APOD: A Cosmic Triangle (2020 Apr 15)

[APOD Robot]

A Cosmic Triangle

Explanation: It was an astronomical triple play. Setting on the left, just after sunset near the end of last month, was our Moon -- showing a bright crescent phase. Setting on the right was Venus, the brightest planet in the evening sky last month -- and this month, too. With a small telescope, you could tell that Venus' phase was half, meaning that only half of the planet, as visible from Earth, was exposed to direct sunlight and brightly lit. High above and much further in the distance was the Pleiades star cluster. Although the Moon and Venus move with respect to the background stars, the Pleiades do not -- because they are background stars. In the beginning of this month, Venus appeared to move right in front of the Pleiades, a rare event that happens only once every eight years. The featured image captured this cosmic triangle with a series of exposures taken from the same camera over 70 minutes near Avonlea, Saskatchewan, Canada. The positions of the celestial objects was predicted. The only thing unpredicted was the existence of the foreground tree -- and the astrophotographer is still unsure what type of tree that is.

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[RocketRon]

Very scenic.

A very leafless tree, this early in the nthn hemisphere spring.
Hopefully someone Canadian will chime in.

[Guest]

Not Canadian, but Idaho is just across the border... and that looks like a clump of aspen to me. I'd be happy to be corrected.

The neatest thing about aspen (and other relatives) is that they are clonal - each tree sends up shoots from its roots, so what starts from one seedling can become a cluster (like this), a grove of scores of trees, or even a whole forest. In the Fall each clone turns color all at the same time, and an aspen-covered mountain in the distance becomes a tapestry of patches in shades of green, yellow and orange. Some clonal clusters of aspen apparently date back to the Ice Age.

[Ann]

Thank you, that is a very nice APOD! I like both the colors and the composition of the image. The tree "anchors" the sky and the ground and gives the image balance.

The caption said:

The featured image captured this cosmic triangle with a series of exposures taken from the same camera over 70 minutes

Obviously Scott Aspinall used the 70 minutes of exposures to bring out the color of the comparatively (and deceptively) faint Pleiades and the very faint blue nebulosity around the stars, while at the same time not overwhelming the image with the glare of nearby Venus and the extremely nearby Moon. Note, too, that you can see the orange color of red giant background star HD 23712 just above the Pleiades, near the top of the frame.

Oh, and thanks, Guest, for the description of the aspen clonal clusters!

Ann

[orin stepanek]

Oh Wow! Very nice!

[Chris Peterson]

Not Canadian, but Idaho is just across the border... and that looks like a clump of aspen to me. I'd be happy to be corrected.

The neatest thing about aspen (and other relatives) is that they are clonal - each tree sends up shoots from its roots, so what starts from one seedling can become a cluster (like this), a grove of scores of trees, or even a whole forest. In the Fall each clone turns color all at the same time, and an aspen-covered mountain in the distance becomes a tapestry of patches in shades of green, yellow and orange. Some clonal clusters of aspen apparently date back to the Ice Age.

Maybe... but aspens usually grow straight and are free of low branches, except when very young. This looks more like a cottonwood stand to me.

[Lacy Parcell]

The title should have been, A Cosmic Rectangle, as Earth is also in the image.

[neufer]

The title should have been, A Cosmic Rectangle, as Earth is also in the image.

cosmic (adj.) 1640s, "worldly, of this world," a sense now obsolete, from Latinized form of Greek kosmikos "worldly, earthly, of the world," from kosmos "world-order, world." Cosmical "related to the earth" is attested from 1580s. Modern sense of "of or pertaining to the universe," especially as conceived as subject to a harmonious system of laws, is from 1846. Meaning "related to or dealing with the cosmos, forming part of the material universe beyond the earth or the solar system" is from 1871. In reference to inconceivably vast space or protracted time, from 1874.
.........................................................
cosmos (n.) c. 1200, "the universe, the world" (but not popular until 1848, when it was taken as the English equivalent to Humboldt's Kosmos in translations from German), from Latinized form of Greek kosmos "order, good order, orderly arrangement," a word with several main senses rooted in those notions: The verb kosmein meant generally "to dispose, prepare," but especially "to order and arrange (troops for battle), to set (an army) in array;" also "to establish (a government or regime);" "to deck, adorn, equip, dress" (especially of women). Thus kosmos had an important secondary sense of "ornaments of a woman's dress, decoration" (compare kosmokomes "dressing the hair," and cosmetic) as well as "the universe, the world." Pythagoras is said to have been the first to apply this word to "the universe," perhaps originally meaning "the starry firmament," but it later was extended to the whole physical world, including the earth. For specific reference to "the world of people," the classical phrase was he oikoumene (ge) "the inhabited (earth)." Septuagint uses both kosmos and oikoumene.

[neufer]

Not Canadian, but Idaho is just across the border... and that looks like a clump of aspen to me. I'd be happy to be corrected.

Maybe... but aspens usually grow straight and are free of low branches, except when very young. This looks more like a cottonwood stand to me.

paper birch

---

The Province tree of Saskatchewan is the paper birch :

Betula papyrifera (paper birch, also known as (American) white birch and canoe birch) is a short-lived species of birch native to northern North America. Paper birch is named for the tree's thin white bark, which often peels in paper like layers from the trunk. Paper birch is often one of the first species to colonize a burned area within the northern latitudes, and is an important species for moose browsing. The wood is often used for pulpwood and firewood.

[geoffrey.landis]

The featured image captured this cosmic triangle with a series of exposures taken from the same camera over 70 minutes

Wait, what? Objects in the sky move at fifteen degrees an hour. The frame of the picture is maybe five degrees or so. If the picture took seventy minutes to take, nothing in the image at the beginning of the series of exposures was still there at the end except for the ground and trees.

