Now it is the New Year's Comet - Comet Wirtanen, Orbital Motion, and Diatomic Carbon Gas

Last night I got to try taking pictures of Comet Wirtanen again, with assistance from my son, who mostly wanted to run the "driver's seat" controls on the telescope mounting. When I processed the photos (stacking about a dozen) he noticed the comet was not uniformly green:

I asked my son (a kindergarten student) what he thought of the comet, and he said "two carbon atoms, they stickeded together, then got excited and glowed green, while on the bottom sunlight is just reflecting off the dust atmosphere [tail and coma]. Thank you for visiting my blog entry."

Put another way, the comet doesn't really show a tail in this photo, but the visible coma of the comet is not all made of the same stuff. Diatomic carbon molecules fluoresce green and are largely in the upper half of the comet's atmosphere in this photo.  In the bottom half, there is sunlight being reflected from dust particles (and in fact the nucleus itself) which is much whiter. This dust makes up one of the two tails a typical comet has, the dust tail that drags out behind the comet along the path of the orbit. The gas tail isn't really visible in this photo, but tends to point more or less directly away from the sun and is green in the case of Comet Wirtanen. For a better photo, look at SpaceWeather's comet photo gallery.

While the comet was approaching Earth, the tail seems to have been hiding behind the head of the comet, more or less. Now the geometry has changed rapidly as it sped past Earth, and the dust tail is coming out of hiding. This is a tiny comet that just came close enough to be a relatively easy thing to see - which leads to one of the reasons my stars are short lines instead of points - the comet is what I was tracking, and it is moving, even in the short span of time I needed to take these photos.

SpaceWeather.com is run by a public school teacher out of Bishop, California - the site maintains a collection of photos of interesting things in the sky submitted by folks around the world. This link goes to a movie of the comet moving among the background stars over roughly the same time I was taking my pictures. Comet Movie. This shows another object orbiting the sun moving against the starts as it moves away from Earth.

Christmas Comet - Comet Wirtanen

This was the 46th "periodic" comet discovered. In other words, it is in a stable orbit around the sun. This year it made a remarkably close - meaning several times the distance to the Moon - pass by the Earth. It is a little comet, yet even a little comet can be pretty and bright enough to see when it comes close.

This picture is a stack of 12 photos taken literally by putting my camera on its back on the ground and taking 12 exposures of 5 seconds each, then stacking them. No fancy gear needed, in other words. The comet is circled in the upper left, it is the faint fuzzy blob. Lots of folks have taken vastly better photos - this just happens to be mine. The Pleiades are in the lower center of the photo, and the Andromeda Galaxy in the upper right.

The neat thing about these sort of close-pass comets is that you can watch them move. Not quickly enough for the naked eye, but the comet had moved significantly between sunset and the time I took this picture, near eleven pm, at least it had moved its own diameter against the stars.

When planetary distances are considered, there are relatively few chances we have to watch things other than the moon move this fast.

Preparing Acorn Flour from Acorns

It's that time of year! We've collected a lot of acorns, mostly from the Tanbark Oak (Lithocarpus densiflorus), time to make flour!

If these were their close relatives, chestnuts, the process would be simple: shell, dry, grind. These acorns are full of tannins (the stuff that makes tea brown usually), so a few additional steps are involved.

Key things to keep in mind:

1. Dry the acorns as quickly as easily possible without heating them - we spread them in layers an inch or two deep on screens where there is good dry air circulation for a month or two. Acorns are susceptible to mold if stored moist for very long.

2. Do not heat acorns until you are completely finished with preparation of the edible flour and are preparing the final food item - heating these nuts or their flour early ruins the texture and prevents their "gluten-like" materials from showing their amazing properties.

