суббота, 16 ноября 2019 г.

2019 November 14 Mercury and the Quiet Sun Image Credit &...



2019 November 14

Mercury and the Quiet Sun
Image Credit & Copyright: John Chumack

Explanation: On November 11, 2019 the Sun was mostly quiet, experiencing a minimum in its 11 year cycle of activity. In fact, the only spot visible was actually planet Mercury, making a leisurely 5 ½ hour transit in front of the calm solar disk. About 1/200th the apparent diameter of the Sun, the silhouette of the solar system’s inner most planet is near center in this sharp, full Sun snapshot. Taken with a hydrogen alpha filter and safe solar telescope, the image also captures prominences around the solar limb, the glowing plasma trapped in arcing magnetic fields. Of course, only inner planets Mercury and Venus can transit the Sun to appear in silhouette when viewed from planet Earth. Following its transit in 2016, this was Mercury’s 4th of 14 transits across the solar disk in the 21st century. The next transit of Mercury will be on November 13, 2032.

∞ Source: apod.nasa.gov/apod/ap191114.html



* This article was originally published here

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa


In the ninth to seventh centuries B.C., the Assyrians, based in northern Mesopotamia (modern Iraq), forged a great empire that extended at its height from Egypt, Syria, Lebanon, Israel, Jordan, and parts of Turkey in the west, through Iraq to the mountains of Iran and Armenia in the east. To glorify their reigns, the Assyrian rulers built majestic palaces adorned with relief sculptures that portray the king as a mighty warrior and hunter, and confront visitors with imposing images of winged bulls, demons and other mythological guardians.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
Royal Lion Hunt, 875 - 860 BC, British Museum [1849,1222.8]
[Credit: © The Trustees of the British Museum]
Assyria: Palace Art of Ancient Iraq, on view at the Getty Villa October 2, 2019 to September 5, 2022, presents a selection of these famous relief sculptures as a special loan from the British Museum in London. Among the greatest masterpieces of Mesopotamian art, the Assyrian reliefs have, since their discovery in the mid-19th century, fascinated viewers with their vivid depictions of warfare, hunting, building works, mythology, rituals, banqueting and other aspects of Assyrian court life. Often bearing cuneiform inscriptions, some scenes show characters, events and places known from the Old Testament and ancient Greek authors. Together they represent the richest body of narrative art and iconography to have survived from the ancient Near East.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
The Banquet Scene, 645-635 BC, British Museum [1856,0909.53]
[Credit: © The Trustees of the British Museum]


“The British Museum possesses the largest and most important collection of Assyrian reliefs in the world. The fourteen panels on view at the Getty Villa create a compelling overview of the subjects, styles, and artistic achievements of Assyria’s sculptors, including outstanding masterpieces such as the ‘Banquet Scene’ of the last great king of Assyria, Ashurbanipal, reviled as ‘Sardanapalus’ in the Old Testament,” says Timothy Potts, director of the J. Paul Getty Museum.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
The Garden of Ashurbanipal, 645 - 635 BC, British Museum [1856, 0909.56]
[Credit: © The Trustees of the British Museum]
“At the time of their discovery, taste in Britain—and Europe generally—hewed strongly to classical models, by which standard some saw these Assyrian monuments as unrefined; but this attitude soon subsided, and they are now universally appreciated as artistic achievements of great visual and emotional power. In our own day the historical and cultural importance of these sculptures has increased with the tragic destruction by ISIS of many of the reliefs that remained in Iraq.  We hope therefore that this display will raise awareness of the need to protect major heritage sites that remain at peril around the world.”

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
Attack on an Enemy Town, 730 - 727 BC, British Museum [1880,0130.7 and 1848,1104.4]
[Credit: © The Trustees of the British Museum]
The Assyrian heartland lay astride the Tigris River in Mesopotamia, in what is today northern Iraq. The reliefs in this exhibition come from the palaces of kings Ashurnasirpal II (883–859 B.C.) and Tiglath-pileser III (745–727 B.C.) at Kalhu (Nimrud), Sargon II (722–705 B.C.) at Dur-Sharrukin (Khorsabad), and the last great Assyrian king Ashurbanipal (668–627 B.C.) at Nineveh.


In the mid-eighth century B.C. the Assyrian Empire expanded westward to the eastern shore of the Mediterranean and Egypt, coming into contact with the Greeks in Phoenicia, on Cyprus, and along the southern coast of Anatolia (Turkey), as well as in trading colonies in northern Syria.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
Camel Rider, 728 BC, British Museum [1849,1222.11]
[Credit: © The Trustees of the British Museum]
Assyrian palaces were imposing complexes that served both as residences for kings and their families and as the venues for official diplomatic and ceremonial functions. The most important rooms within the palaces were decorated with reliefs. Scenes in the throne room and reception halls typically emphasized the king’s military prowess and his status as the all-powerful ruler, sometimes in graphically brutal terms. The king’s private quarters could include beneficent mythological creatures, rituals, and other themes. The hunt was one of the most frequently depicted royal activities, symbolizing the king’s supreme power over the most fearsome enemies.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
Celebration after a Bull Hunt, 875 - 860 BC, British Museum [1849,1222.18]
[Credit: © The Trustees of the British Museum]


The British adventurer Sir Austen Henry Layard (1817-1894), who led the excavations at Nineveh and Kalhu (modern Nimrud), published two series of folio-sized illustrations documenting his discoveries under the title The Monuments of Nineveh (1849-1853). Both series are on display in the exhibition, the complete sets of images being accessible on an iPad in the gallery. A number of reliefs on view in the exhibition were excavated by Layard in 1845-51.

'Assyria: Palace Art of Ancient Iraq' at the Getty Villa
Head of a Bearded Man, 710 - 705 BC, British Museum [1847,0702.11]
[Credit: © The Trustees of the British Museum]
This is the second long-term loan exhibition in the gallery devoted to The Classical World in Context, a new gallery at the Getty Villa highlighting cultures that influenced and interacted with the classical world of ancient Greece and Rome.

The exhibition will remain on view for three years, during which it will coincide with upcoming exhibitions on ancient Mesopotamia (March 18 – July 27, 2020), drawn from the collections of the Musee du Louvre, and ancient Persia’s relationship with the classical world (2021).

