вторник, 12 ноября 2019 г.

Space Station Science Highlights: Week of November 4, 2019













ISS - Expedition 61 Mission patch.

Nov. 12, 2019

Crew members on the International Space Station conducted a variety of scientific investigations this past week, including research into colloid gels, the effects of disrupting the body’s daily clock and more. Monday morning, Northrop Grumman’s Cygnus cargo craft carrying more than 8,000 pounds of research and supplies docked to the space station as it flew over the South Pacific Ocean. The commercial resupply mission is the 12th for the company and is in orbit at the same time as NG CRS-11, which launched in April.


Image above: NASA astronaut Andrew Morgan and ESA (European Space Agency) astronaut Luca Parmitano create tape flags for use in the upcoming spacewalks to service the Alpha Magnetic Spectrometer. Parmitano would soon after use the Space Linear Acceleration Mass Measurement Device (SLAMMD) to measure an astronaut’s mass using Newton’s Second Law of Motion. SLAMMD applies a known force to an attached astronaut and uses the resulting acceleration to calculate that astronaut’s mass. Image Credit: NASA.

Nov. 2 marked the beginning of the 20th year of continuous human presence aboard the space station, which so far has hosted 239 people and more than 2,700 science experiments. 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.


Image above: This black-and-white infrared photograph shows Northrop Grumman’s Antares rocket with the Cygnus resupply spacecraft onboard launching from NASA’s Wallops Facility Saturday, Nov. 2. The company’s 12th contracted cargo resupply mission with NASA delivered about 8,200 pounds of science and research, supplies and hardware to the orbital laboratory and crew. Image Credits: NASA/Bill Ingalls.

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

Improving product shelf life

Operations for Advanced Colloids Experiment-Temperature-6 (ACE-T-6) are running for 16-hours every other day for the next three weeks. The investigation studies the microscopic behavior of colloids in gels and creams to provide new insight into fundamental interactions that may improve product shelf life. Colloids, suspensions of microscopic particles in a liquid, are used in products ranging from milk to fabric softener. Consumer products often use colloidal gels to distribute specialized ingredients such as droplets that soften fabrics. These gels must serve two opposite purposes, however: dispersing the active ingredient so it can work while maintaining an even distribution so the product does not spoil.


Image above: NASA astronauts Christina Koch and Jessica Meir are inside the cupola practicing the Canadarm2 robotics techniques they would use to capture the Northrop Grumman Cygnus space freighter when it arrived Nov. 4 with more than four tons of science experiments, crew supplies and station hardware. Image Credit: NASA.

Protecting the body clock

Crew members installed four Rodent Habitats for Rodent Research-14 (RR-14), which 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. The 12-hour body clock is an important mechanism controlling stress-responsive pathways, and the space station provides an ideal setting to examine this role. Researchers can analyze responses in the mice at the cellular level as well as effects on behavior.

Students see Earth from space


Image above: An image of Corinth, Greece, taken from the space station by the Sally Ride EarthKAM’s November, 2019 Mission 68. Image Credit: EarthKAM.

Sally Ride EarthKAM allows students remotely controlling a digital camera on the International Space Station to photograph and examine Earth from an astronaut’s perspective. Students select coastlines, mountain ranges and other geographic items of interest to photograph, and the EarthKAM team posts these images on the Internet for viewing by the public and participating classrooms around the world. Crew members set up the EarthKam on Monday for Mission 68’s weeklong imaging session.

Other investigations on which the crew performed work:

- 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

- BEST studies the use of DNA sequencing to identify microbial organisms and improve understanding of how humans, plants and microbes adapt to living in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687

- 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

- ISS HAM or Amateur Radio on the International Space Station lets students around the world talk directly with crew members on the space station, inspiring them to pursue careers in science, technology, engineering and math and engaging them with radio science technology through amateur radio.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337

- 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 than when they went into space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1664

- The ISS Experience creates virtual reality videos from footage covering different aspects of crew life, execution of science and the international partnerships involved on the space station.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7877

- 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

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Scientists further refine how quickly the universe is expanding


Wielding state-of-the-art technologies and techniques, a team of Clemson University astrophysicists has added a novel approach to quantifying one of the most fundamental laws of the universe.

Scientists further refine how quickly the universe is expanding
The team’s analysis paves the way for better measurements in the future using telescopes
from the Cherenkov Telescope Array [Credit: Daniel Lopez/IAC]
In a paper published in The Astrophysical Journal, Clemson scientists Marco Ajello, Abhishek Desai, Lea Marcotulli and Dieter Hartmann have collaborated with six other scientists around the world to devise a new measurement of the Hubble Constant, the unit of measure used to describe the rate of expansion of the universe.

"Cosmology is about understanding the evolution of our universe—how it evolved in the past, what it is doing now and what will happen in the future," said Ajello, an associate professor in the College of Science's department of physics and astronomy. "Our knowledge rests on a number of parameters—including the Hubble Constant—that we strive to measure as precisely as possible. In this paper, our team analyzed data obtained from both orbiting and ground-based telescopes to come up with one of the newest measurements yet of how quickly the universe is expanding."

