Living in Space Is Tough on Your Body

     Living in space, even just visiting for a few weeks or months, is tough. The environment out there can be deadly. Radiation will kill you slowly, and the lack of oxygen will kill you quickly. But those conditions can be mitigated. We build radiation protection into our spacecraft, and we carry oxygen, food, and water to keep us alive. But one dangerous aspect of space can’t be controlled: the lack of gravity. We currently have no effective artificial gravity.

You might have seen videos of astronauts floating and spinning in their spacecraft or sucking up blobs of water from mid-air. It may look like fun, but there are long-term consequences of living for extended periods with no gravity. 

Lack of gravity causes unexpected and sometimes bizarre changes in the human body. Astronauts who stay in space for too long develop puffy heads and bird-like, thin legs. On Earth, gravity pulls your bodily fluids down to your legs, but in space, that doesn’t occur. Your heart, for example, can more easily pump blood up to your head and away from your legs. As much as a gallon and a half more of various fluids can collect in and near an astronaut's head. Although that problem disappears rather quickly after returning to Earth’s gravity, NASA is working on ways to alleviate brain and eye strain during the time spent in space.

As their bodily fluids move toward the head of an astronaut, they can develop neuro-ocular syndrome. The optic nerve swells due to greater fluid pressure, causing the back of the eye to flatten. According to NASA, 70% of astronauts on the ISS experience some amount of swelling in the back of their eyes. This may cause blurry vision and the occasional headache. While glasses can help alleviate this, researchers are concerned about how this might affect astronauts on long-duration flights, such as a 1000-day trip to Mars.

An astronaut onboard teh ISS her eyes. Credit NASA

On Earth, your bones and muscles must constantly work to keep you upright against the pull of gravity. With a lack of gravity, that’s no longer necessary, and astronauts lose bone and muscle mass. NASA has developed exercises for astronauts to do while in space, and although the effect reverses itself once they return to Earth, doctors are again concerned about long flights to Mars.

In space, your heart doesn’t need to work so hard pumping blood “uphill” to your brain. As a result, the hearts of astronauts shrink a bit and become more spherical. Upon returning to Earth’s gravity, they can have difficulty maintaining normal blood pressure when standing. Again, this effect is reversed on Earth, but long flights to Mars may be quite problematic for returning astronauts.

As the head swells and more fluids enter the astronaut’s brain, it can shift a bit in their skull. This can lead to disorientation and issues with balance and coordination. That effect fades with time in a weightless environment.

I, for one, would be willing to deal with those issues for a chance to explore Mars, but NASA must consider the health and safety of its astronauts and is still seeking solutions to these problems.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

Does Tryptophan in Turkey Make you Sleepy? Blame the Cosmos

After your Thanksgiving feast, did you crash? Many people do, and it has been blamed on tryptophan, an amino acid in turkey. It’s possible you have the cosmos to blame for that.

According to an internet search, “Tryptophan is an essential amino acid the body uses to make proteins, the neurotransmitter serotonin, and the sleep-related hormone melatonin. It is not produced by the body, so it must be obtained through diet from foods like turkey, chicken, nuts, and soy.” This, some people claim, is why you feel sleepy after a Thanksgiving meal that includes turkey.

Astrobiologists, specialists who seek evidence of life elsewhere, and biologists who study the origins of life on Earth suggest several ways life might have started here. One idea is known as panspermia. Panspermia says that life on Earth was seeded from space, most likely by organic molecules delivered to Earth via asteroids, comets, or meteorites, which carried these molecules.

Earth spacecraft have returned samples from two asteroids, Ryugu and Bennu. They have found 90 amino acids, including 14 of the 20 used by life on Earth. In addition, they have found all five of the bases, adenine, guanine, cytosine, thymine, and uracil, which make up our DNA.

The asteroid Bennu. Credit NAS/JPL/University of Arizona

One of the amino acids on asteroid Bennu was tryptophan. José Aponte is an astrochemist at NASA's Goddard Space Flight Center who coauthored a study on the sample returned from Bennu. On finding that sleep-inducing molecule on Bennu, he said, "Finding tryptophan in the Bennu asteroid is a big deal, because tryptophan is one of the more complex amino acids, and until now it had never been seen in any meteorite or space sample."