Here are the steps we follow, in order:

Step 1 - Start with shelling the acorns. I have built power machines for doing this, which are messy and I am still unconvinced they saved any time, net. What I do these days for small batches is simply sit at the table while chatting, watching programs, or sitting by the fireplace, and simply shell them by hand using a basic nut cracker. There are several approaches, cracking at the cap end (the white oval is at this end) seems to work best for me, though others have good success putting the nut longwise into the nut cracker. Experiment and find what works for you. Discard any nuts that are moldy, darkened, contain bugs, or otherwise look "off". The shells and discarded nuts we use as mulch in the garden, they do compost given a bit of time.

Shelled acorns for Tanoak acorns look like this, note that not all acorns will have the papery husks.

Step 2 - Remove the husks. Not all acorns have these, so if you have exposed nut meats right after shelling, skip this part. This step is optional - it doesn't seem to be too much of a problem (or even frankly detectable) if the husks are ground with the nuts, I just do this because if the nuts are dry the husks generally fall off easily and it makes examination of the nuts to see if there are hidden bad spots much easier. If the nuts are dry, the husks are just going to fall off by rubbing handfulls of acorns between your hands. The chaff can then be blown off gently or the nuts picked out of the chaff. Discard any acorns with unusual coloration.

Step 3 - Grind the acorns. We put them in a kitchen blender and cover them with tap water until they are covered. Using a medium speed at first, and a high speed later, we grind the acorns into something with the consistency of a "smoothie".

Step 4 - Leach the acorns. We lay out a set of old towels on a screen (lots of ways to do this), with a relatively smooth and fine weave kitchen towel as the top layer. By using some rolling of the edges of the towels a raised rim can be made that helps keep the acorn paste in the center of the towel. Use a spatula to spread the paste out so it is fairly uniformly thick. This is the acorn cake you will leach. Acorn meal exposed to air will darken slightly, which is not a problem. Shown below is an improvised leaching stack on a plastic garden chair. Note - the towels will be permanently stained by this process.

While there are several ways of leaching acorns, this is our preferred one when we have cold weather and a suitable protected outside place to do the leaching. We put a Dramm Fogg-It seedling nozzle on the end of a hose and aim it from a distance at the cake, so that the mist falls evenly over the entire surface of the acorn cake and slowly flows through. We like this method because it can produce great results overnight, most other methods we have tried take several days in the refrigerator.

Every few hours taste the water dripping out of the bottom of the cloth. If it has no bitterness, the leaching may be done. Taste the wet acorn cake to be sure - it should not be bitter. When this stage is reached the leaching is complete and it is time to dry the acorn cake.

Step 5 - Dry the acorn cake. We allow the wet cake to drip for half an hour, then carefully fold the towel corners over the cake. We take this and compress it between layers of dry, clean, rag towels. You can put a cinder block atop the stack or other weight that doesn't care about getting moist. Let it dewater for an hour or so. If you can still squeeze water out by pinching some between your fingers, it needs another pressing with dry rag towels.

Once this initial dewatering is done, we place it on a warm, dry (not hot!) place and set up a slow fan near it. Leave it on the towel - it will continue to wick water out of the cake and help the drying. When the surface of the cake is dry, fold the towel ontop of it and crush the cake into lumps. The middle should be moist still. Allow the lumps (break into half inch or smaller clumps) to dry to the touch, then crumble them up and repeat until the crumbles are dry. Continue the drying for another few hours just to be certain.

Step 6 - Make "flour". In our case, we just put the dry acorn meal back into the blender and pulse it a few times to make a flour-like powder. This is now ready for use. Store in an airtight container in the freezer until ready to use.

Asking my son what he would like people to know about the process, he replied "when do we get to make acorn chocolate chip cookies?".

Up soon, Acorn Chocolate Chip Cookies!

December Apples: Braeburn, Cripp's Pink, Yellow Newtown Pippin, and McIntosh

In early December the figs and finger limes are finished, the oranges and mandarinquats just starting,  and the apples are in their glory! We are down to four apples still on the trees - and these are the late gems. Yellow Newtown Pippin still hasn't reached it's prime, which usually happens after first frost.

From front right clockwise: McIntosh, Braeburn, Cripp's Pink, Yellow Newtown Pippin.