Assyria: Palace Art of Ancient Iraq is curated by Timothy Potts, director at the J. Paul Getty Museum, with assistance from Sara E. Cole, assistant curator of antiquities at the J. Paul Getty Museum.

Source: J. Paul Getty Museum [September 10, 2019]



* This article was originally published here

16.10.2019, 18:57:30 UTC - Meteor over Southern Germany

3871 views   14 likes   0 dislikes  

Channel: OGVT - Observatoire géophysique, Val Terbi  

Recorded in Montsevelier (Val Terbi), Jura

Video length: 0:11
Category: Science & Technology
7 comments

Lightning in Slow Motion 1,500 FPS HD


Milliseconds  Lightning in Slow Motion - 1,500 FPS HD

VIDEO prise sur Grenoble ( France ) le 11/11/2019

Vidéo que j'ai prise en sortant de la foire de Grenoble Alpexpo le 11/11/2019 a 17h52

2019 November 15 M16 and the Eagle Nebula Image Credit &...



2019 November 15

M16 and the Eagle Nebula
Image Credit & Copyright: Martin Pugh

Explanation: A star cluster around 2 million years young surrounded by natal clouds of dust and glowing gas, M16 is also known as The Eagle Nebula. This beautifully detailed portrait of the region was made with groundbased narrow and broadband image data. It includes cosmic sculptures made famous in Hubble Space Telescope close-ups of the starforming complex. Described as elephant trunks or Pillars of Creation, dense, dusty columns rising near the center are light-years in length but are gravitationally contracting to form stars. Energetic radiation from the cluster stars erodes material near the tips, eventually exposing the embedded new stars. Extending from the ridge of bright emission at lower left is another dusty starforming column known as the Fairy of Eagle Nebula. M16 lies about 7,000 light-years away, an easy target for binoculars or small telescopes in a nebula rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake).

∞ Source: apod.nasa.gov/apod/ap191115.html



* This article was originally published here

'Cyprus: A Dynamic Island' at the National Museum of Antiquities of the Netherlands


On 11 October 2019, the exhibition Cyprus: A Dynamic Island opened at the Rijksmuseum van Oudheden in Leiden (RMO, the National Museum of Antiquities of the Netherlands). This is a unique exhibition about one of the most important crossroads of ancient cultures in the Mediterranean region. It features a selection of 400 superb archaeological objects, more than 300 of which come from Cyprus’s national collections. They represent over 9,000 years of the island’s history, in an impressive setting of huge artistic landscape photographs. The exhibits include life-sized sculptures and portraits in marble and terracotta, imaginative pottery decorated with little faces and animal figures, luxury imported goods from the Near East and Egypt, large bronze cauldrons and weapons, colourful mosaics, gold jewellery and a royal throne inlaid with silver display, highlighting both the diversity and the uniqueness of the island’s culture. This is the first major exhibition on the archaeology of Cyprus to be shown in the Netherlands. Cyprus: A Dynamic Island will be on view until 15 March 2020, including Mondays.

'Cyprus: A Dynamic Island' at the National Museum of Antiquities of the Netherlands

Cyprus is associated with Aphrodite, the Greek goddess of love who was born ‘from the silver foam of the sea’ near the Cypriot coast. Thanks to its strategic location, the island has been at the centre of contacts and trade between different cultures in the eastern and western Mediterranean for thousands of years. That constant dynamic movement of people, goods and ideas between Cyprus and the surrounding cultures, and the merging of cultural influences are the key emphases in the exhibition. Sea, landscape and the natural beauty of Cyprus features prominently: metres-high artistic photographs of the natural scenery and subtly-moving projections provide the decor for the exhibition’s story. Visitor will experience the exhibition as a relaxed stroll through a serene landscape, passing highlights of Cypriot culture. A second storyline, that of remarkable historical figures and archaeological excavations on Cyprus since the early 19th century, also focuses on illegal digs and trade in antiquities, a subject that remains high on the Cypriot agenda.


Never before has Cyprus lent so many archaeological objects at once to a foreign museum. Loans have been provided by Department of Antiquities in Cyprus from the Cyprus Museum (Nicosia) and diverse other national, regional, and private Cypriot museums. A life-size terracotta grave statue from the famous sanctuary of Ayia Irini will be provided on loan to the RMO by the Swedish National Museums of World Culture. Princessehof Ceramics Museum in Leeuwarden and the Kunstmuseum The Hague contributed ceramic work by Pablo Picasso, who clearly drew inspiration from archaeological pottery. From Museum Voorlinden the RMO was able to obtain the loan of a present-day Venus (‘Venus Bleue’ by Yves Klein). Other objects come from the RMO’s own collection and from the Allard Pierson in Amsterdam.


The exhibition is accompanied by audio guides (Dutch/English), a book for the general public (150 pp., Dutch/English), series of lectures by Dutch and international experts, guided tours (also for families), workshops, and an afternoon seminar organised in conjunction with Leiden University. There will also be a special audio guide for children and special children’s activities in the school holidays.

The exhibition Cyprus: A Dynamic Island and the accompanying book were prepared in close partnership with the Department of Antiquities in Cyprus (Ministry of Transport, Communications and Works) and the Cyprus Museum in Nicosia, and with the support of the A.G. Leventis Foundation; the Embassy of the Republic of Cyprus in the Netherlands; Cyprus Ministry of Tourism; Press and Information Office, Republic of Cyprus; the Prince Bernhard Culture Fund; Labrys Reizen; the Cultural Heritage Agency (Ministry of Education, Culture and Science); and the Society of Corporate Friends of the Rijksmuseum van Oudheden. The Rijksmuseum van Oudheden is supported by the BankGiro Lottery.