Many biologists and other scientists who study the formation of life on Earth believe that it rose independently here. But the delivery of important organic and other biologically important molecules to our planet from space must surely have played a role. Before you say life here didn’t come from the stars, remember that most of the molecules in our bodies were formed in stars, so we are literally star dust.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.

Is a Primordial Black Hole Aiming at Us?

 Many mysteries about our universe haunt astronomers.  Among those, one of the most perplexing is what they call “dark matter.” By studying the gravitational interactions and motions of galaxies, astronomers learned that most of the matter in our universe, about 86%, is composed of stuff that has no connection to light. It doesn’t emit, reflect, or absorb any type of electromagnetic radiation, including light, hence the moniker dark matter.

Astronomers know it’s there. The evidence for it is overwhelming. Galaxies rotate so fast that they should fly apart unless there is a lot more mass than can be accounted for in stars, planets, gas clouds, and all the other stuff we can see. But they have no idea what it is.

Some astronomers have suggested that so-called primordial black holes (PBH) may be responsible for dark matter. Black holes are the extreme members of the cosmic zoo. Their gravity is so strong that nothing, not even light, the fastest thing in the universe, can escape. Normal black holes form when giant stars explode as a supernova, and the remaining core becomes so compressed by gravity that it collapses into a black hole. These are typically 5 to 10 times the mass of our sun. Black holes also do not emit or reflect any light.

PBHs form quite differently. When the universe began in the Big Bang, the density of matter was unimaginably high. Particles would constantly collide, sometimes sticking together. Usually, they would break apart in another collision a tiny fraction of a second later. Some areas of this infant universe were so dense that matter could clump together so tightly that they could form black holes millions of times smaller than a single proton. They may contain no more mass than a moon, a mountain, or even an elephant. Once formed, the extreme gravity holds them together regardless of how many collisions they may experience.

PBHs may well exist in such numbers that they could fill space. They might well be responsible for most or even all the dark matter that we know exists out there. Sarah Geller, a theoretical physicist at the University of California at Santa Cruz, co-authored a study of PBHs. They wondered how often one might pass through our solar system. "If there are lots of black holes out there, some of them must surely pass through our backyard every now and then," Geller said.

A primordial black hole interacting with Earth. Credit ESO/M Kornmesser

The researchers wondered "what might happen if a black hole punched through Earth's crust, or passed through our atmosphere, or left a crater on the moon," Geller said. "We even asked ourselves what would happen if one of these tiny black holes hit a human." After crunching the numbers, they realized that the chances of one hitting something as small as a person, or even our planet, were extremely tiny.

"We started thinking about the very precisely measured orbits of objects in the solar system," Geller said. "They could produce wobbles in the orbits of objects in the solar system that are big enough for us to measure." They estimate that one could pass through the inner parts of the solar system once every decade or so. The researchers aren’t claiming that PBHs exist, that they make up any of the dark matter, or that they are in or have passed through the solar system. But if they do exist in sufficient numbers that some or many have visited our planets, we can detect their gravitational pull.

Just to ease your mind, a separate study found that even if a PBH passed through your body, they are so tiny and so fast, they would likely cause no noticeable effect on your body.

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.

It's Time to Protect Extraterrestrial Locations that Might Support Life

 In 1972, Christopher Stone, a legal scholar at the University of Southern California, wrote a paper titled “Should Trees Have Legal Standing?” Although it took a few decades for the idea to catch on, it marked the beginning of the Rights of Nature movement. The United Nations has recently referred to it as the fastest-growing legal movement of the 21st Century.

Previously, a person or a group had to prove harm from some other person or company disturbing the environment before any legal action was taken. The Rights of Nature charter allows a person or a group to directly represent some aspect of nature that has rights of its own. It is similar to the legal cases in which parties, like children, can’t represent themselves, yet need legal protection. Some countries have put such protections in local and national laws, and some even in their constitutions.

Now, three scientists from the United Kingdom, an astrobiologist, an earth scientist, and a legal scholar, published a space policy paper saying such protections should extend to any extraterrestrial life we may discover and the environments in which they exist or may have existed.

