could be seen along the north-northeast (NNE) horizon. Evening twilight in the NNE???
Before last evening, if someone told me that they’d seen something in the evening twilight above the NNE horizon, I’d have tried to correct them. Now, I’m the one who stands corrected.
Unbeknownst to me (until now), for several weeks before and after the summer solstice, evening twilight can be seen in the NNE from our vantage point on Earth. The proof is in the pudding — well, it’s in the photo, anyway.
The springtime constellations are well-placed in June’s evening skies, but begin to give way to the summer constellations that follow. Scorpius is the first summer constellation to rise, its head popping up above the ESE horizon at sunset in early June. Venus emerges from the twilight into darker evening skies, lighting up the WNW. Summer solstice occurs on June 20th, the Sun appearing above the Tropic of Cancer on that date. After the solstice, the Sun begins its six month trek south. On June 24th, we’re treated to a full supermoon.
At the beginning of the month, Mercury is still an evening object, albeit a difficult one, requiring binoculars to see as it moves back toward the Sun. Our innermost and fastest planet passes the Sun and becomes a morning object in late June, gracing the constellation Taurus.
Bright Venus and dimming Mercury (slightly below and to the left of Venus) made a close pair in the sunset sky on May 28th.
Venus starts June above Mercury, in Gemini. The brightest object in the evening sky, our ‘sister planet’ moves higher above the WNW horizon all month, ending June near Mars, in Cancer.
Mars continues to fade in the WNW as it recedes from Earth, moving from Gemini into Cancer. At the end of June, the Red Planet sets about 10:20pm MDT, just after twilight ends.
Saturn starts June as a morning object, rising in Capricornus about 12:25am MDT. At the end of June, Saturn is an evening object, rising in the ESE about ten minutes after Mars sets on the opposite side of the sky.
About an hour after Saturn rises, Jupiter chases Saturn into the ESE. Our solar system’s largest planet, Jupiter, in Aquarius, moves from the morning to the evening sky during June, by far the brightest object in the neighboring fall constellations.
Jupiter (left) and Saturn (2 o’clock from Jupiter, just above the cloud) rise to the east of the Milky Way in late April.
The constellation Scorpius, the scorpion, is the first of the summer zodiac constellations to appear in June’s skies. In Indonesia, the constellation is known as ‘kalapa doyong’ (‘the leaning coconut tree’). Ancient Hawaiians called the constellation ‘Ka Makau Nui o Maui’ (‘the Big Fishhook of Maui’), Maui being a Polynesian demi-god. In Navajo mythology, the stars of Scorpius form ‘Altse Etsoh,’ the ‘First Great One’. The star we call Antares marks the heart of Altse Etsoh.
Our constellation maps tend to follow Greek and Roman mythology. Located in the heart of the scorpion, the brightest star in Scorpius is Antares, ‘the rival of Ares,’ Ares being the Greek equivalent of the Roman god of war, Mars. The name is due to Antares’ similarity to the planet Mars, in terms of color and brightness. Because Antares is located near the ecliptic (the invisible path that the Sun and planets follow, as seen from Earth), every few years, Mars passes close to its anti-namesake, allowing us to easily see their similarity.
The core of the Milky Way runs through the constellation Scorpius, seen right of center. Antares is the bright red star above and right of center. You can see the dark dust clouds of the Rho Ophiuchi Cloud Complex, just above Antares.
On June 3rd, Antares is at opposition to the Sun, rising in the ESE at the same time the Sun sets in the WNW. Because of this, the star is visible from twilight to dawn during the month of June.
Antares is a red supergiant star, its diameter is 700 times that of our Sun. Earth would not exist in the Antares solar system since the star is so massive, Earth’s orbit would be well inside the star. In fact, the star is wider than the orbit of Mars, so Mars wouldn’t exist, either – I guess the anti-Mars wins…
Antares is a variable star, its brightness fluctuating between magnitudes 0.6 and 1.6. It’s also a binary star, meaning that it has a companion star, the two stars revolving around a common center of gravity. The companion star is called Antares B. It’s blue-white, a marvelous contrast to Antares’ red, and at magnitude 5.5, is much dimmer than the primary star.
Antares appears to sit within the Rho Ophiuchi Cloud Complex, an area of dust and gas that gives birth to stars. About 425 light years distant, the Cloud Complex is one of the closest stellar nurseries to our solar system. Antares is 550 light years away, so while it appears to be part of the Rho Ophiuchi Cloud Complex, it’s actually well behind and shining through it, as seen from Earth.
The Rho Ophiuchi Cloud Complex. Antares is the bright star below and left of center. The globular cluster Messier 4 is to the right of Antares. A second, smaller globular cluster, NGC 6144, can be seen above and to the right of Antares.
Photo credit: Adam Block, Steward Observatory, University of Arizona.
June Night Sky Events:
June 10: New moon.
June 11: A thin crescent moon and Venus make a close pair in the evening twilight.
June 13: The Moon passes Mars in Cancer.
June 20: Summer solstice occurs at 9:21pm MDT when the Sun is at its northernmost position in the sky, as viewed from the northern hemisphere.
June 24: A full supermoon occurs at 12:40pm MDT. The Navajo people call a full moon, ‘haniibaaz.’
May’s full supermoon rises before the sun sets, giving it an indistinct appearance until the sky darkens.