[Chris Peterson]

The featured image captured this cosmic triangle with a series of exposures taken from the same camera over 70 minutes

Wait, what? Objects in the sky move at fifteen degrees an hour. The frame of the picture is maybe five degrees or so. If the picture took seventy minutes to take, nothing in the image at the beginning of the series of exposures was still there at the end except for the ground and trees.

Because when you take images of the sky over many minutes you align the exposures before you stack them.

[geoffrey.landis]

There's no distinct dividing line between a manipulated image and an unmanipulated image-- pretty much all the images have some processing-- but this one could reasonably be more accurately described as "a photo of Venus and the moon at twilight, onto which was photoshopped an image of the Pleiades".

[Chris Peterson]

There's no distinct dividing line between a manipulated image and an unmanipulated image-- pretty much all the images have some processing-- but this one could reasonably be more accurately described as "a photo of Venus and the moon at twilight, onto which was photoshopped an image of the Pleiades".

Well, since it was a single camera, in a single location, with the individual frames shot over a short period of time, it's really nothing more than an example of fancy HDR processing. I don't think your proposed description actually confuses the issue, rather than clarifying it. The image is an accurate representation of reality with nothing adjusted but the dynamic range (which is something that virtually every image does).

[Stephen_India]

It’s beautiful but the scale of the image doesn’t suit my eyes, i mean the wide filed of the foreground and the size of Pleiades in relation to it and with the moon and Venus is odd to me. I might be wrong too.

[Chris Peterson]

It’s beautiful but the scale of the image doesn’t suit my eyes, i mean the wide filed of the foreground and the size of Pleiades in relation to it and with the moon and Venus is odd to me. I might be wrong too.

Everything in the image is consistent with reality. When the image was made, the Moon and Venus were 8.8° apart, and Venus was about 5° from the Pleiades. The Moon is about 0.5° across. All these numbers are consistent with the sizes of the objects in the image and their separation. Using the pixel scale determined by these known factors, and assuming that the tree stand is 30 feet high, we can conclude that the photographer was standing about 500 feet from the trees, which seems perfectly reasonable.

[Shonkin]

Could it be a clump of chokecherries?

[ta152h0]

If you are taking votes, how about a sycamore tree? my wife really likes this picture & said we should get a poster of it. pass the ice cold one

[neufer]

Could it be a clump of chokecherries?

• Can you say "Sacagawea's clump of chokecherries" six times fast?

<<Chokecherry is a suckering shrub or small tree growing to 1–6 m tall. The wild chokecherry is often considered a pest, as it is a host for the tent caterpillar, a threat to other fruit plants. However, there are more appreciated cultivars of the chokecherry. 'Canada Red' or 'Schubert' has leaves that mature to purple and turn orange and red in the autumn. Research at the University of Saskatchewan seeks to find and create new cultivars to increase production and processing. In 2007, Governor John Hoeven signed a bill naming the chokecherry the official fruit of the state of North Dakota, in part because its remains have been found at more archeological sites in the Dakotas than anywhere else. Chokecherry is also used to craft wine in the western United States, mainly in the Dakotas and Utah, as well as in Manitoba, Canada

For many Native American tribes of the Northern Rockies, Northern Plains, and boreal forest region of Canada and the United States, chokecherries are the most important fruit in their traditional diets and are part of pemmican, a staple traditional food. The bark of chokecherry root is made into an asperous-textured concoction used to ward off or treat colds, fever and stomach maladies by Native Americans. The inner bark of the chokecherry, as well as red osier dogwood, or alder, is also used by some tribes in ceremonial smoking mixtures, known as kinnikinnick. The chokecherry fruit can be used to make jam or syrup, but the bitter nature of the fruit requires sugar to sweeten the preserves. Sacagawea was eating choke cherries when she was discovered by Lewis and Clark. The Plains Indians pound up the whole fruits—including the toxic pits—into a mortar, from which they made sun-baked cakes.

Chokecherry is toxic to horses, moose, cattle, goats, deer, and other animals with segmented stomachs (rumens), especially after the leaves have wilted (such as after a frost or after branches have been broken) because wilting releases cyanide and makes the plant sweet. Symptoms of a horse that has been poisoned include heavy breathing, agitation, and weakness..>>

[TheZuke!]

Picking chokecherries was a common activity in my childhood, which lead to chokecherry syrup on pancakes.
(Not to be confused with Choke Berries, a different plant)

Chokecherries were sometimes used in making pemmican.
(A friend once told me, "If you are offered some pemmican, refuse it!" Apparently she had tried some...)

[Ann]

Picking chokecherries was a common activity in my childhood, which lead to chokecherry syrup on pancakes.
(Not to be confused with Choke Berries, a different plant)

Chokecherries were sometimes used in making pemmican.
(A friend once told me, "If you are offered some pemmican, refuse it!" Apparently she had tried some...)

Grape choking hazard. Getty images.

---

Chokecherry or chokegrape?

Ann

[TheZuke!]

Picking chokecherries was a common activity in my childhood, which lead to chokecherry syrup on pancakes.
(Not to be confused with Choke Berries, a different plant)

Chokecherries were sometimes used in making pemmican.
(A friend once told me, "If you are offered some pemmican, refuse it!" Apparently she had tried some...)

Chokecherry or chokegrape?

Ann

After eating a couple handfuls of chokecherries, you may feel a slight dryness and numbness in your mouth, I was told that was a consequence of the cyanide component within the berries. The fruit itself (I've heard) doesn't have the poison, but the pit does. So, probably the sensation in the mouth might be a result of sucking the pits to get the last bit of fruit off them.