The Earth Story

Cool Coccolithophores! Coccolithophores are one celled organisms, a type of phytoplankton that live in the ocean. They have been around for millions of years! These organisms cover themselves with tiny circular plates made of calcite and reproduce asexually. They are the leading calcite producers in our ocean, dumping more than 1.5 million tons per year. -KK1 https://flic.kr/p/bww7Mg https://earthobservatory.nasa.gov/features/Coccolithophores/coccolith_1.php https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/coccolithophore

Rapeseed petal Ever wondered what the beautiful flowers we all enjoy in our gardens look like at high magnification? This photo shows the petals of a yellow rapeseed (aka colza) flower viewed in a scanning electron microscope. Loz Image credit: Oliver Meckes/Nicole Ottawa/Eye of Science

Stratigralicious!

This is pretty awesome. The Great Lakes in North America are apparently a tough place to do stratigraphy. Geologists would love to be able to take cores through these lakes and say how the chemistry of those lakes changed over time, but using those lake records requires knowing how old the layers are. There is a lot of reworking of carbon in the sediments, preventing Carbon-14 dating from being used to date any specific layer, so scientists led by researchers at the Large Lakes Observatory at the University of Minnesota Duluth went looking for something else they could use to date an individual layer, and they found this.

The scientists pulled these tiny chips from a core near Isle Royale in Lake Superior. These shards of rock, seen zoomed in under an electron microscope, are igneous. You can see the sharp edges of broken bubbles, ruptured in a volcanic explosion. They analyzed the chemistry and found that these match the eruption products of the Mount Mazama blast 7600 years ago, the eruption that led to the formation of Crater Lake.

The Scientists now know that they can use the presence of these ash layers to date other sedimentary cores in the Great Lakes. Beyond that, here’s ash from a volcano on the other side of the continent dropped into the Great Lakes and still trapped there today, and I think that’s kinda cool!

-JBB

Image credit and original paper, Spano et al., 2017 http://bit.ly/2C7aIgt

Your Shades of Blue Look Splendens

The male peacock spider is quite literally the itsy-bitsy little spider, only about four millimeters long. No matter their size, these guys have bright colored patterns covering their bodies, used for visual communication and gaining the attention of females.

Maratus splendens uses two different mechanisms to create the hues that appear on the spider’s modified hairs. One way uses pigments, just as humans and flowers do, in order to produce the reds, whites and creams on the spider. The blue appearing on this arachnid is produced by very tiny nanostructures that reflect light of a particular wavelength. These structures are embedded in flat, convex scales which amplify the light reflections. Structural color has been well documented in many species, though it is still much less common than pigment coloration.

“We’ve known for some time that butterflies and moths are doing all sorts of really clever things with manipulating the behavior of light with their scales. What we’re discovering with this study and others is that spiders, which are obviously a very different group of animals, are also playing with light,” stated Nathan Morehouse from the University of Pittsburgh.

Unlike pigments that fade over a period of time, undamaged structural color will not. This is why insects and birds held in museums keep their sheen after so many years. It seems that the majority of creatures produce their blue shades by using structural color rather than with pigments. This does not apply to plants as they easily make blue pigments.

Lead author Doekele Stavenga, professor at the University of Groningen, explains, "The special photonic invention of the Maratus splendens scales is the insertion of two layers of extremely fine threads or filaments that subtly tune the refractive index profile of the multilayers, thus creating the distinct blue color.” Stavenga and a team of researchers used a range of techniques including a scanning electron microscope (SEM) to study the spider’s colors in depth. They discovered that these blue colors are not only structural, but some other type that has never been described before.

So, can female Maratus even see the brilliant colors their suitors flash for their appreciation-or lack of? “We have very good evidence that these animals can see these colors. It would be no surprise for them to see blue but the twist is that they can see, well, we think they can see, the red,” Morehouse says. This would make this species a bit odd among arachnids since many are not known for having good color vision. If the females can interpret the differences between shades of color, then they ought to be able to pick out superior male designs as well.

To think, all of that happening within the teeny tiny ecosystems of these wee spiders. Life really is complex, no matter how small.