These are radically distinct apples. Getting them fresh off the tree is a profoundly different experience than getting unknown age apples off a typical store shelf. You certainly can get great apples at the store - I just don't know how to do it reliably. Going over them in that order:

McIntosh - this is our son's favorite. When I give him a choice of these four, he takes the McIntosh and tells me "you can have one of these [meaning any except the McIntosh he by now has bitten]". At this time of year these are tender (not mealy!) apples with amazing aromatics - these are richly fragrant, sweet apples, with deep flavor. This is the National Apple of Canada. For us, this is the fourth heaviest bearing apple tree in the yard. This month is the end of the harvest, they don't always last into December.

Braeburn - this is my favorite of the four. It is a firm apple with a sweet-tart apple flavor. This is the apple tree I planted outside the house back door (alongside Montmorency cherry), so I can have a snack without having to battle the autumn storms! It bears fairly heavily, our third heaviest and a very reliable one. These can hold on tree to the end of the month, generally, though gather them once frost falls.

Cripps Pink - this is in the market as "Pink Lady", though I prefer the older name. The apples are just now coming into their full flavor and sweetness - these are good. The tree bears heavily and the apples have been tasty since late August.

Yellow Newton Pippin - these are astounding! Unlike most US market apples, these have a light russett - the skin is rough in patches. These are firm, sweet-tart, flavorful, and the last apples on our trees generally - we've picked these at their prime still as late as  January (if we haven't eaten them all first...). This is our heaviest bearing and most reliably bearing tree.

Golden Chanterelle Risotto

It's after a mushroom hunting expedition, cool Fall weather just begging for a warm, tasty, filling meal - showing off some of the Golden Chanterelles we found. Risotto is a tradition in our family, right along with Chicken Noodle Soup, despite having no known Italian in our heritage... with that note, this may not even be a proper "risotto", though we enjoy it! (and, in case you cannot tell, I do not depend on food photography for my livelihood...)

Recipe:

1 medium onion, chopped fine
1-2 cups of chopped or sliced Golden Chanterelles
2 tbsp. of olive oil
1.5 cups of Arborio rice
0.5 cup of white wine
5.5 cups of homemade chicken broth (or low sodium commercial broth)
0.5 tsp. of salt
0.5 tsp. of fresh ground black pepper
2 tbsp of fresh chopped celery hearts leaves
0.25 cup grated Parmesan cheese

Start with some Golden Chanterelles, enough when cleaned and diced to make about one to two cups of medium-diced mushrooms (we cut about 1/8" thick and perhaps 1/2" wide and 1" long at most - the thickness matters it seems, the rest is a matter of taste). Wash them (these are fine with being washed), trim off any bits that are imperfect, then dice.

Dice one medium yellow onion finely.

Add enough oil to a large pot to cover the bottom thinly (two tablespoons, more or less).

Add the onions and mushrooms. Apply heat and begin to brown the onions. When the onions are lightly carmelized, the mushrooms ought to be about right.

Add 1.5 cups of Arborio rice and stir to brown the rice, takes one to two minutes. The rice should be semi-transparent and the oil should be largely absorbed by the rice. Grains should be very lightly browned, at least in spots. There is a wide range of browning that is ok, though no need to overdo it - when in doubt, stop early.

Add 0.5 cup of white wine into the pot - there will be a lot of steam. Follow it by 1 cup of hot chicken broth (you need 5.5 cups of low-sodium or homemade broth) and start stirring, being careful to scrape the bottom of the pot often.

Every time the liquid level gets low, add more hot broth and keep stirring. It should take about half an hour on medium-high heat. This dish is an exercise program for your arms!

Once the rice is al-dente (you may not need all the broth, or may need a bit more - water is ok in a pinch), take it off the heat.

Stir in the chopped celery leaves, salt, Parmesan, and black pepper. Allow it to rest for a few minutes off the heat.

Stir once more and serve. Traditionally, more Parmesan is a good topping.