We currently have probes on the surface of Mars seeking conditions, past or present, which might support life, as well as any living things that might currently exist there. Some moons, notably Europa, which orbits Jupiter, and Enceladus, a moon of Saturn, have organic materials that may well indicate the presence of living microbes there. Even a few asteroids exhibit some of the conditions that might be explained by extinct microbial life forms.

Enceladus, a moon of Saturn, is venting water and organic molecules.

Europa, a moon of Jupiter, possesses a 100-mile-deep ocean with organic molecules.

On our planet, despite this movement, we too often destroy natural environments, leading to a loss of habitat for species living there. This is one of the major causes of the extinction of flora and fauna on Earth. These scientists are advocating that we not do the same to extraterrestrial locations where life, however simple, might, or may in the future, exist.

In their Space Policy paper, the three chronicle many of the successes of the Rights of Nature movement. They say we need to extend this “circle of Rights beyond Earth” and suggest that environmental groups join forces with organizations that govern space activities, such as the United Nations Office for Outer Space Affairs.

We don’t always have a great track record of protecting species on Earth. This paper urges that we do not create the same sorts of environmental destruction in extraterrestrial locations that currently support or once may have supported any form of life.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.

What Do We Do When We Discover Extraterrestrial Aliens?

 We humans have numerous scientific activities currently involved in the search for extraterrestrial intelligence (SETI). These include observations of numerous star systems looking for radio signals. as, for example, radar signals like those our airports send into space. The spacecraft we have sent to study the other planets and moons in our solar system have found intriguing hints of microbial life. However, we have yet to find any concrete proof of any life anywhere other than on Earth.

The James Webb Space Telescope can study planets orbiting other stars, searching for potential signs in their atmospheres that might indicate technological presence. Again, we have not yet found any such signs, only possible hints.

NASA's James Webb Space Telescope. Credit NASA

Most astronomers and other scientists believe it to be just a matter of time before such discoveries are made. What should we do then? Kate Genevieve from the Astro Ecologies Institution led a study that included 13 other researchers from various universities. They believe that previous preparation efforts, including the most recent guidelines, which were developed in 1989 (pre-World Wide Web), are outdated.

The study authors believe we need a detailed plan. NASA and the global scientific community, they say, should prepare for the moment humanity detects signs of extraterrestrial intelligence in the internet age. The research paper states that "a technosignature detection will trigger a complex global process shaped by uncertainty, misinformation, and multiple ideological stakeholders."

Getty Images

One area of preparation that the study says needs much more research on is how to understand minds that think radically differently from the way humans do. We need to develop "Other Minds" paradigms. Techniques the paper claims we need include studying whale songs and bird navigation to understand communication patterns in non-human entities. Whales, dolphins, and birds represent some of the most intelligent non-primate species on Earth, making studying them a good way to start learning how other intelligences think.

The authors also state that we need research studies on “the psychological, social, and global dynamics of post-detection scenarios.” They suggest analyzing science fiction to learn how different cultures imagine alien contact, giving us insight into how Earthlings as a whole might react, and providing an understanding of expectations and fears.

The team members strongly emphasize the need for strong international coordination of efforts and programs now. A fractured response by different nations could well lead to severe problems.

The paper doesn’t say that detection of extraterrestrial intelligence will occur soon, but it emphasizes that with new technologies like the Webb Space Telescope and the soon-to-be-operational Vera C. Rubin Observatory, such discoveries could come soon. The researchers feel we need to do much more before aliens come calling.

 

    Each month, I write an astronomy-related column for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

     This is reprinted with permission from the Oklahoman and www.Oklahoman.com.

Can Aliens Receive Our Radar Transmissions?

  

One of the most fundamental questions that we as a civilization might ask concerns the possibility that other intelligent beings may also inhabit our galaxy. On November 16, 1974, a group of scientists led by Frank Drake and Carl Sagan sent a message towards a large star cluster in the constellation of Hercules. At a distance of 13,000 light years, the message is still a long way from getting there. That event is considered the beginning of our search for other civilizations.