The concept of an expanding universe was advanced by the American astronomer Edwin Hubble (1889-1953), who is the namesake for the Hubble Space Telescope. In the early 20th century, Hubble became one of the first astronomers to deduce that the universe was composed of multiple galaxies. His subsequent research led to his most renowned discovery: that galaxies were moving away from each other at a speed in proportion to their distance.


Hubble originally estimated the expansion rate to be 500 kilometers per second per megaparsec, with a megaparsec being equivalent to about 3.26 million light years. Hubble concluded that a galaxy two megaparsecs away from our galaxy was receding twice as fast as a galaxy only one megaparsec away. This estimate became known as the Hubble Constant, which proved for the first time that the universe was expanding. Astronomers have been recalibrating it—with mixed results—ever since.

With the help of skyrocketing technologies, astronomers came up with measurements that differed significantly from Hubble's original calculations—slowing the expansion rate down to between 50 and 100 kilometers per second per megaparsec. And in the past decade, ultra-sophisticated instruments, such as the Planck satellite, have increased the precision of Hubble's original measurements in relatively dramatic fashion.

In a paper titled "A New Measurement of the Hubble Constant and Matter Content of the Universe using Extragalactic Background Light-Gamma Ray Attenuation," the collaborative team compared the latest gamma-ray attenuation data from the Fermi Gamma-ray Space Telescope and Imaging Atmospheric Cherenkov Telescopes to devise their estimates from extragalactic background light models. This novel strategy led to a measurement of approximately 67.5 kilometers per second per megaparsec.

Gamma rays are the most energetic form of light. Extragalactic background light (EBL) is a cosmic fog composed of all the ultraviolet, visible and infrared light emitted by stars or from dust in their vicinity. When gamma rays and EBL interact, they leave an observable imprint - a gradual loss of flow—that the scientists were able to analyze in formulating their hypothesis.


"The astronomical community is investing a very large amount of money and resources in doing precision cosmology with all the different parameters, including the Hubble Constant," said Dieter Hartmann, a professor in physics and astronomy. "Our understanding of these fundamental constants has defined the universe as we now know it. When our understanding of laws becomes more precise, our definition of the universe also becomes more precise, which leads to new insights and discoveries."

A common analogy of the expansion of the universe is a balloon dotted with spots, with each spot representing a galaxy. When the balloon is blown up, the spots spread farther and farther apart.

"Some theorize that the balloon will expand to a particular point in time and then re-collapse," said Desai, a graduate research assistant in the department of physics and astronomy. "But the most common belief is that the universe will continue to expand until everything is so far apart there will be no more observable light. At this point, the universe will suffer a cold death. But this is nothing for us to worry about. If this happens, it will be trillions of years from now."

But if the balloon analogy is accurate, what is it, exactly, that is blowing up the balloon?

"Matter - the stars, the planets, even us—is just a small fraction of the universe's overall composition," Ajello explained. "The large majority of the universe is made up of dark energy and dark matter. And we believe it is dark energy that is 'blowing up the balloon.' Dark energy is pushing things away from each other. Gravity, which attracts objects toward each other, is the stronger force at the local level, which is why some galaxies continue to collide. But at cosmic distances, dark energy is the dominant force."


The other contributing authors are lead author Alberto Dominguez of the Complutense University of Madrid; Radek Wojtak of the University of Copenhagen; Justin Finke of the Naval Research Laboratory in Washington, D.C.; Kari Helgason of the University of Iceland; Francisco Prada of the Instituto de Astrofisica de Andalucia; and Vaidehi Paliya, a former postdoctoral researcher in Ajello's group at Clemson who is now at Deutsches Elektronen-Synchrotron in Zeuthen, Germany.

"It is remarkable that we are using gamma rays to study cosmology. Our technique allows us to use an independent strategy—a new methodology independent of existing ones—to measure crucial properties of the universe," said Dominguez, who is also a former postdoctoral researcher in Ajello's group. "Our results show the maturity reached in the last decade by the relatively recent field of high-energy astrophysics. The analysis that we have developed paves the way for better measurements in the future using the Cherenkov Telescope Array, which is still in development and will be the most ambitious array of ground-based high-energy telescopes ever."

Many of the same techniques used in the current paper correlate to previous work conducted by Ajello and his counterparts. In an earlier project, which appeared in the journal Science, Ajello and his team were able to measure all of the starlight ever emitted in the history of the universe.

"What we know is that gamma-ray photons from extragalactic sources travel in the universe toward Earth, where they can be absorbed by interacting with the photons from starlight," Ajello said. "The rate of interaction depends on the length that they travel in the universe. And the length that they travel depends on expansion. If the expansion is low, they travel a small distance. If the expansion is large, they travel a very large distance. So the amount of absorption that we measured depended very strongly on the value of the Hubble Constant. What we did was turn this around and use it to constrain the expansion rate of the universe."