Source: Rijksmuseum van Oudheden in Leiden [September 20, 2019]



* This article was originally published here

Tic-Tac & the Triangular shaped UFO's

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Channel: Terry's Theories  

Where do the Tic-Tac and the Triangular shaped UFOs come from. Many people believe that these crafts are from some distant planet. Well not me. I believe these sightings that have been seen all over the country and the world are made by man. I believe someone or some black budget project corporation has been working on these craft and maybe others in the shadows, and now we are starting to see more of them and getting get warmed up to the idea that theses crafts are real and that they are ours maybe even part of this Space Force that we hear whispers of. I Feel one day soon the hole truth will be revealed to us.
Source Video: Professor Simon Holland https://www.youtube.com/watch?v=_lml2D4eHbQ&t=6s

Video length: 17:46
Category: Science & Technology
22 comments

2019 November 16 The Star Streams of NGC 5907 Image Credit...



2019 November 16

The Star Streams of NGC 5907
Image Credit & Copyright: R Jay Gabany (Blackbird Observatory) - collaboration; D.Martinez-Delgado(IAC, MPIA),
J.Penarrubia (U.Victoria) I. Trujillo (IAC) S.Majewski (U.Virginia), M.Pohlen (Cardiff)

Explanation: Grand tidal streams of stars seem to surround galaxy NGC 5907. The arcing structures form tenuous loops extending more than 150,000 light-years from the narrow, edge-on spiral, also known as the Splinter or Knife Edge Galaxy. Recorded only in very deep exposures, the streams likely represent the ghostly trail of a dwarf galaxy - debris left along the orbit of a smaller satellite galaxy that was gradually torn apart and merged with NGC 5907 over four billion years ago. Ultimately this remarkable discovery image, from a small robotic observatory in New Mexico, supports the cosmological scenario in which large spiral galaxies, including our own Milky Way, were formed by the accretion of smaller ones. NGC 5907 lies about 40 million light-years distant in the northern constellation Draco.

∞ Source: apod.nasa.gov/apod/ap191116.html



* This article was originally published here

Prehistoric Carved Stone Grave Item, Dumfries Museum, Scotland, November 2019.

Prehistoric Carved Stone Grave Item, Dumfries Museum, Scotland, November 2019.



* This article was originally published here

'A Wonder to Behold: Craftsmanship and the Creation of Babylon’s Ishtar Gate' at The Institute for the Study of the Ancient World, NY


The Institute for the Study of the Ancient World presents A Wonder to Behold: Craftsmanship and the Creation of Babylon’s Ishtar Gate, opening new avenues for understanding one of the most spectacular achievements of the ancient world. On view from November 6, 2019, through May 24, 2020, the exhibition features 180 objects that bring to life the synthesis of masterful craftsmanship and ancient beliefs that transformed clay, minerals, and organic materials—seen as magically potent substances—into this powerful monument.

'A Wonder to Behold: Craftsmanship and the Creation of Babylon’s Ishtar Gate' at The Institute for the Study of the Ancient World, NY
Reconstructed panel of bricks with a striding lion Neo-Babylonian Period; Processional Way,
El-Kasr Mound, Babylon, Iraq [Credit: The Metropolitan Museum of Art]
A Wonder to Behold demonstrates how the master craftspeople who designed and built the Ishtar Gate and its affiliated Processional Way were not simply skilled technicians—though they were certainly that— but also artists, historians, and ritual practitioners known as “experts” (ummanu). They were believed capable of creating artworks that manifested divine powers on Earth, and the Ishtar Gate, offering entry into the imperial city of Babylon, was designed to be one such magically activated monument.

A Wonder to Behold has been organized by ISAW and co-curated by its Associate Director of Exhibitions and Gallery Curator, Clare Fitzgerald, PhD, with guest curators Anastasia Amrhein, an art historian specializing in the ancient Middle East (University of Pennsylvania), and Elizabeth Knott, PhD, a historian specializing in the textual and visual remains of the ancient Middle East (NYU).

Dr. Fitzgerald states, “ISAW is thrilled to present A Wonder to Behold, which follows the transformation of commonplace, if sacred, materials as they journey from the brickyards to one of the greatest monuments of the ancient world, a divinely protected and ritualized entryway to the inner city of Babylon. In so doing, the exhibition opens a window onto both ancient beliefs and superb artistic skills, and expands our understanding of the critical role of craftspeople in the ancient Middle East. ISAW is grateful to Anastasia Amrhein and Elizabeth Knott, who have brought their deep knowledge to this exhibition.”


Built over the course of King Nebuchadnezzar II’s reign (r. 604–562 BCE), the Ishtar Gate (named in honor of the Mesopotamian goddess Ishtar) was at the epicenter of a major empire that extended from presentday Iran to Egypt. In its final and most spectacular phase, the monument was built with brilliantly glazed bricks, molded in relief to depict hundreds of dragons, lions, and bulls—all set against a background the color of lapis lazuli. At once providing access to and protecting the heart of the sacred imperial city, these creatures inspired both admiration and apprehension.

By the late 19th century, it appeared that all that was left of the Gate were glittering fragments of colorful glazed brick scattered among the rubble of collapsed clay architecture. But between 1899 and 1917, German-led excavations not only studied the glazed remains of the towering Ishtar Gate, but also excavated its molded (unglazed) foundations, which extended deep into the earth. Archaeologist Robert Koldewey sent almost 800 crates of fragments to Berlin, with the permission of the Ottoman, and later the Iraqi governments. Once there, the colorful remains were cleaned, stabilized, and sorted, then assembled piece by piece, creating first whole bricks and subsequently panels of brightly colored raised-relief beasts. These reconstructed ancient remains were joined with modern blue bricks to create a monumental reconstruction (albeit at a slightly smaller scale) of the Ishtar Gate and its affiliated Processional Way at Berlin’s Vorderasiatisches Collection, housed in the Pergamon Museum.

Today, a multi-national process of excavation, reconstruction, and conservation of the Ishtar Gate continues, both on-site and at various institutions. The monument may be experienced not only in Berlin, but also at Babylon, Iraq—now a UNESCO World Heritage Site—where earlier phases of the Gate still stand and visitors can experience its true scale and relationship to the ancient city.


The objects on view in A Wonder to Behold are on loan from a variety of international and domestic collections including the Louvre, the British Museum, the Metropolitan Museum of Art, and, notably, the Vorderasiatisches Museum. Together, they provide a vivid picture of the making of the Ishtar Gate, shedding light on the people who created it and the materials they engaged with and transformed.

The exhibition opens with an introduction to the gateway as revealed through its discovery and reconstruction. A variety of archival drawings, photographs, and objects demonstrate the immense complexity of this undertaking. A 1901 watercolor by archaeologist Walter Andrae, for example, shows the Babylonian system of fitters’ marks that he deciphered, revealing the painstaking process through which the monument was created. This process began by marking out the design on a wall of unadorned bricks, and continued with the molding, glazing, and baking of each individual brick before fitting them together, a task that is something like designing and assembling an intricate puzzle.