 

Frank Drake, credit SETI Institute.                     Carl Sagan, credit NASA Science

SETI stands for Search for Extra-Terrestrial Intelligence. The two most active organizations doing this are the SETI Institute and the Breakthrough Listen program. Both primarily use sophisticated radio telescopes to search for artificial radio signals from other planets that could support life. The thinking behind these projects is that any other intelligent civilization is likely to use radio signals for communication and detection.

The Allen Telescope Array, used by the SETI Institute.

The Very Large Array radio telescopes used by Breakthrough Listen. 

We humans use radio for these very purposes. Civil and military airport radar represents our most powerful radio signals. We’ve been using this technology since World War 2, and today’s radars are far more powerful and sophisticated. They are so powerful that they can be detected by any civilization with radio telescope technology at the same level as our SETI searches use.

Ramiro Saide, a Ph.D. student at the University of Manchester, led a research project to calculate how far away our radar facilities could be detected by civilizations at least as advanced as us. Our radio telescopes are capable of detecting a signal like what we emit from our airport radars from 200 light years away. There are more than 120,000 stars within 200 light-years of Earth. Although we currently have no evidence that any of those stars are home to intelligent aliens, we do know that they likely have some 200,000 or more planets that orbit them. Most of those aren’t capable of supporting life as we know it, but some may well be able to.

Saide said of the study that our radar signals would appear “clearly artificial to anyone watching from interstellar distances with powerful radio telescopes. These military signals can appear up to a hundred times stronger from certain points in space, depending on the observer’s location. Our findings suggest that radar signals – produced unintentionally by any planet with advanced technology and complex aviation system – could act as a universal sign of intelligent life.”

While our efforts to detect other civilizations have not yet provided any absolute proof of their existence, at least we know that our equipment could detect their radar emissions. The SETI Institute and Breakthrough Listen will continue to monitor the skies for any neighbors we might have.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.

Making Distances in Space a Bit Easier to Imagine

 Warning to my readers: I’ll be using some big numbers in this article. Hopefully, I have made it as painless as possible.

Distances to objects in space from Earth are, well, astronomical. The Moon is 239,000 miles away. We’d have to travel 93,000,000 miles to reach the sun. That may seem like a great distance, but the next closest star, Proxima Centauri, is 22,876,214,400,000 miles away. Proxima Centauri is the closest of a three-star system known as Alpha Centauri. Using miles as a distance measure in space is quite impractical. The numbers get very big very quickly. Instead, we use light-years, the distance light travels in one year.

Artist's rendering of the Alpha Centauri three-star system. Credit NASA's Goddard Space Flight Center Conceptual Image Lab

Light travels at the fastest possible speed, moving through space at 186,000 miles per second. That’s 669,600,000 miles/hour or 5,865,696,000,000 miles/year. We call that distance, 5,865,696,000,000 miles, one light-year. Proxima Centauri is 4.25 light-years away, which is easier to write.

Let’s think about those astronomical distances in terms we can more easily visualize. Imagine one light year equals one mile. We all have a good understanding of how long a mile is. On this scale, light travels 0.002 inches per second. That’s a big change from the actual speed of light. The moon is 1.3 light seconds from Earth, or 0.0026 inches with this new light-year. We would orbit the sun, 8.3 light minutes away, from a distance of just under an inch. Proxima Centauri is 4.25 light years away, which now equates to 4.25 miles. Now it’s a lot easier to imagine these distances.

The fastest speed that any of our spacecraft has ever flown is the Parker Solar Probe. It used multiple gravity assists from Venus to get it close to the sun. It orbits so close to the sun that it passes through the sun’s outer atmosphere. In order to orbit the sun that closely, it has to move fast, achieving a maximum speed of 430,000 miles per hour. That’s really moving. But scaled to our new light speed of one mile per year, that corresponds to a mere 0.00064 miles per hour. At that speed, it would take 1,557 years to reach Proxima Centauri. Even in this shrunken universe, our Milky Way galaxy is 100,000 miles across, and our closest comparably large galactic neighbor, the Andromeda Galaxy, is still a mind-numbing 2,537,000 miles away.

As you can see, our universe is so incredibly large, even when shrunk by a factor of 5,865,696,000,000, it’s still huge beyond easy comprehension.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.