Enjoy!

Fall Mushroom Season in Full Swing

Cantharellus californicus - the Giant Golden California Chanterelle has made its usual appearance under oak trees within the coastal fog belt of Northern California. Today is the first day of December.

Yesterday, we found several under Coastal Live Oaks near sea level - Quercus agrifolia - though they appear under several species of oaks in our area. In our yard they appear under Canyon Live Oaks, Quercus chrysolepis. I am suspicious that they can grow on Tanbark Oaks, yet lack proof.

Please be aware there are poisonous mushrooms that can be mistaken for a Chanterelle, so don't start picking any edible mushrooms based on a book, a photo, or this blog. If you are interested, there is only one safe route to the practical knowledge - join a local mycological society and participate in some of the forays to become familiar with the local practices and rules. We are erratic members of the Mycological Society of San Francisco (mssf.org). Good mycological societies can be found in many cities. While you might expect these societies to be full of scientists, generally there are many different constituencies - a large one of which often includes top local chefs!

This species is the largest chanterelle species in the world. Finding one is often enough for a quality risotto for the whole family (one of our normal ways of fixing them), though they can be sliced and sauteed or fixed any number of ways. Avoid freezing or drying this type of mushroom, the results can be disappointing.

There is joy in finding even just one of these. Asking my son about the one he found, he had this to say "but what about all the poison oak?" - he raises a good point, as Poison Oak often grows under these oaks (it is not an oak, but a low shrub or vine that causes horrible contact rashes, about a day after contact...).

If you do find one, there are tricks to finding more, however! First, stop moving. Stand still and look around - these rarely occur alone, more typically occurring in groups under the dripline of the tree. Second, these often do not push up far above the leaf litter - or at all - so look for low mounds with bits of chanterelle poking out at the edges. Here is what you often see when hunting these in the field:

Consider this our invitation to you to experience the joys of mycology and mushroom hunting!

Putting the "Cloud" back into our "Cloud Forest"

Redwoods only occur in natural foggy-summer areas. This last summer, like several before, has had virtually no fog. Part of our farm is natural second-growth redwood forest. Twenty or so years ago, when I moved here, it was a perpetual race: would the tomatoes ripen, or would the first Fall frost claim them?


Somehow I didn't notice when that period ended, but it was within the last ten years. This year I had a tomato ripen in July!

The beginning of the Fall rainy season brought rain, which I am certain every part of the farm greatly appreciates. More, it brought back the fog - just a layer a little thicker than the trees are tall, with the amazing visuals natural here:

Spraint!

This is one of my favorite almost-never-get-the-chance-to-use-words in English! It refers to otter poo.

Evidently there is an entire science built around the study of spraints as a sort of sideways approach to studying otters - as poo tends not to be motile, while otters are absurdly motile. Just compare the quality of the above photo to the one of the source of the spraint, below, which would make any photographer of Nessie proud for its clarity and definition...

These (or similar) River Otters (Lontra canadensis) leave spraints that we see on every visit to my family in the Sierra Nevada foothills east of Sacramento - but this is only the third time I've seen otters in person on this property.

When asked to talk about spraints, my son said "No!, I'll tell you about cats, ONLY cats. I want to talk about cats right now."

"Sweet" Acorns from Valley Oaks

These are the acorns of our favorite eating (after processing!) oak, the Valley Oak, Quercus lobata. This is often what you see when you look at the ground under a Valley Oak this time of year.

On rare occasions, you see something entirely different - not a total absence of acorns, which could simply indicate a poor crop yield, but a simultaneous abundance of acorn shells and absence or near-absence of intact acorns. If you find yourself walking under a Valley Oak on ground that doesn't look like shown above, rather resembling what is shown below, you may have found a Sweet Acorn Valley Oak. Thank the California Native Americans that were here before the Europeans. This is one of their domesticated crops.

What? Lots and lots of acorn shells, and not a single intact acorn. There must be a reason ... and there is. These are sweet acorns (see last paragraph below), or at least their remains.