Author: Jim Melvin | Source: Clemson University [November 08, 2019]



* This article was originally published here

Leading the way














ESA - Beyond Mission patch / EVA - Extra Vehicular Activities patch.

Nov. 12, 2019


Four spacewalks in the coming weeks means a lot of prep work. ESA astronaut Luca Parmitano is gearing up the first in a series of historic extravehicular activities or EVAs taking place 15 November. He is pictured here creating tape flags that will be used to mark tubes during the spacewalks.

The spacewalks are to service the Alpha Magnetic Spectrometer or AMS, a dark matter hunter that is providing researchers with data on cosmic ray particles well beyond its three-year mission.

Installed outside the International Space Station in 2011, the instrument has recorded over 140 billion particles to date along with their mass, velocity, and charge and direction of travel. This data is helping scientists track down and understand the sources of dark matter, an invisible energy that makes up roughly 90% of the universe.

As expected, the harsh environment of space began to wear down the facility. One by one, the cooling pumps keeping a vital detector at a constant temperature began to fail, affecting the data collection.

Plans for spacewalks to upgrade the pumps have been in the making for years to keep the science going.

Never intended to be serviced in orbit, the AMS maintenance will be complex.

For starters, AMS-02 has over 300,000 data channels. There are also no handrails or foot restraints installed around the instrument to access the cooling system that needs maintenance. New tools are also needed, as astronauts have never cut and reconnected fluid lines in a bulky spacesuit before.

Luca trained well in advance for these spacewalks at NASA’s Johnson Space Center in Houston, USA. New tools and procedures were extensively tested, with a lot of know-how drawn from the last series of complex spacewalks to extend the life of a valuable space instrument, the Hubble Space telescope.


Image above: This picture, taken by NASA astronaut Ron Garan during a spacewalk on July 12, 2011, shows the International Space Station with space shuttle Atlantis docked at the edge of the frame on the far right and a Russian Soyuz spacecraft docked to Pirs, below the sun. In the foreground is the Alpha Magnetic Spectrometer (AMS) experiment installed during the STS-134 mission. AMS is a state-of-the-art particle physics detector designed to use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe's origin by searching for antimatter and dark matter, and measuring cosmic rays. Image Credits: NASA/Ron Garan.

Now that the latest Cygnus cargo supply mission has brought the final tools needed, Luca and NASA astronaut Andrew Morgan are ready to go.

Luca will play a leading role as EV-1, wearing a white spacesuit with red stripes while Andrew wears the white spacesuit with no stripes. It is the first time a European astronaut has held the lead position.

The pair will be supported by NASA astronauts Christina Koch and Jessica Meir who will operate the Canadarm2 robotic arm from inside the Station. This will help position the astronauts around their hard-to-reach work site, located on top of the Station’s S3 Truss structure between a pair of solar arrays and radiators.

The entire spacewalk is expected to take around six hours and it will set the scene for at least three more.

The spacewalk will be streamed live on ESA Web TV from 12:50 CET (11:50 GMT) and ESA’s Facebook page. The first two hours of the broadcast will feature commentary from astronaut and operation experts at ESA’s astronaut centre in Cologne, Germany, as well as a live cross with scientists at the CERN European Laboratory for Particle Physics.

Related article:

Luca to lead most challenging spacewalks since Hubble repairs
https://orbiterchspacenews.blogspot.com/2019/11/luca-to-lead-most-challenging.html

Related links:

ESA Web TV: http://www.esa.int/ESA_Multimedia/ESA_Web_TV

NASA TV: https://www.nasa.gov/live

Alpha Magnetic Spectrometer (AMS): https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station/AMS_ready_to_discover_the_particle_universe

Human Spaceflight: http://www.esa.int/ESA_Multimedia/Directorates/Human_Spaceflight/

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

Images, Text, Credits: ESA/NASA.

Best regards, Orbiter.ch

* This article was originally published here

Superfood for Mesozoic herbivores?


The long-necked, big bodied sauropod dinosaurs comprise some of the largest terrestrial vertebrates to walk the earth. These behemoths were herbivores that survived solely on plant material. There has been long speculation as to what food resources could have supported their size, particularly when young and growing fast. New research being presented at this year's annual meeting of the Society of Vertebrate Paleontology held this year in Brisbane, Australia by lead author, Carole Gee, University of Bonn, Germany, points to a plant commonly known as the horsetail.

Superfood for Mesozoic herbivores?
Equisetum, the Power Food of Mesozoic? [Credit: C.T. Gee]
Equisetum is a spore-bearing plant commonly known as the "scouring rush" or "horsetail," and close relatives of the modern genus are known in the fossil record as far back as the Triassic. Gee and co-authors studied the digestive fermentation and comparative calorie yield of seven extant species of Equisetum for living herbivores using a standardized feed evaluation test.


