Many Astronauts Never Recover all of their Bone Density after Returning to Earth

In his book, Endurance, astronaut Scott Kelly described the arduous task of readjusting to life on Earth after spending a year in space. As part of NASA’s Twins Study, Kelly lived and worked aboard the International Space Station (ISS) while his identical twin (astronaut Mark Kelly) remained on Earth. While the results of this study revealed how prolonged exposure to microgravity could lead to all manner of physiological changes, the long and painful recovery Kelly described in his book painted a much more personal and candid picture.

As it turns out, astronauts who spend extended periods in space may never fully recover. At least, that is the conclusion reached by an international team led by the University of Calgary after they assessed the bone strength of multiple astronauts before and after they went to space. They found that after twelve months of recovery, the astronaut’s bones had not regenerated completely. These findings could have significant implications for proposed future missions, many of which involve long-duration stays in space, on the Moon, and Mars.

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What is Einstein’s Theory of Relativity?

Einstein Lecturing
Albert Einstein during a lecture in Vienna in 1921. Credit: National Library of Austria/F Schmutzer/Public Domain

In the history of science and physics, several scholars, theories, and equations have become household names. In terms of scientists, notable examples include Pythagoras, Aristotle, Galileo, Newton, Planck, and Hawking. In terms of theories, there’s Archimede’s “Eureka,” Newton’s Apple (Universal Gravitation), and Schrodinger’s Cat (quantum mechanics). But the most famous and renowned is arguably Albert Einstein, Relativity, and the famous equation, E=mc2. In fact, Relativity may be the best-known scientific concept that few people truly understand.

For example, Einstein’s Theory of Relativity comes in two parts: the Special Theory of Relativity (SR and the General Theory of Relativity (GR). And the term “Relativity” itself goes back to Galileo Galilee and his explanation for why motion and velocity are relative to the observer. As you can probably tell, explaining how Einstein’s groundbreaking theory works require a deep dive into the history of physics, some advanced concepts, and how it all came together for one of the greatest minds of all time!

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If Planet 9 is out There, Here's Where to Look

Illustration of the hypothetical Planet 9. Credit: R. Hurt/IPAC, Caltech

There are eight known planets in the solar system (ever since Pluto was booted from the club), but for a while, there has been some evidence that there might be one more. A hypothetical Planet 9 lurking on the outer edge of our solar system. So far this world has eluded discovery, but a new study has pinned down where it should be.

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Fantastic Visualization Shows What Would Happen if you Dropped a Ball Across the Solar System

Screen shot of ball drop across the solar system video.

Summertime means it’s time to play ball! But what would it be like to play ball on various locations across our Solar System? Planetary scientist Dr. James O’Donoghue has put together a fun animation of how quickly an object falls on to the surfaces of places like the Sun, Earth, Ceres, Jupiter, the Moon, and Pluto.

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A new Approach Could Tease out the Connection Between Gravity and Quantum Mechanics

Credit: University of Nottingham

In physics, there are two main ways to model the universe. The first is the classical way. Classical models such as Newton’s laws of motion and Einstein’s theory of relativity assume that the properties of an object such as its position and motion are absolute. There are practical limits to how accurately we can measure an object’s path through space and time, but that’s on us. Nature knows their motion with infinite precision. Quantum models such as atomic physics assume that objects are governed by interactions. These interactions are probabilistic and indefinite. Even if we constrain an interaction to limited outcomes, we can never know the motion of an object with infinite precision, because nature doesn’t allow it.

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Magnetic Fields Help Shape the Formation of New Planets

In all of scientific modeling, the models attempting to replicate planetary and solar system formation are some of the most complicated.  They are also notoriously difficult to develop.  Normally they center around one of two formative ideas: planets are shaped primarily by gravity or planets are shaped primarily by magnetism.  Now a new theoretical model has been developed by a team at the University of Zurich (UZH) that uses math from both methodologies to inform the most complete model yet of planetary formation.

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Health Issues From Spaceflight Might Originate in the Mitochondria

Credit: NASA

It’s not easy living and working in space for extended periods of time. As NASA’s Twins Study illustrated, microgravity takes a toll on human physiology, which is followed by a painful transition back to normal gravity (just ask Scott Kelly!) Aside from muscle and bone degeneration, there’s diminished organ function, effects on cardiovascular health, the central nervous system, and “subtle changes” on the genetic level.

Until now, the biggest unanswered question was what the underlying cause of these physical impacts was. But after reviewing all of the data accumulated from decades of research aboard the International Space Station (ISS) – which included the Twins Study and DNA samples taken from dozens of astronauts – an international team of researchers came to the conclusion that mitochondria might be the driving force for these changes.

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Weekly Space Hangout: September 30, 2020, Dr. John Kiss Discusses the Growth of Plants in Space

This week, we welcome Dr. John Kiss from the University of North Carolina, Greensboro (UNCG). Tonight, Dr. Kiss will be discussing the sensory physiology of plants in space research, including the effect of Mars’ levels of gravity on plant development.

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Gravity is tested down to a scale smaller than the thickness of a human hair

Gravity was the first force of nature to be realized, and in the centuries since we first cracked the code of that all-pervasive pulling power, scientists have continually come up with clever ways to test our understanding. And it’s no surprise why: the discovery of a new wrinkle in the gravitational force could open up vistas of new physics, and maybe even the nature of reality itself.

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Astronomy Cast Ep. 503: Gravity Mapping

The Earth looks like a perfect sphere, but down here on the surface we see that there are mountains, rivers, oceans, glaciers, all kinds of features with different densities and shapes. Scientists can map this produce a highly detailed gravity map of our planet. And it turns out, this is very useful for other worlds too.

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