"Fall" is the name of the season - sit under an Oak tree if you need a hint as to why it carries that name. In fact, more than a subtle clue to the origins of the name of the season, acorns are incredibly important food. They sustained First Nations populations across much of North America, as well as on many other continents. They still do in many places, and even reach mainstream culture in several modern countries, such as South Korea. We collect and eat acorns in our family, without any known Native American in our genetic heritage.

The importance of Acorns can first be gleaned by noticing that the nut and tree from which the nut arises have different names: the acorn and the oak are on parity with each other as important objects to be able to identify. This is actually quite rare: either the fruit, flower, or tree gets named first and then everything else is named in reference to that first name. A peach is important, it comes from a peach tree. A cashew is important, it comes from a cashew tree. Pine nuts come from Pine trees, and are of "lesser" importance than the wood of that tree. Exceptions are rare: there is the 'ōhi'a tree of Hawai'i, and its flower the Lehua; the Oak tree and the Acorn; I challenge anyone to find more than a handful more examples. When you do, you have found something very important to our history.

There are four types of Oak that are abundant in our general area: Tanbark Oak (actually in the genus Lithocarpus), Valley Oak, Blue Oak, and Canyon Oak. We only have the first and last in our yard, but the others are in the area and in the yards of family and friends.

Valley Oaks are special in several ways: first, their acorns are large and leach easily, so these are fast to collect and quick to prepare. Second, they were domesticated by several tribes of the California Native Americans. With the arrival of Europeans and the wholesale displacement of these folks, many of these plots and forests of domesticated Valley Oaks were lost or forgotten. Many were cut down to clear land for other agriculture, ranching, or just firewood. The displaced people could not simply pick up the trees and relocate - first crops might take twenty years or more from seed planting, supposing the folks displacing the California Native Americans had been nice enough to let them wait to harvest the Fall crop before displacing them.

Fortunately, these are long lived trees and many have survived, or given rise to additional generations of sweet acorns.

What is a sweet acorn? An acorn that does not have the massive amount of tannin that most acorns contain, one that can simply be dried and ground to meal before using. These are roughly comparable to chestnuts, some can even be eaten fresh (get local competent guidance). In our experience, we often give them a quick leaching treatment, as often these are not the original trees, rather their offspring that have been crossed with non-sweet trees, so they have greatly reduced tannin.

There is Ilmenite in them thar hills!

And magnetite! Actually, quite a few heavy minerals. None of which appear to be gold...

This afternoon I and my son tried our hands at panning for gold in the Sierra Nevada foothills of California just east of Sacramento. After a while, we began to understand that there might be some art to this whole "panning for gold" thing.

To start with, pick a stream that actually contains gold.

However, we really weren't looking for gold. We were looking for magnetic sands - my son is intensely interested in magnetism (and mushrooms, and lizards, and many more things). The dark, heavy sands that, in many nearby streams, often indicates you are in the right general area to find gold, in this case indicate that you are in the right general area to find dark, heavy sands.

To many folks, these sands are not interesting.

We are not those folks.

With a small Rare Earth magnet (any decent magnet will work), a plastic bag (magnets rust if they get wet), and a gold pan, we successfully collected many grams of real, genuine, magnetic sand.

First, it is fun to play with with a magnet and is a clean material for field visualization.
Second, it is a neat organic additive to soils low in iron to add that critical mineral as well as potentially other trace minerals to our soils.

Next up: what is the mineralogy of this sand? We'll explore that using some simple tools next.

Stubborn Honey Mushrooms

Our area (the Santa Cruz Mountains) often has rain before the end of October, though not this year. We haven't had real precipitation in six months or more now. What we have had is a tiny amount of fog drip. These are not good conditions for mushroom hunting.

Even so, Armillaria mellea is a determined species. The Honey Mushroom connects to oak trees (admittedly it seems to be a pathogen more often than a symbiont), and is ubiquitous in Western Oak forests this time of year. This connection seems to give it access to water that other local mushrooms cannot access. Here they are fruiting in our yard a few days ago!