The Ishtar Gate and Processional Way represent the epitome of major developments in molding and glazing technologies that had taken place over the preceding centuries, enlivening architecture by bringing color and dimension to otherwise unadorned mud brick buildings. A reconstructed panel on view here shows one of the 120 molded and glazed lions that paraded out from the Gate and down the Processional Way. Believed to be powerful beings associated with the king’s role as protector of his people, the beasts are depicted in bold relief, projecting into the space of the viewer as they intimidated unwelcome visitors while protecting the inhabitants of the city.


Other objects illustrate the links between the world of the gods and the Ishtar Gate through an exploration of the religious meaning of lions, bulls, and mushussu-dragons. These include an Assyro-Babylonian cylinder seal showing the fierce goddess Ishtar, who helped protect the city from enemies, with her lion, and a marble bowl dating from 2900–2600 BCE that demonstrates the continuity and ritual significance of the repeating bull image—which also appears on the facade of the Ishtar Gate—and its ritual significance, already understood to be ancient in Nebuchadnezzar II’s time.

The material components of the Ishtar Gate and Processional Way—clay and a glass-like glaze composed of ground stones and metal oxides—were endowed with metaphysical and magical qualities. The exhibition examines these substances, including their origins, sometimes in far-flung places; the techniques with which they were produced and worked; and the powerful cultural and religious beliefs attached to them.

Endowed with vital power in the ancient Middle East, clay was viewed as the stuff of creation and tied closely to the gods: ancient texts asserted that the first gods and first humans were created of clay. Clay was often used to create figures believed to be imbued with life and capable of acting on their creator’s behalf. As highlighted by a mold for a female figurine here, artists in the ancient Middle East did not share the modern emphasis on the new, but frequently replicated more or less identical images, each thought to be as powerful as the next. As such, molds like this one were understood as authoritative image sources, originally passed down to humanity from the gods.


A Wonder to Behold also includes a fragment of a baked clay plaque with a striding lion reminiscent of those on the Processional Way. This piece, which dates from late 3rd–early 2nd millennium BCE, shows the longevity of lion imagery created from molded clay. Figures like these, which were believed to be capable of effecting change in the lived world, were not restricted to monumental or public contexts, but could also be found in domestic houses and shrines. Although their exact purpose is unknown, they may have protected the household from dangers such as illness and misfortune, as well as from demons, or they may have been directed to perform more specific magical tasks.

A brick from Babylon containing the cuneiform inscription of Nebuchadnezzar II illustrates clay’s inherent malleability and receptivity to touch. After being molded, bricks like these, which were used in official constructions, were stamped with the king’s inscription and laid out to dry in the sun or sometimes baked in a kiln. While this brick was still soft, it was also impressed with the paw of a wandering dog—a humble, everyday touch that gives us a direct, affective point of access to the ancient world.

A cuneiform tablet from the Middle Babylonian Period (ca. 1300–1200 BCE) records a recipe for making red glass that highlights the secret alchemical knowledge of ancient Middle Eastern craftspeople, while an Egyptian glass vessel from ca. 1400–1300 BCE showcases the range of brilliant colors that these experts were able to achieve. In fact, human-made materials were believed to be as powerful as naturally occurring ones, their brilliance and shine no less meaningful. The recipes for manufacturing these magical substances, which prescribed specific rituals to ensure a successful outcome, were closely held.

Source: The Institute for the Study of the Ancient World [September 30, 2019]



* This article was originally published here

Seagulls grab bread on the fly

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Channel: UFO Odessa  

I decided to feed the seagulls and fed them a loaf of bread, they pretty quickly catch it on the fly.

Video length: 6:35
Category: Entertainment
0 comments

World's oldest glue used from prehistoric times till the days of the Gauls


Birch bark tar, the oldest glue in the world, was in use for at least 50,000 years, from the Palaeolithic Period up until the time of the Gauls. Made by heating birch bark, it served as an adhesive for hafting tools and decorating objects.

World's oldest glue used from prehistoric times till the days of the Gauls
(A) Illustration of hinge (© S. Sorin, CNRS, CEPAM), based on Deschler-Erb 1998; (B) Hinge from Nice
(Transfert Massena; Alpes-Maritimes, sample MR6258); (C) Decorative plaque from Narbonne
 (sample MR6253) [Credit: J.-D. Strich, CNRS, CEPAM, & I. Rodet-Belarbi, INRAP, CEPAM]
Scientists mistakenly thought it had been abandoned in western Europe at the end of the Iron Age (800-25 BC) and replaced by conifer resins, around which a full-fledged industry developed during the Roman period.


But by studying artefacts that date back to the first six centuries AD through the lens of chemistry, archaeology, and textual analysis, researchers from the CNRS, Universite Nice Sophia Antipolis / Universite Cote d'Azur, and Inrap have discovered birch tar was being used right up to late antiquity, if not longer.

The artefacts in question -- found in a region where birch is scarce, thus raising the question of how it was procured -- are testimony to the strength of tradition among the Gauls.

The scientists' findings are published in Antiquity.

Source: CNRS [November 13, 2019]



* This article was originally published here

Ring Shaped UFOs Where Do They Come From??

239 views   35 likes   1 dislikes  

Channel: Terry's Theories  

I have found a new video of this ringed shaped object seen through a telescope from Mexico City. I have shown you guys several examples of there UFOs in the past. So guys where do these objects come from and what are there purpose.Leave me a comment and let's talk about it.

Source video 1 : https://www.youtube.com/watch?v=bmk9u4tBhiU&list=WL&index=5&t=0s
Source video 2 : https://www.youtube.com/watch?v=WhKiMxq21Xs
Source video 3 : https://www.youtube.com/watch?v=fvoqtEF2o_s
Source video 4 : https://www.youtube.com/watch?v=dlIF0P9j0cM&t=230s
Source video 5 : https://www.youtube.com/watch?v=nsvJWW3prS0&t=28s

Video length: 7:59
Category: Science & Technology
28 comments

* This article was originally published here

Limestone bearded head with a Corinthian helmet, Metropolitan...