--Mi

Image Credit – http://bit.ly/2biOAW0 http://bit.ly/2btGiI8

Source – http://bit.ly/2bihnas

Hermit History

Hermit crabs are crustaceans with a soft, spiral-shaped abdomen which can fit into a mollusk shell. They borrow these shells as their mobile home and use them for protection from predation and water retention when on land. Modern hermit crabs prefer marine snail shells, competing for the most protective specimens of the right size. They even use unusual items such as glass bottles and soft drink cans in a pinch. Despite their antisocial name, hermit crabs have a long and diverse family tree.

Hermit crabs are known in the fossil record as far back as the Early Jurassic. Though few directly preserved exoskeletons have been found, they leave traces in the alterations they commonly make to their shells. These include scratches to the surface caused as they appraise their potential home before they move in, organisms that they encourage to live on their shells for defense, and transport of marine shells to inland environments. Terrestrial crabs have evolved the ability to breathe air and can travel miles inland if they have enough access to water.

Hermit crabs in the time of the dinosaurs used ammonite shells as their homes. Ammonites were shelled cephalopods (related to octopus and squid) and were some of the most plentiful shell-building organisms of the Cretaceous period. Hermit crabs would have had easy access to these armored, coiled shells as second-hand homes. The attached picture shows a crab's claw poking out of the opening of an ammonite shell. Since the extinction of the ammonites alongside the dinosaurs in the end-Cretaceous extinction 65 million years ago, surviving hermit crabs have evolved to exclusively use snail shells for protection.

Some hermits even “carcinized,” or evolved into more conventional crab body types. The giant Alaskan king crab, famed for its tasty leg meat, is believed to have evolved from hermit crabs that gave up their shells. The asymmetrical shape of its exoskeleton provides a subtle hint of the spiral shaped abdomen of its ancestors.

-DK

Pictures from: http://bit.ly/1spvbrb (PDF) http://bit.ly/1spuNJe Other sources: http://bit.ly/1WXzuGp http://bit.ly/25zoGUb

RIME, AND REASON

You may be familiar with the common six-sided dendritic snowflake shape, but do you know about other ice crystal shapes and how they form? Ice crystals take on a hexagonal shape due to the internal structure of the water molecules. The weak hydrogen bonds of solid water molecules results in a 6-fold rotational symmetry (360°/6, or 60°). However, ice crystals forming in different temperatures and areas with different moisture content take on various hexagonal shapes, including plates, columns, needles, and stars.

Snow crystals tend to form simpler shapes when humidity is low and more complex shapes as humidity increases. As snow crystals are transported through a cloud, they move through areas with different temperature and humidity levels. Since no two ice crystals follow the exact same trajectory, nor contain the exact same number of water molecules, it is EXTREMELY unlikely that any two snowflakes will be identical.

This photograph of a single capped column snowflake was taken with a Low Temperature Scanning Electron Microscope (LT-SEM). This snowflake began its journey in an area of a cloud that favored columns (-5°C to -15°C, or -30°C and below), then was transported to an area more favorable to plate growth which resulted in caps at each end. As the snowflake fell through the atmosphere, it came into contact with extremely tiny (about 10 μm) supercooled liquid water droplets. These tiny water droplets froze to the surface of the ice crystal, giving it a fuzzy appearance, called riming. The LT-SEM can resolve these tiny snowflake features that would not normally be visible using a light microscope.

So, how are these snowflakes captured and prepared for the LT-SEM? The snow is collected using cooled copper plates that contain a methyl cellulose solution. The plates are quickly dumped into liquid nitrogen which cools them to around -196C and allows for safe transport. Finally, they are coated with platinum to make them electrically conductive for the LT-SEM imaging.

-Amy

For more LT-SEM snowflake images: http://emu.arsusda.gov/snowsite/default.html

Snow Crystal Classification: http://tinyurl.com/d8pk3t5 http://tinyurl.com/c9lqe6f

Additional References: http://www.its.caltech.edu/~atomic/publist/rpp5_4_R03.pdf http://www.its.caltech.edu/~atomic/snowcrystals/primer/primer.htm http://www.storyofsnow.com/blog1.php/2011/03/15/how-the-crystal-got-its-six

Image credit: Electron and Confocal Microscopy Laboratory, Agricultural Research Service, U. S. Department of Agriculture

"Shut up and take my money."