Their data confirm earlier studies that suggest Equisetum was an important, highly digestible, nutritious, and therefore preferred food source for herbivorous dinosaurs in Mesozoic times. "My approach to understanding the paleobiology of ancient plants and deep-time plant-animal interactions is not only to look at paleontology, but also to include studies of living plants and their ecology, as well as the dietary habits of living animals," says Gee.

Superfood for Mesozoic herbivores?
The long-necked, big bodied sauropod dinosaurs comprise some of the largest terrestrial vertebrates to walk the earth.
These behemoths were herbivores that survived solely on plant material. There has been long speculation as to what
food resources could have supported their size, particularly when young and growing fast. New research being
presented at this year's annual meeting of the Society of Vertebrate Paleontology held this year
in Brisbane, Australia [Credit: C.T. Gee]
In this study, Gee and her colleagues turn their attention to the diets of hatchling and young sauropods, as well as other small-stature herbivorous dinosaurs. "Up to now, plants used as likely food resources have only been studied for fully-grown sauropods," Dee stated.

Young and growing sauropods grow very quickly, recognizing the value of Equisetum as a major food source for young and growing sauropods is extremely important in learning more about their growth. Gee and her colleagues began research on the comparative value of the nearest living relatives of the Jurassic flora as dinosaur fodder about a decade ago within the framework of a Research Unit on the Biology of the Sauropod Dinosaurs, funded by the German Research Foundation.

Source: Federation of American Societies for Experimental Biology [November 08, 2019]



* This article was originally published here

SPACE: A Global Frontier

Space is a global frontier. That’s why we partner with nations all around the world to further the advancement of science and to push the boundaries of human exploration. With international collaboration, we have sent space telescopes to observe distant galaxies, established a sustainable, orbiting laboratory 254 miles above our planet’s surface and more! As we look forward to the next giant leaps in space exploration with our Artemis lunar exploration program, we will continue to go forth with international partnerships!

Teamwork makes the dream work. Here are a few of our notable collaborations:

Artemis Program

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Our Artemis lunar exploration program will send the first woman and the next man to the Moon by 2024. Using innovative technologies and international partnerships, we will explore more of the lunar surface than ever before and establish sustainable missions by 2028.

During these missions, the Orion spacecraft will serve as the exploration vehicle that will carry the crew to space, provide emergency abort capability and provide safe re-entry from deep space return velocities. The European Service Module, provided by the European Space Agency, will serve as the spacecraft’s powerhouse and supply it with electricity, propulsion, thermal control, air and water in space.

image

The Gateway, a small spaceship that will orbit the Moon, will be a home base for astronauts to maintain frequent and sustainable crewed missions to the lunar surface. With the help of a coalition of nations, this new spaceship will be assembled in space and built within the next decade.

Gateway already has far-reaching international support, with 14 space agencies agreeing on its importance in expanding humanity’s presence on the Moon, Mars and deeper into the solar system.

International Space Station

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The International Space Station (ISS) is one of the most ambitious international collaborations ever attempted. Launched in 1998 and involving the U.S., Russia, Canada, Japan and the participating countries of the European Space Agency — the ISS has been the epitome of global cooperation for the benefit of humankind. The largest space station ever constructed, the orbital laboratory continues to bring together international flight crews, globally distributed launches, operations, training, engineering and the world’s scientific research community.

Hubble Space Telescope 

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The Hubble Space Telescope, one of our greatest windows into worlds light-years away, was built with contributions from the European Space Agency (ESA).

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ESA provided the original Faint Object Camera and solar panels, and continues to provide science operations support for the telescope. 

Deep Space Network

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The Deep Space Network (DSN) is an international array of giant radio antennas that span the world, with stations in the United States, Australia and Spain. The three facilities are equidistant approximately one-third of the way around the world from one another – to permit constant communication with spacecraft as our planet rotates. The network supports interplanetary spacecraft missions and a few that orbit Earth. It also provides radar and radio astronomy observations that improve our understanding of the solar system and the larger universe!

Mars Missions 

Information gathered today by robots on Mars will help get humans to the Red Planet in the not-too-distant future. Many of our Martian rovers – both past, present and future – are the products of a coalition of science teams distributed around the globe. Here are a few notable ones:

Curiosity Mars Rover 

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  • France: ChemCam, the rover’s laser instrument that can analyze rocks from more than 20 feet away
  • Russia: DAN, which looks for subsurface water and water locked in minerals
  • Spain: REMS, the rover’s weather station

InSight Mars Lander

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  • France with contributions from Switzerland: SEIS, the first seismometer on the surface of another planet
  • Germany: HP3, the heatflow probe that will help us understand the interior structure of Mars
  • Spain: APSS, the lander’s weather station

Mars 2020 Rover

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  • Norway: RIMFAX, a ground-penetrating radar
  • France: SuperCam, the laser instrument for remote science
  • Spain: MEDA, the rover’s weather station

Space-Analog Astronaut Training

We partner with space agencies around the globe on space-analog missions. Analog missions are field tests in locations that have physical similarities to the extreme space environments. They take astronauts to space-like environments to prepare as international teams for near-term and future exploration to asteroids, Mars and the Moon.