Limestone bearded head with a Corinthian helmet, Metropolitan Museum of Art: Greek and Roman Art


The Cesnola Collection, Purchased by subscription, 1874–76 Metropolitan Museum of Art, New York, NY
Medium: Limestone

* This article was originally published here

Prehistoric Pottery, Dumfries Museum, Scotland, November 2019.

Prehistoric Pottery, Dumfries Museum, Scotland, November 2019.



* This article was originally published here

Space Station Science Highlights: Week of November 11, 2019













ISS - Expedition 61 Mission patch.

Nov. 15, 2019

Scientific investigations under way on the International Space Station include research on complex plasmas, controlling biofilms on spacecraft and more. On Friday, Nov. 15, ESA (European Space Agency) astronaut Luca Parmitano and NASA astronaut Drew Morgan conducted the first of a series of spacewalks to extend the life of the space station’s Alpha Magnetic Spectrometer (AMS-02). The AMS captures cosmic particles and measures their electrical charge in a search for dark matter and dark energy, which make up more than 90 percent of the total mass-energy of the universe.


Image above: NASA astronaut Drew Morgan and European Space Agency (ESA) astronaut Luca Parmitano conduct preparations for an extravehicular activity (EVA) to upgrade the Alpha Magnetic Spectrometer (AMS) on the outside of the space station to extend its search for dark matter in the universe. Image Credit: NASA.

This month marks the beginning of the 20th year of continuous human presence aboard the space station, the only platform for long-duration research in microgravity. The orbiting laboratory makes important contributions to Artemis, NASA’s program to go forward to the Moon and on to Mars.

Here are details on some of the science conducted during the week:

Microgravity enables research on complex plasma

The Plasma Krystall-4 (PK-4) investigation is a collaboration between the ESA and the Russian Federal Space Agency (ROSCOSMOS) to research complex plasmas. These low-temperature gaseous mixtures are composed of ionized gas, neutral gas and micron-sized particles or micro-particles. PK-4 investigates how the micro-particles become highly charged and interact, leading to self-organized structures called plasma crystals. Due to the strong influence of gravity on micro-particles, experiments on complex plasmas require microgravity conditions. The crew conducted PK-4 sessions, catching particle clouds inside the chamber.

Controlling microorganisms on spacecraft surfaces

International Space Station (ISS). Animation Credit: NASA

Biofilms are collections of one or more types of microorganisms – including bacteria, fungi and protists – that grow on wet surfaces. In spacecraft, biofilm formation can cause equipment malfunction and human illness and it could pose a serious problem on future long-term human space missions. The crew conducted operations for the Space Biofilms investigation, which characterizes the mass, thickness, structure, and associated gene expression of biofilms that form in space. The research includes analyzing different microbial species grown on a variety of materials, the role of the material surface on formation of biofilms, and testing of a novel surface containing a lubricant.

Toward printing human organs in space

Operations continued for the BioFabrication Facility (BFF). Biological printing of the tiny, complex structures found inside human organs, such as capillaries, is difficult in Earth’s gravity. Using the BFF to test the printing of human organs and tissues in microgravity is a first step toward a long-term plan to manufacture entire human organs in space using refined biological 3D printing techniques. The facility also may help maintain the health of crews on deep space exploration missions by producing food and personalized pharmaceuticals on demand.

Mapping neutron radiation exposure


Image above: Bubble detectors for Radi-N2, an investigation by the Canadian Space Agency (CSA) to characterize the neutron radiation environment on the space station. Astronauts absorb larger doses of neutron radiation than expected, and mapping exposure across the space station could help reveal sources of this exposure. Image Credit: NASA.

The crew deployed detectors for Radi-N2, an investigation by the Canadian Space Agency (CSA) to characterize the neutron radiation environment on the space station. Neutrons are nuclear "splinters" produced when cosmic rays strike the atoms of a spacecraft or the human body. Results are expected to help define the risk posed to the health of crew members and provide data to support development of advanced protective measures for future spaceflight. Radi-N2 repeats the measurements of Radi-N1, increasing the statistical accuracy of neutron measurements and allowing comparison of neutron fields at different periods of the solar cycle.

Other investigations on which the crew performed work:

- ACE-T-5 examines the physical and chemical characteristics of a new class of soft materials, bijels, which have a unique structure of two liquid phases separated by a layer of small particles or colloids. Bijels have significant potential for design and synthesis of composite materials.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7500

- Rodent Research-14 uses mice to examine the effects of disruptions to the body’s circatidal rhythm or sleep/wake cycle in microgravity on a cellular and key organ level. This 12-hour body clock is an important mechanism controlling stress-responsive pathways.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7906


Animation above: NASA astronaut Jessica Meir harvests leaves from Mizuna mustard greens for analysis and consumption during the Veg-04 experiment, part of a phased research project to address the need for fresh food production in space. Animation Credit: NASA.

- Veg-04B, part of a phased research project to address the need for fresh food production in space, focuses on the effects of light quality and fertilizer on a leafy crop, Mizuna mustard greens.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7895

- NutrISS assesses the body composition of crew members during spaceflight using a device that measures long-term energy balance modification over time. Adjusting diet to maintain a near-neutral energy balance and/or increasing protein intake may limit microgravity-induced bone and muscle loss.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7875

- Ring Sheared Drop examines formation of amyloid fibrils in microgravity. Abnormal fibrous deposits found in organs and tissues, amyloid fibrils are associated with neurodegenerative conditions such as Alzheimer’s disease.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7383

- Vascular Echo examines changes in blood vessels and hearts of crew members in space and their recovery upon return to Earth. Some returning crew members have much stiffer arteries after space flight.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1664

- Standard Measures captures a consistent set of measurements from crew members to characterize how their bodies adapt to living in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711

- Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions. “Menu fatigue” from repeatedly consuming a limited choice of foods may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

Related links:

Expedition 61: https://www.nasa.gov/mission_pages/station/expeditions/expedition61/index.html

Alpha Magnetic Spectrometer (AMS-02): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=729

Artemis: https://www.nasa.gov/artemis

Plasma Krystall-4 (PK-4): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1192

Space Biofilms: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7955

BioFabrication Facility (BFF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7599

Radi-N1: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=190

Radi-N2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=874

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Animations (mentioned), Images (mentioned), Text, Credits: NASA/Michael Johnson/John Love, Lead Increment Scientist Expedition 61.