Yeah, if you've got a "Lego" account, give that a vote? 

Surreal life An amazing false colour photo of the stamens of a hibiscus flower, with attached grains of spiky pollen. The image was taken using a scanning electron microscope by a German team who like to mix science and artistic beauty. Loz Image credit: Eye of Science For more great photos visit http://www.eyeofscience.de/en/

NEW PRIMITIVE MINERALS DISCOVERED WITHIN METEORITE A new mineral, a titania named panguite, was found within the Allende meteorite using a scanning electron microscope. The International Mineralogical Association’s Commission on New Minerals, Nomenclature, and Classification has approved the new mineral and its name. The Allende meteorite fell to Earth in Mexico in 1969 and through nanomineralogy investigations has yielded the discovery of 9 new minerals including panguite by geologist Chi Ma of the California Institute of Technology (Caltech), USA. The name panguite is a reference to Pan Gu, a giant from Chinese mythology who created the world by separating the heaven and earth from chaos in the beginning. Panguite, along with the minerals kangite, tistarite and allendeite, was one of the first solid materials to form in our solar system, about 4.567 billion years ago. The mineral’s chemical name is (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3; it contains oxygen, magnesium, aluminium, titanium, calcium, scandium and zirconium. The presence of zirconium in particular will aid scientists in discovering more about the environment before and after the solar system’s formation. Panguite was first observed under a scanning electron microscope in an ultra-refractory inclusion embedded in the meteorite. The term refractory here means that these inclusions contain minerals that are stable at high temperatures and in extreme environments; therefore more likely to have formed as primitive, high-temperature liquids produced by the solar nebula. The Allende meteorite is the largest carbonaceous chondrite ever found on Earth and is very well studied. The image is an enlarged backscatter image showing the area where panguite crystals occur with smaller Zr-rich panguite in davisite. Davisite, CaScAlSiO_6, is a new member of the Ca clinopyroxene group, from the Allende meteorite. The mottled appearance of the davisite mostly reflects differences in Sc concentrations. -TEL http://www.wired.com/wiredscience/2012/06/new-mineral-panguite/; http://mr.caltech.edu/press_releases/13524; http://ammin.geoscienceworld.org/content/97/7/1219.full?ijkey=G2n1UMXmu7r4.&keytype=ref&siteid=gsammin

This is a false coloured image of pollen from different plant species taken with a Scanning Electron Microscope (SEM). Pollen is a minute mass of microspores that are produced in seed plants. These tiny grains are formed in the anther of a male plant and are subsequently transported via wind, water or insects etc to the pistil of a female plant, where fertilisation occurs. Pollen grains may be small, but they are mighty. The outer layer, known as the exine is highly resistant to degeneration and can even withhold intense heat as well as concentrated acids and bases. Pollen, for all its beauty and functionality, is the bane of many peoples Spring and Summer. It is produced in such quantities that pollen is actually a significant component of the Earth’s atmosphere and the proteinaceous substance in many pollen grains induces an allergic reaction commonly known as hay fever. Hay fever occurs when the immune system mistakes this harmless airborne substance as a threat. As your body thinks the substance is harmful it produces an antibody called immunoglobulin E to attack it. It then releases the chemical histamine which causes cold like symptoms in the individual. It is estimated that about 20% of people in Western Europe and North America suffer from some degree of hay fever; all thanks to these little guys. But, of course, a few runny noses and teary eyes is worth the vital job that pollen grains do. Aaaachoo! -Jean Image courtesy of Alex Hyde.

Rapeseed petal Ever wondered what the beautiful flowers we all enjoy in our gardens look like at high magnification? This photo shows the petals of a yellow rapeseed (aka colza) flower viewed in a scanning electron microscope. Loz Image credit: Oliver Meckes/Nicole Ottawa/Eye of Science