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The European Space Agency hosts the Cooperative Adventure for Valuing and Exercising human behavior and performance Skills (CAVES) mission. The two week training prepares multicultural teams of astronauts to work safely and effectively in an environment where safety is critical. The mission is designed to foster skills such as communication, problem solving, decision-making and team dynamics.

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We host our own analog mission, underwater! The NASA Extreme Environment Mission Operations (NEEMO) project sends international teams of astronauts, engineers and scientists to live in the world’s only undersea research station, Aquarius, for up to three weeks. Here, “aquanauts” as we call them, simulate living on a spacecraft and test spacewalk techniques for future space missions in hostile environments.

International Astronautical Congress 

So, whether we’re collaborating as a science team around the globe, or shoulder-to-shoulder on a spacewalk, we are committed to working together with international partners for the benefit of all humanity! 

If you’re interested in learning more about how the global space industry works together, check out our coverage of the 70th International Astronautical Congress (IAC) happening this week in Washington, D.C. IAC is a yearly gathering in which all space players meet to talk about the advancements and progress in exploration.

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

Early dispersal for quadrupedal cetaceans: amphibious whale from middle Eocene


Scientists have a relatively precise idea about where whales and their closest terrestrial relatives evolved more than 50 million years ago (early Eocene), thanks to the discovery of ancient cetacean fossils in India and Pakistan. Around 45 million years ago, four-legged whales (protocetids) gradually dispersed out of Asia, westward towards Africa and then reached the east coast of North America more than 41 million years ago.

Early dispersal for quadrupedal cetaceans: amphibious whale from middle Eocene
View of the locality Media Luna, where Peregocetus was discovered, in the Pisco Basin, coastal Peru,
at the beginning of the excavation, in November 2011 [Credit: O. Lambert]
Due to the relatively fragmentary fossil record on both sides of the North Atlantic, questions remain about the path they took to make it to the New World and their locomotion abilities. The newly described species Peregocetus pacificus, from middle Eocene (42.6 million years old) deposits of the fossil rich Pisco Basin (southern coast of Peru), provides some answers.


Lead author, Olivier Lambert, Royal Belgian Institute of Natural Sciences, Bruxelles,Belgium, presented the team's findings at this year's annual meeting of the Society of Vertebrate Paleontology held this year in Brisbane, Australia.

The importance of primitive whale, Peregocetus pacificus, lies in its completeness, location and age. This specimen represents the earliest skeleton of an amphibious whale from South America (and the whole Pacific).

Early dispersal for quadrupedal cetaceans: amphibious whale from middle Eocene
View of the excavation of the skeleton of Peregocetus in Media Luna,
with the Pacific Ocean in background [Credit: C. de Muizon]
"The discovery of this new quadrupedal whale by our Peruvian colleague Mario Urbina was a great surprise for all of us. When we saw that most of the forelimb and hind limb elements were preserved (even including a kneecap and phalanges displaying marks of small hooves!) we realized that this was a major find", Olivier Lambert stated. The specimen also includes mandibles, teeth, vertebrae, scapulae, pelvis, and many fore- and hind limb elements.


Sharing similarities with some western African protocetids, Peregocetus pacificus, supports the hypothesis that early quadrupedal whales crossed the South Atlantic from Africa to South America over 40 million years ago.

These early whales nearly attained a circum-equatorial distribution with a combination of terrestrial and aquatic locomotion abilities less than 10 million years after their origin in south Asia. Using large, most likely webbed feet with long toes, Peregocetus likely used its hindlimbs for underwater locomotion.

Early dispersal for quadrupedal cetaceans: amphibious whale from middle Eocene
Another view of the excavation of the skeleton of Peregocetus. Mario Urbina, the discoverer
of the locality and whale is on the right [Credit: G. Bianucci]
This discovery is not the first amazing fossil find from the Pisco Basin of Peru. "The Pisco Basin is an amazing region to study the evolution of marine mammals and other marine vertebrates. With rocks covering an interval of about 45 million years, we can follow the evolutionary history of many lineages, and interesting discoveries range from aquatic sloths and walrus-like dolphins to giant macroraptorial sperm whales and the oldest relatives of baleen whales", co-author Giovanni Bianucci says.

Source: Federation of American Societies for Experimental Biology [November 08, 2019]



* This article was originally published here

2019 November 12 NGC 3717: A Nearly Sideways Spiral Galaxy...



2019 November 12

NGC 3717: A Nearly Sideways Spiral Galaxy
Image Credit: ESA/Hubble & NASA, Processing: D. Rosario

Explanation: Some spiral galaxies are seen nearly sideways. Most bright stars in spiral galaxies swirl around the center in a disk, and seen from the side, this disk can be appear quite thin. Some spiral galaxies appear even thinner than NGC 3717, which is actually seen tilted just a bit. Spiral galaxies form disks because the original gas collided with itself and cooled as it fell inward. Planets may orbit in disks for similar reasons. The featured image by the Hubble Space Telescope shows a light-colored central bulge composed of older stars beyond filaments of orbiting dark brown dust. NGC 3717 spans about 100,000 light years and lies about 60 million light years away toward the constellation of the Water Snake (Hydra).