Best regards, Orbiter.ch

* This article was originally published here

Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber


Most of our food is from angiosperms, while more than 90% of angiosperms require insect pollination - making this pollination method hugely important. Nevertheless, scientists have long been unclear as to when insect pollination first appeared.

Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber
Artist's rendering of A. burmitina feeding on eudicot flowers
[Credit: Ding-hau Yang]
Now, however, an international research group from China and the U.S. has provided the earliest evidence of insect-angiosperm pollination - by analyzing a sample of Cretaceous Burmese amber. The research was led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology (NIGPAS) of the Chinese Academy of Sciences. Results were published in Proceedings of the National Academy of Sciences.


Angiosperms, also known as flowering plants, originated in the Mesozoic and are the most diverse group of land plants, with approximately 300,000 known species. Their most distinguishing characteristic is the presence of true flowers. Angiosperms self-pollinate as well as use insects, animals, wind and water to achieve pollination, thus enhancing gene flow and increasing diversity.

Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber
A. burmitina in amber. The 99-million-year-old fossil, recovered from a mine in northern Myanmar,
also contains 62 pollen grains from a eudicot flower. It is the earliest known physical evidence
of insect pollination [Credit: Nanjing Institute of Geology and Palaeontology]
Angiosperms experienced rapid radiation by the mid-Cretaceous, which Darwin called an "abominable mystery." Since Darwin's time, numerous scholars have thought that insect pollination must be a key contributor to the Cretaceous radiation of angiosperms since insects and flowering plants were both common by this time. However, direct evidence of a Cretaceous insect-angiosperm pollination mode was missing and related theories remained hypothetical until now.


Working with Burmese amber dating to the mid-Cretaceous - 99 million years ago - the researchers discovered evidence of beetle pollination, thus confirming the hypothesis of Cretaceous insect-angiosperm interaction and offering the earliest evidence for entomophily.

Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber
Close up of A. burmitina in amber. The fossil also contains 62 pollen grains from a eudicot flower, which
indicates the insect's role as a pollinator [Credit: Nanjing Institute of Geology and Palaeontology]
The beetle specimen in the amber sample is a new species within the family Mordellidae, named Angimordella burmitina. Extant Mordellidae beetles are a typical flower-visiting group. Commonly, they are known as "tumbling flower beetles" for the irregular movements they make when escaping predators, due to having an elongated pygidium (an external posterior body part or shield in arthropods).


A. burmitina is distinguished from most extant species by a poorly developed pygidium and enlarged, very well-developed hind legs. Based on these features, the scientists believe A. burmitina utilized a different movement mechanism than other species, preferring to jump or fly between corollas and plants. The mouth part of A. burmitina is also highly evolved for pollen collection, with enlargement of part of the maxillary palps, which are leg-like structures near the mouth.

Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber
Ecological reconstruction of the Cretaceous tumbling flower beetle
[Credit: NIGPAS]
Numerous pollen grains were preserved on or near the A. burmitina specimen. To examine them closely, the research team performed high-precision grinding and polishing of the amber sample, then applied confocal laser scanning microscopy and optical photomicrography. Using these methods, the scientists identified the pollen grains as tricolpate, meaning they each have three pores and come from a type of flowering plant known as a eudicot. Their surface texture, size, and clumping also show that the pollen is zoophilous, making it more likely to be picked up by an animal such as a beetle.

Based on the entomological and palynological evidence, the research team believes this amber specimen proves a beetle-angiosperm pollination mode, supporting the hypothesis that specialized insect pollination modes were present in eudicots at least 99 million years ago. Previous evidence of insect pollination of flowering plants dates to the Middle Eocene, around 45-48 million years ago. Thus, the current finding extends the history of insect pollination of flowering plants by around 50 million years and suggests that such mutualism existed at least as far back as 99 million years ago.

Author: LI Yuan | Source: Chinese Academy of Science [November 11, 2019]



* This article was originally published here

Hubble Spots a Curious Spiral













NASA - Hubble Space Telescope patch.

Nov. 15, 2019


The universe is simply so vast that it can be difficult to maintain a sense of scale. Many galaxies we see through telescopes such as the NASA/ESA Hubble Space Telescope, the source of this beautiful image, look relatively similar: spiraling arms, a glowing center, and a mixture of bright specks of star formation and dark ripples of cosmic dust weaving throughout.

This galaxy, a spiral galaxy named NGC 772, is no exception. It actually has much in common with our home galaxy, the Milky Way. Each boasts a few satellite galaxies, small galaxies that closely orbit and are gravitationally bound to their parent galaxies. One of NGC 772’s spiral arms has been distorted and disrupted by one of these satellites (NGC 770 — not visible in the image here), leaving it elongated and asymmetrical.

However, the two are also different in a few key ways. For one, NGC 772 is both a peculiar and an unbarred spiral galaxy; respectively, this means that it is somewhat odd in size, shape or composition, and that it lacks a central feature known as a bar, which we see in many galaxies throughout the cosmos — including the Milky Way. These bars are built of gas and stars, and are thought to funnel and transport material through the galactic core, possibly fueling and igniting various processes such as star formation.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: ESA (European Space Agency)/NASA/Isabelle Yan/Image, Animation Credits: ESA/Hubble & NASA, A. Seth et al.

Greetings, Orbiter.ch

* This article was originally published here

'Ghost' footprints from Pleistocene era revealed by radar tech


Invisible footprints hiding since the end of the last ice age - and what lies beneath them - have been discovered by Cornell University researchers using a special type of radar in a novel way.

'Ghost' footprints from Pleistocene era revealed by radar tech
The researchers collecting GPR data at White Sands National Monument in New Mexico
 [Credit: Cornell University]
The fossilized footprints reveal a wealth of information about how humans and animals moved and interacted with each other 12,000 years ago.


"We never thought to look under footprints," said Thomas Urban, research scientist at Cornell and lead author on the study. "But it turns out that the sediment itself has a memory that records the effects of the animal's weight and momentum in a beautiful way. It gives us a way to understand the biomechanics of extinct fauna that we never had before."

The researchers examined the footprints of humans, mammoths and giant sloths in the White Sands National Monument in New Mexico. Using ground-penetrating radar (GPR), they were able to resolve 96% of the human tracks in the area under investigation, as well as all of the larger vertebrate tracks.

