A Refinement for SETI

 SETI is a branch of astronomy that seeks direct detection of alien life. We can currently only visit the other planets of our solar system, and none appear to have any intelligent beings on them. Therefore, SETI, which stands for Search for Extraterrestrial Intelligence, looks for radio signals from other civilizations. While we have detected a few signals we can’t yet explain, they were only one-time events and likely come from some as-yet unknown natural physical process.

We have been broadcasting our own radio signals into space for about 100 years, so any civilization within 100 light-years of us could potentially detect our existence. With our current technology, we can detect any civilization with our own level of radio signals from twice that distance. A civilization with more advanced radio technology might be detected by us from even farther away.

At our current level of technology, it is nearly impossible for us to determine if any signal we might receive originates from the star itself or an orbiting planet. The separation is generally too small for our equipment to distinguish between the two. Any signal we do detect is far more likely to be caused by a natural process in the star and not from a civilization on an orbiting planet unless we can determine it came from the planet.

The Beta Pictoris system with Beta Pictoris b. Credit ESO

The star Beta Pictoris lies only 63.4 light-years from us. In 2008, astronomers discovered it has a planet, Beta Pictoris b. It is a massive gas giant planet, ten times more massive than Jupiter. Recently, astronomers discovered a radio signal emanating from that star system, but they couldn’t tell if it came from the star or its orbiting planet. A team of scientists led by Kevin Ortiz Ceballos at the Center for Astrophysics, Harvard & Smithsonian found a clever way to determine the source using the MeerKAT Radio Telescope Observatory in Australia.

MEERKAT Observatory. Credit Universiay of Manchester

They overlaid a map of distant quasars, the active black holes at the center of virtually all galaxies, over the Beta Pictoris system. Using the well-established positions of the quasars, they could determine that the radio emissions came from a point just beside the star, proving the emissions came from the planet. They determined the signals resulted from aurora, like our Northern Lights, but much stronger due to Beta Pictoris b’s much more powerful magnetic field.

Suzanne Aigrain, a professor of astrophysics at the University of Oxford, who was not involved in the study, said, "Astronomers have been looking for radio signals from exoplanets for some time. There have been tentative, indirect detections before, but this is the first truly convincing direct detection, and it hopefully paves the way for many more."

We didn’t discover aliens, but we have found a way to distinguish whether any signal we do detect comes from a star or one of its planets, and therefore possibly from an alien civilization.

  

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.

 

The Microbes We Transport With Us to Mars May Become Killers

 In the H. G. Wells book “War of the Worlds,” Martians attack Earth when their planet is becoming uninhabitable due to a loss of water. Their technology is superior to ours, and we humans were not able to stop them. Finally, the assault stopped, and all the Martians died. Not because we defeated them, but because they succumbed to fatal diseases caused by Earth’s bacteria, which their immune systems couldn’t cope with.

NASA and SpaceX want to land a permanent colony on Mars. We know that planet can’t support humans directly. We will have to bring our environment with us, creating structures that can protect us from the harsh environment there.

Wherever humans go, we take with us a load of stowaways in the form of microbes, both in our bodies and on all of our equipment. Even our unmanned spacecraft are contaminated with microbes, no matter how carefully we try to keep them clean. When humans do finally reach Mars, these microbes will arrive with us.

Soil Microbes. Credit Northwest National Laboratory

Radboud University PhD candidate Tommaso Zaccaria wondered whether terrestrial micro-organisms could survive in other locations in the solar system. In space, an astronaut’s immune system becomes compromised. Several conditions of space travel contribute to that, such as the lack of a normal day-night rhythm, poor diet, disrupted gut function, DNA damage from radiation, limited social interaction, and confinement in a small space. Zaccaria asked how the microbes we carry with us to Mars will affect our health. He wondered if any microbes that survive the trip might pose a danger to humans.

Using a simulated Martian surface, he compared the microbes’ effects on our lungs with those of Earth sand. Zaccaria said, “We observed that material from Mars damages the protective layer of the lungs and causes infections. Earth material did not.”

Martian Colony. Credit NASA and JPL.

He then studied several human pathogens, including the bacteria that causes pneumonia in these same simulated Martian conditions. The bacterial cells shrank in Mars conditions, but some did survive. Human immune cells in our blood respond less strongly to shrunken pathogens. At least some pathogens we will take with us could become even more virulent on Mars.

Because of their simplicity, micro-organisms evolve far more quickly than we do. In the new conditions bacteria will find on Mars, they will likely rapidly mutate into new variants that could easily lead to a pandemic for which we have no defense.

The first human colonists traveling to Mars will face a daunting task just surviving the trip.  And once they get there, they may have to deal with a far more challenging threat from the microbes they will bring with them. And like the Martians of H. G. Wells’s imagination, they may be our own undoing on Mars.