∞ Source: apod.nasa.gov/apod/ap191112.html

New fossil further resolves bauplan of extinct giant penguins


Penguins are descendants of seabirds that lost the ability to fly more than 60 million years ago in exchange for chasing the abundant food available in the ocean. New Zealand is a key area for understanding the diversity of the extinct penguins and has even revealed the existence of 'giant' penguin species (larger than living penguins).

New fossil further resolves bauplan of extinct giant penguins
Kawhia penguin reconstruction [Credit: Simone Giovanardi]


A new study describing a remarkably complete giant penguin skeleton from the Oligocene, Kawhia Harbour in the North Island of New Zealand was presented by Simone Giovanardi, Massey University Albany, Auckland, New Zealand, at this year's annual meeting of the Society of Vertebrate Paleontology held this year in Brisbane, Australia.

These giant penguins differed from their living descendants in the length of their front limbs and elongated beaks, perhaps suggesting differences in ecological roles when compared with living penguins. The preserved hindlimbs of the new North Island fossil are also significantly longer than all previously described specimens.


Giovanardi adds, "The Kawhia giant penguin is mostly complete and largely articulated in life position, which helps a great deal with reconstructing the relatively long and slender body." This specimen suggests a mixture of characteristics of an older body plan found in other Eocene-Oligocene giant penguins and the one found in the more derived giant penguin, Kairuku.

To date, most of the giant penguins found in New Zealand have been discovered in the South Island. This fossil was found in an Oligocene silty mudstone from the North Island of New Zealand and currently represents the most complete pre-Pleistocene vertebrate reported from this region. Giovanardi concludes by stating, "The North Island of New Zealand has its own paleontological tale to tell."

Source: Federation of American Societies for Experimental Biology [November 08, 2019]



* This article was originally published here

‘The Bridestones’ Prehistoric Stone Features, Todmorden, Calderdale, 10.11.19.I made a...

‘The Bridestones’ Prehistoric Stone Features, Todmorden, Calderdale, 10.11.19.

I made a return journey on a frosty morning in bright autumn sun.



* This article was originally published here

Fossil suggests apes, old world monkeys moved in opposite directions from shared ancestor


In terms of their body plan, Old World monkeys--a group that includes primates like baboons and macaques--are generally considered more similar to ancestral species than apes are. But a new study that analyzes the first well-preserved femur of Aegyptopithecus zeuxis, a common ancestor of Old World monkeys and apes, suggests that as far as locomotion goes, apes and Old World monkeys each evolved a way of moving that was different from the ancestral species as they adapted to different niches in their environments.

Fossil suggests apes, old world monkeys moved in opposite directions from shared ancestor
Artistic reconstruction of a group of Aegyptopithecus individuals on a tree during the Oligecene
[Credit: Lucille Betti-Nash (modified by Sergio Almecija)]
"Our study shows that Aegyptopithecus preserves an ancient hip morphology not present in living anthropoid primates," said Sergio Almecija, a paleoanthropologist and evolutionary biologist in the Division of Anthropology at the American Museum of Natural History who is first author on the study, which was published in Nature Communications this week. "As far as the hip is concerned, it seems that apes, humans, and Old World monkeys have all parted ways long ago--which would explain why they move around so differently today."


The fossil analyzed in the study was discovered in 2009 and is the most complete femur of Aegyptopithecus, a 15-lb (7-kg) likely tree-dwelling species that lived in Egypt about 30 million years ago, close to the time when hominoids (the group that includes apes and humans) split from the larger group that includes Old World monkeys. A well-preserved femur allowed researchers to glean details about the hip joint, a major anatomical region for inferring locomotion, using a combination of 3D morphometric analysis and evolutionary modeling.

Fossil suggests apes, old world monkeys moved in opposite directions from shared ancestor
Play session between adolescent male chimpanzee, Faustino, (Pan troglodytes schweinfurthii) and adolescent
male olive baboon (Papio anubis). Gombe Stream Research Center, Gombe National Park, Tanzania
[Credit: © Kristin J Mosher]
For the analysis, the authors compared the fossil bone to other extinct and modern species, including humans, chimpanzees, and Victoriapithecus and Homunculus (extinct Old World and New World monkeys, respectively). The evolutionary modeling analysis used in the study included a method that was developed to identify convergent evolution in anole lizards in the Caribbean, which have independently developed comparable niche-specific adaptations across various islands.