'Ghost' footprints from Pleistocene era revealed by radar tech
Human footprints from the last Ice Age at White Sands National Monument in New Mexico
[Credit: Matthew Robert Bennett]
"But there are bigger implications than just this case study," Urban said. "The technique could possibly be applied to many other fossilized footprint sites around the world, potentially including those of dinosaurs. We have already successfully tested the method more broadly at multiple locations within White Sands."


While these "ghost" footprints can become invisible for a short time after rain and when conditions are just right, "now, using geophysics methods, they can be recorded, traced and investigated in 3D to reveal Pleistocene animal and human interactions, history and mechanics in genuinely exciting new ways," said co-author Sturt Manning, archaeology professor.

GPR is a nondestructive method that allows researchers to access hidden information without the need for excavation. The sensor - a kind of antenna - is dragged over the surface, sending a radio wave into the ground. The signal that bounces back gives a picture of what's under the surface.

'Ghost' footprints from Pleistocene era revealed by radar tech
The pressure data from the mammoth footprints closely resembled those of modern elephants
[Credit: Matthew Robert Bennett]
In addition to this biomechanical treasure trove of data, the GPR technique gives researchers a way to learn about what early humans did when they were not at a campsite or kill site, the two types of archaeological sites best known for this time period.

The study is published in Scientific Reports.

Author: Linda B. Glaser | Source: Cornell University [November 11, 2019]



* This article was originally published here

Astronaut out! Thank you for all the amazing questions. Make sure to follow us on Tumblr for your...

Astronaut out! Thank you for all the amazing questions.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

New NASA Study Reveals Origin of Organic Matter in Apollo Lunar Samples













NASA - Apollo 12 Mission patch.

November 15, 2019

A team of NASA-funded scientists has solved an enduring mystery from the Apollo missions to the moon – the origin of organic matter found in lunar samples returned to Earth. Samples of the lunar soil brought back by the Apollo astronauts contain low levels of organic matter in the form of amino acids. Certain amino acids are the building blocks of proteins, essential molecules used by life to build structures like hair and skin and to regulate chemical reactions.


Image above: Astronaut Alan L. Bean, Lunar Module pilot for the Apollo 12 lunar landing mission, holds a container filled with lunar soil collected while exploring the lunar surface. Astronaut Charles "Pete" Conrad Jr., commander, who took this picture, is reflected in the helmet visor. Image Credit: NASA.

Since the lunar surface is completely inhospitable for known forms of life, scientists don't think the organic matter came from life on the moon. Instead, they think the amino acids could have come from four possible sources. First, since traces of life are everywhere on Earth, the amino acids could be simply contamination from terrestrial sources, either from material brought to the moon by the missions, or from contamination introduced while the samples were being handled back on Earth.

Second, rocket exhaust from the lunar modules contains precursor molecules used to build amino acids (such as hydrogen cyanide or HCN). This contamination could produce amino acids during lunar sample analysis in the lab.

Third, the solar wind – a thin stream of electrically conducting gas continuously blown off the surface of the Sun -- contains the elements used to make amino acids, such as hydrogen, carbon, and nitrogen. Just like contamination from lunar module exhaust, material from the solar wind could produce amino acids during sample workup.

Fourth, chemical reactions inside asteroids make amino acids. Fragments from asteroid collisions occasionally fall to Earth as meteorites, bringing their extraterrestrial amino acids with them. The lunar surface is frequently bombarded by meteorites and could have amino acids from asteroids as well.

"People knew amino acids were in the lunar samples, but they didn't know where they came from," said Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The scientists in the 1970s knew the right questions to ask and they tried pretty hard to answer them, but they were limited by the analytical capabilities of the time. We have the technology now, and we've determined that most of the amino acids came from terrestrial contamination, with perhaps a small contribution from meteorite impacts." Elsila is lead author of a paper on this research appearing online in Geochimica et Cosmochimica Acta Oct. 28.

The team analyzed seven samples taken during the Apollo missions and stored in a NASA curation facility since return to Earth, and found amino acids in all of them at very low concentrations (105 to 1,910 parts-per-billion). One of the key new capabilities of the Goddard Astrobiology Analytical Laboratory was instrumentation with high enough sensitivity to determine the isotopic composition of an amino acid molecule, according to Elsila. This capability enabled the team to say terrestrial contamination was the primary source of the lunar amino acids.


Image above: Astronaut Alan L. Bean is photographed hammering a double core tube (collecting samples) near Halo Crater during the second Extravehicular Activity EVA 2 of the Apollo 12 mission. Image Credits: NASA/Apollo 12.

Isotopes are versions of an element; for example, Carbon-13 has an extra neutron and is a more massive version of the common Carbon-12. Life prefers to use the lighter Carbon-12, which reacts a bit more readily, so amino acid molecules from terrestrial life will have less Carbon-13 compared to amino acids produced by non-biological reactions in asteroids. This is what the team found in one of the lunar samples that was abundant enough for isotopic analysis. The isotopic composition of the amino acids (glycine, β-alanine, and L-alanine) had less Carbon-13 and more closely resembled that from terrestrial sources than that from meteorites.

Isotopic composition also helped rule out the solar wind as the source, since the solar wind has far less Carbon-13 than what was found in the sample.

Also, if the solar wind were responsible for the amino acids, then samples taken from near the lunar surface, which had the highest exposure to the solar wind, should have a greater abundance of amino acids than samples taken from deeper beneath the surface. This is the opposite of what was found – the deepest samples, which were the most sheltered from the solar wind, produced the most amino acids.

A similar result on amino acid abundances helped rule out the lunar module exhaust as a source. If contamination from the exhaust produced the amino acids, then a sample taken from right under the Apollo 17 lunar module should have more amino acids than a sample taken far away. However, the team found that a sample taken from 6.5 kilometers (four miles) away had similar amino acid abundances to the one taken beneath the module.

The ability to determine the orientation of an amino acid molecule was another significant new capability of the Goddard lab that enabled them to discover the origin of the lunar amino acids, according to Elsila. Amino acid molecules can be built in two versions – left and right -- that are mirror images of each other, like your hands. Terrestrial life uses the left-handed versions, while non-biological chemistry produces the left-handed and right-handed varieties in equal amounts. In the samples, the team found that the left-handed versions were far more common than right-handed ones for several types of amino acids used to make proteins. Since life uses the left-handed versions, this suggests terrestrial life as the source of these amino acids.