Notice that the caps are drying out even as they begin spore production. The cap on the right has cracked from desiccation in the unusually dry Fall air, but these still successfully fruited, pushing through the bark of a fallen tanoak log.

The dry caps were bug-free, even though the stems had some insect damage. I rarely see mature Honey Mushrooms without damage to the caps from bugs.

We're looking forward to the start of the main season with the rains, which may not begin until the start of December!

Maximum Acorn is here!

Stand in the tanoak woods on a warm Autumn evening for the visceral definition of the season's shorter name, "Fall". All around is a percussive symphony of acorns falling through leaf and limb, finally collecting in patches and pockets and piles on the forest floor.

What most people think of as decorations of the season we think of quite differently: food.

Why?


Because when properly prepared, these make a flour as tasty as Chestnut flour. The trick is twofold: dry the acorns without overheating them, then use a slow cold water process to leach out the tannins. More on that in a later post. For now, gather them and spread them in thin layers in dappled sun at most, with good air circulation, for several weeks until the nuts are dry and hard.

We shell them when dried and discard any with problems. The good nuts get dried more in a warm (not hot) air fan. We gather in October and November with drying done by late December most years.

The  abundance of bedrock acorn mortars in our area was my first unsubtle hint that these might be worth the effort. After several false starts, we seem to have this down to a stable process.

In addition to Tanoak (Lithocarpus densiflorus), the Canyon, Valley, and Blue Oaks have excellent acorns - they all get the same treatment.

Brunsvigia pollination time!

Brunsvigia littoralis is an endangered bulb related to Amaryllis from the Cape Province of South Africa. Ours came from the U.C. Berkeley Botanical Garden fall plant sale years ago (more than a decade...). While habitat destruction is an important cause of this plant's endangerment, it has another problem: it is pollinated only by the longer-billed Malachite Sunbird (Nectarinia famosa). These birds perch on the flower stems and reach into the flowers for nectar, providing effective pollination. Malachite Sunbirds do not like disturbed habitats and areas altered by people, and are not known from California regardless. What is a plant to do?

Enter the local stand-in for Malachite Sunbirds: our son.

He has been pollinating these since he was two and saw me doing it. He is also the hand pollinator for pretty much everything he can reach this time of year - we grow several Haemanthus species as well as some other South African bulbs far from their native pollinators. He is great at it. Without hand pollination, we typically get one or two seeds per flowerhead. With hand pollination, we get thirty or more.

In his words: "I'm not going to tell you". OK, perhaps he is protective of his methods. However, the basic game is getting the pollen from the anthers (where the yellow powder of pollen is made) to the stigma when it is able to accept pollen (the tip gets fuzzy and white). If the pollen gets where it needs to be at the right time, each flower can produce two to six seeds.

These are not plants for impatient folks. From seed to flowering can easily be more than a decade. The bulbs are larger than footballs (American type) when ready to flower. They are worth the wait! In California they tend to flower in September, before the leaves emerge from the dry late summer soil for their fall and winter growth period.

The Fall Apples Begin: Greensleeves

This year we are beginning to harvest the Fall fruit - Apples figure large in that process. We have the first fruiting of three trees this year - White Pearmain, Honeycrisp, and Greensleeves.

When buying apples at the store, they barely resemble their homegrown kin. I very much enjoy these apples - nevermore than when picked in fully ripe perfection straight off the tree. Honeycrisp was startlingly sweet, crunchy, and phenomonal. Perhaps it was even more so because I regularly eat this one bought from the supermarket, which sets a certain basis for comparison.

An apple I had no basis for comparison with is Greensleeves. Indeed, after reading it's description, I had to simply find and buy a grafted tree, plant it, and wait. This is the tenth year of that process... and it was worth the wait.

Greensleeves is a firm, smooth, sweet and tart apple with a great flavor. It is a yellowish apple of medium size.