The results indicate that the ancestral hip joint is, from an evolutionary perspective, as far from the hip joint of modern Old World monkeys as from those of the great apes--suggesting that each group evolved a distinct way of moving as they specialized for success in different environmental niches.

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Bodowyr Prehistoric Burial Chamber, Anglesey, North Wales, 9.11.19.

Bodowyr Prehistoric Burial Chamber, Anglesey, North Wales, 9.11.19.



* This article was originally published here

DNA is only one among millions of possible genetic molecules


Biology encodes information in DNA and RNA, which are complex molecules finely tuned to their functions. But are they the only way to store hereditary molecular information? Some scientists believe life as we know it could not have existed before there were nucleic acids, thus understanding how they came to exist on the primitive Earth is a fundamental goal of basic research. The central role of nucleic acids in biological information flow also makes them key targets for pharmaceutical research, and synthetic molecules mimicking nucleic acids form the basis of many treatments for viral diseases, including HIV.

DNA is only one among millions of possible genetic molecules
Scientists have found there are likely millions of ways of storing biological information.
But why does biology do it the way it does? [Credit: Tokyo Institute of Technology]
Other nucleic acid-like polymers are known, yet much remains unknown regarding possible alternatives for hereditary information storage. Using sophisticated computational methods, scientists from the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology, the German Aerospace Center (DLR) and Emory University explored the "chemical neighbourhood" of nucleic acid analogues. Surprisingly, they found well over a million variants, suggesting a vast unexplored universe of chemistry relevant to pharmacology, biochemistry and efforts to understand the origins of life. The molecules revealed by this study could be further modified to gives hundreds of millions of potential pharmaceutical drug leads.


Nucleic acids were first identified in the 19th century, but their composition, biological role and function were not understood by scientists until the 20th century. The discovery of DNA's double-helical structure by Watson and Crick in 1953 revealed a simple explanation for how biology and evolution function. All living things on Earth store information in DNA, which consists of two polymer strands wrapped around each other like a caduceus, with each strand being the complement of the other. When the strands are pulled apart, copying the complement on either template results in two copies of the original. The DNA polymer itself is composed of a sequence of "letters", the bases adenine (A), guanine (G), cytosine (C) and thymine (T), and living organisms have evolved ways to make sure during DNA copying that the appropriate sequence of letters is almost always reproduced. The sequence of bases is copied into RNA by proteins, which then is read into a protein sequence. The proteins themselves then enable a wonderland of finely-tuned chemical processes which make life possible.

Small errors occasionally occur during DNA copying, and others are sometimes introduced by environmental mutagens. These small errors are the fodder for natural selection: some of these errors result in sequences which produce fitter organisms, though most have little effect, and many even prove lethal. The ability of new sequences to allow their hosts to better survive is the "ratchet" which allows biology to almost magically adapt to the constantly changing challenges the environment provides. This is the underlying reason for the kaleidoscope of biological forms we see around us, from humble bacteria to tigers, the information stored in nucleic acids allows for "memory" in biology. But are DNA and RNA the only way to store this information? Or are they perhaps just the best way, discovered only after millions of years of evolutionary tinkering?

"There are two kinds of nucleic acids in biology, and maybe 20 or 30 effective nucleic acid-binding nucleic acid analogues. We wanted to know if there is one more to be found or even a million more. The answer is, there seem to be many, many more than was expected," says professor Jim Cleaves of ELSI.

Though biologists don't consider them organisms, viruses also use nucleic acids to store their heritable information, though some viruses use a slight variant on DNA, RNA, as their molecular storage system. RNA differs from DNA in the presence of a single atom substitution, but overall RNA plays by very similar molecular rules as DNA. The remarkable thing is, among the incredible variety of organisms on Earth, these two molecules are essentially the only ones biology uses.


Biologists and chemists have long wondered why this should be. Are these the only molecules that could perform this function? If not, are they perhaps the best, that is to say, other molecules could play this role, and perhaps biology tried them out during evolution?

The central importance of nucleic acids in biology has also long made them drug targets for chemists. If a drug can inhibit the ability of an organism or virus to pass its knowledge of how to be infectious on to offspring, it effectively kills the organisms or virus. Mucking up the heredity of an organism or virus is a great way to knock it dead. Fortunately for chemists, and all of us, the cellular machinery which manages nucleic acid copying in each organism is slightly different, and in viruses often very different.

Organisms with large genomes, like humans, need to be very careful about copying their hereditary information and thus are very selective about not using the wrong precursors when copying their nucleic acids. Conversely, viruses, which generally have much smaller genomes, are much more tolerant of using similar, but slightly different molecules to copy themselves. This means chemicals that are similar to the building blocks of nucleic acids, known as nucleotides, can sometimes impair the biochemistry of one organism worse than another. Most of the important anti-viral drugs used today are nucleotide (or nucleoside, which are molecule differing by the removal of a phosphate group) analogues, including those used to treat HIV, herpes and viral hepatitis. Many important cancer drugs are also nucleotide or nucleoside analogues, as cancer cells sometimes have mutations that make them copy nucleic acids in unusual ways.