Although most of the amino acids likely came from Earth, the team can't rule out a contribution from meteorites because they found some amino acids that are extremely rare in terrestrial biology but common in meteorites (for example, Alpha-aminoisobutyric acid or AIB). This discovery suggests meteorites may make a small contribution to the amino acids found on the lunar surface, according to Elsila.

The research has important implications for future missions that are looking for extraterrestrial organic matter that may be present, but in very small (trace) amounts. "This work highlights the fact that even with thoughtful and careful contamination control efforts, trace organics in extraterrestrial samples can be overwhelmed by terrestrial sources," said Elsila. "Future missions emphasizing organic analysis must consider not only contamination control but also include 'witness samples' that record the environment and potential contamination as the mission is built and launched to understand the unavoidable contamination background."

This is a lesson taken to heart by NASA's OSIRIS-REx mission, which launches in 2016 to return pristine samples of asteroid Bennu in 2023.

The Apollo samples were taken in the late 1960's and early 1970's, and highlight the lasting value of sample return missions. "These samples were collected before I was born, and the techniques used in our study were not yet invented when the samples were collected; curation of the samples for future work allowed us to identify the origins of the amino acids detected in the samples, a question that the original investigators were unable to resolve," said Elsila.

The research was supported by NASA's Lunar Advanced Science and Exploration Research (LASER) Program, as well as the NASA Astrobiology Institute, administered by NASA's Ames Research Center in Mountain View, California, and the Goddard Center for Astrobiology. The team includes researchers from NASA's Johnson Space Center, Houston and Goddard.

Related articles:

50 Years Ago: Return to the Moon
https://orbiterchspacenews.blogspot.com/2019/11/50-years-ago-return-to-moon.html

NASA Opens Previously Unopened Apollo Sample Ahead of Artemis Missions
https://orbiterchspacenews.blogspot.com/2019/11/nasa-opens-previously-unopened-apollo.html

Related links:

Apollo 12: https://www.nasa.gov/mission_pages/apollo/apollo-12

Apollo missions: http://www.nasa.gov/mission_pages/apollo/index.html

Goddard Astrobiology Analytical Laboratory: http://science.gsfc.nasa.gov/691/analytical/

NASA Astrobiology Institute: https://astrobiology.nasa.gov/nai/

Earth's Moon: http://www.nasa.gov/moon

OSIRIS-REx mission: http://www.nasa.gov/mission_pages/osiris-rex/index.html

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center, Bill Steigerwald.

Greetings, Orbiter.ch

* This article was originally published here

At future Mars landing spot, scientists spy mineral that could preserve signs of past life


Next year, NASA plans to launch a new Mars rover to search for signs of ancient life on the Red Planet. A new study shows that the rover's Jezero crater landing site is home to deposits of hydrated silica, a mineral that just happens to be particularly good at preserving biosignatures.

At future Mars landing spot, scientists spy mineral that could preserve signs of past life
Jezero crater, where NASA plans to land a new Mars rover next year, is home to the remains of an ancient river delta.
Researchers have now found deposits of hydrated silica, a mineral that's especially good at preserving microfossils
and other signs of past life, near the delta [Credit: NASA/JPL/JHUAPL/MSSS/Brown University]
"Using a technique we developed that helps us find rare, hard-to-detect mineral phases in data taken from orbiting spacecraft, we found two outcrops of hydrated silica within Jezero crater," said Jesse Tarnas, a Ph.D. student at Brown University and the study's lead author. "We know from Earth that this mineral phase is exceptional at preserving microfossils and other biosignatures, so that makes these outcrops exciting targets for the rover to explore."

NASA announced late last year that its Mars 2020 rover would be headed to Jezero, which appears to have been home to an ancient lake. The star attraction at Jezero is a large delta deposit formed by ancient rivers that fed the lake. The delta would have concentrated a wealth of material from a vast watershed. Deltas on Earth are known to be good at preserving signs of life.


Adding hydrated silica to the mix at Jezero increases that preservation potential, the researchers say. One of the silica deposits was found on the edge of the delta at low elevation. It's possible that the minerals formed in place and represent the bottom layer of the delta deposit, which is a great scenario for preserving signs of life.

"The material that forms the bottom layer of a delta is sometimes the most productive in terms of preserving biosignatures," said Jack Mustard, a professor at Brown and study co-author. "So if you can find that bottomset layer, and that layer has a lot of silica in it, that's a double bonus."

For the study, researchers used data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument that flies aboard NASA's Mars Reconnaissance Orbiter. The technique applied to the CRISM data used big data analysis methods to tease out the weak spectral signature of the silica deposits.

At future Mars landing spot, scientists spy mineral that could preserve signs of past life
A false-colour image of Jezero crater shows the edge of an ancient river delta, where researchers
have spied hydrated silica, a mineral that's especially good at preserving microfossils
and other signs of past life [Credit: NASA]
While the geologic context of the deposits suggests they could have formed at the base of the delta, it's not the only possibility, the researchers say. The minerals could have formed upstream in the watershed that fed Jezero and been washed subsequently into the crater, by volcanic activity or later episodes of water saturation in the Jezero crater lake. The rover should be able to isolate the real source, the researchers say.

"We can get amazing high-resolution images and compositional data from orbit, but there's a limit on what we can discern in terms of how these minerals formed," Tarnas said. "Given instruments on the rover, however, we should be able to constrain the origin of these deposits."


The rover will be able to perform fine-scale chemical analysis of the deposits and provide a close-up view of how the deposits are situated in relation to surrounding rock units. It will also have a sensor similar to CRISM to link orbital and lander data. That will go a long way to determining how the deposits formed. What's more, one instrument aboard the rover is able to look for complex organic material. If the silica deposits have high concentrations of organics, it would be an especially intriguing find, the researchers say.

And in addition to the work the rover does on site, it will also cache samples to be returned to Earth by future missions.

"If these deposits present themselves in the form of rocks that are big and competent enough to drill into, they could be put into the cache," Mustard said. "This work suggests that they'd be a great sample to have."

The research is published in Geophysical Research Letters.

Source: Brown University [November 12, 2019]



* This article was originally published here

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