"Trying to understand the nature of heredity, and how else it might be embodied, is just about the most basic research one can do, but it also has some really important practical applications," says co-author Chris Butch, formerly of ELSI and now a professor at Nanjing University.


Since most scientists believe the basis of biology is heritable information, without which natural selection would be impossible, evolutionary scientists studying the origins of life have also focused on ways of making DNA or RNA from simple chemicals that might have occurred spontaneously on primitive Earth. Once nucleic acids existed, many problems in the origins of life and early evolution would make sense. Most scientists think RNA evolved before DNA, and for subtle chemical reasons which make DNA much more stable than RNA, DNA became life's hard disk. However, research in the 1960s soon split the theoretical origins field in two: those who saw RNA as the simple "Occam's Razor" answer to the origins-of-biology problem and those who saw the many kinks in the armour of RNA's abiological synthesis. RNA is still a complicated molecule, and it is possible structurally simpler molecules could have served in its place before it arose.

Co-author Dr. Jay Goodwin, a chemist with Emory University says "It is truly exciting to consider the potential for alternate genetic systems, based on these analogous nucleosides - that these might possibly have emerged and evolved in different environments, perhaps even on other planets or moons within our solar system. These alternate genetic systems might expand our conception of biology's 'central dogma' into new evolutionary directions, in response and robust to increasingly challenging environments here on Earth."

Examining all of these basic questions, which molecule came first, what is unique about RNA and DNA, all at once by physically making molecules in the laboratory, is difficult. On the other hand, computing molecules before making them could potentially save chemists a lot of time. "We were surprised by the outcome of this computation," says co-author Dr. Markus Meringer, "it would be very difficult to estimate a priori that there are more than a million nucleic-acid like scaffolds. Now we know, and we can start looking into testing some of these in the lab."

"It is absolutely fascinating to think that by using modern computational techniques we might stumble upon new drugs when searching for alternative molecules to DNA and RNA that can store hereditary information. It is cross-disciplinary studies such as this that make science challenging and fun yet impactful," says co-author Dr. Pieter Burger, also of Emory University.

The study is published in the Journal of Chemical Information and Modeling.

Source: Tokyo Institute of Technology [November 11, 2019]



* This article was originally published here

The Overview Effect

Observing Earth from space can alter an astronauts’ cosmic perspective, a mental shift known as the “Overview Effect.” First coined by space writer Frank White in 1987, the Overview Effect is described as a feeling of awe for our home planet and a sense of responsibility for taking care of it.

See Earth from the vantage point of our astronauts in these perspective-changing views:

Floating Free in Space

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Astronaut Bruce McCandless II used his hands to control his movement above the Earth during the first-ever spacewalk that didn’t use restrictive tethers and umbilicals. Fellow crew members aboard the space shuttle Challenger captured this image on Feb. 7, 1984, through windows on the flight deck.

Of his famous spacewalk, McCandless wrote in 2015: “My wife [Bernice] was at mission control, and there was quite a bit of apprehension. I wanted to say something similar to Neil [Armstrong] when he landed on the moon, so I said, ‘It may have been a small step for Neil, but it’s a heck of a big leap for me.’ That loosened the tension a bit.”

Earth Reflections

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Astronaut Tracy Caldwell Dyson looks through a window in the Cupola of the International Space Station (ISS). A blue and white part of Earth and the blackness of space are visible through the windows. The image was a self-portrait using natural light.

In a preflight interview for Expedition 23/24, Dyson said: “hands down, the best part about it is being able to look at that view every day and during the time frame we’ll be up there, hopefully, we’ll have a big bay window and much more opportunity to observe this beautiful planet.”

Taking in the View

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As astronaut Nick Hague prepared to conclude his six-month stay aboard the ISS, he shared this photo saying: “Today is my last Monday living on this orbiting laboratory and I’m soaking up my final views. The @Space_Station is truly an engineering marvel. #MondayMotivation." 

He and Expedition 60 and Soyuz commander Alexey Ovchinin of the Russian space agency Roscosmos​ completed a 203-day mission, spanning 3,248 orbits of Earth, and a journey of 80.8 million miles.

Earthrise

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On Dec. 24, 1968, Apollo 8 astronauts Frank Borman, Jim Lovell and Bill Anders became the first humans to witness the Earth rising above the Moon’s surface. 

 Anders, photographing the Moon from the right-side window, caught sight of the view, and exclaimed: “Oh my God, look at that picture over there! There’s the Earth comin’ up. Wow, is that pretty!”

The Blue Marble

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Besides Earthrise, the Blue Marble is probably the most famous image of Earth that NASA has produced. Taken by the Apollo 17 crew on their way to the Moon in 1972, the Blue Marble and other NASA imagery of Earth has been credited by some with helping to fuel the environmental movement.

For more information on the Overview Effect, check out this episode of Houston We Have a Podcast

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

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