 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.

Turning Night Into Day

      Have you ever stood out in your backyard or a park after dark and look up at the stars? Have you ever been in a really dark location and stared in wonder at the beauty of our Milky Way galaxy as its hazy band stretches across the sky? If one company has its way that may not be something you can do for much longer.

The Federal Communications Commission (FCC) has granted permission for a company called Reflect Orbital to put a giant space mirror, called Earendil-1 in orbit. The company’s plan is to use the giant mirror to reflect sunlight down to Earth for “extra solar energy and area-wide lighting” at night. Their ultimate goal is to place 50,000 of these in Earth orbit by 2035. They claim the nighttime lighting could be used for agriculture, emergency response, and other industrial sectors.

Artists conception of sunlight-refelcting space mirror. Credit Reflect Orbital

But what they don’t talk about are all the negative effects critics claim will result from this activity. Such intense lighting at night is harmful for human health, ecosystems, aviation and astronomy. The light could disrupt circadian rhythms of plants, animals and humans. The satellites will need to repointed every four minutes. As it redirects the light, it could temporarily blind pilots and drivers on the ground, possibly causing car wrecks and plane crashes which would endanger people.

When asked why the FCC would allow such a project with potentially fatal consequences, it responded “the risks of harm raised on the record regarding Reflect Orbital’s solar reflector are unrelated to the Commission’s role in authorizing use of radiofrequency spectrum.” Basically, the FCC said they don’t consider dangers to humans, ecosystems, or the safety of airplanes or drivers when making their decisions.

 A NASA Space News article describes many of the problems with artificial light at night (ALAN). The article states that ALAN disrupts circadian rhythm of many different animals. It has been documented extensively in insects, migratory birds causing injuries and fatalities through collision in flight and disruption of navigation during migration, and marine ecosystems, including coral spawning and sea turtle hatchling orientation, among other negative effects.

 Thousands of these space mirrors brightening the night sky could spell the death of astronomy. Ground based telescope would no longer be able to see much in our “night” sky, and the huge number of such satellites in space may render many orbiting astronomical instruments useless.

Starlink Satellite Train. Credit Starlink Insider

Astronomers now have to account for the thousands of satellites already in orbit that interfere with delicate observations. The addition of thousands more very bright satellites could end visual astronomy altogether. The star map shows the night sky for this month. No planets will be visible at chart time, but if you can get to a dark location, you can marvel at the hazy band of the Milky Way, a sight that may become rarer in just a few years.

 

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.

Rocks In Space

 You have probably seen a shooting star while outside at night. Maybe you have also witnessed a meteor shower when numerous shooting stars occur over the course of the night. They represent a tiny piece of our solar system falling to Earth. Sometimes, many meteors can be seen over the course of a few hours. We call these meteor showers.

 Perseid meteor shower which peaks in Mid-August. Credit NASA/Preston Syches

Our solar system consists of eight planets. Well, some people, myself included, believe that Pluto should still be considered a planet, and there is evidence that another one orbits far from the sun but has yet to be discovered. Along with those planets, there are five objects that astronomers refer to as “dwarf planets” orbiting the sun. That’s what Pluto was demoted to in 2006.

Our sun is also orbited by thousands of asteroids, smaller rocky objects left over from the formation of the planets. Many of these orbit between Mars and Jupiter in a region called the Asteroid Belt. In the region beyond Neptune lies an area called the Kuiper Belt, a flattened disc   of millions of comets, objects containing mostly frozen gases along with a bit of rocky material. Even more comets exist in a vast shell surrounding our solar system.

The asteroids in the asteroid belt occasionally collide, creating a large number of smaller bits of rock, which astronomers call meteoroids. Being so small, they are easily affected by the gravity of other bodies orbiting the sun and scatter throughout the inner solar system.

Artist's view of the asteroid belt. Credit NASA

If one comes close to our planet, Earth’s gravity reels it in. These meteoroids enter our atmosphere at tremendous speeds, often exceeding 25,000 miles per hour. At such speeds, friction with our air creates so much heat that the air itself begins to glow. That glowing streak of light is known as a meteor or a shooting star. The tiny bit of rock itself is far too small to be seen, typically being not much larger than a grape.

The heat created by the meteoroid’s passage through our atmosphere will usually disintegrate it into fine dust. If the meteoroid creating the shooting star is large enough to survive to the ground, we call it a meteorite. Scientists estimate that a few hundred tons of meteoritic material fall to Earth each day, much of it in the form of very fine dust from disintegrated meteoroids. Many larger pieces fall as meteorites. These are highly prized by scientists because they help us understand how our solar system formed. Collectors pay for meteorites. The rarest meteorites come from the Moon and Mars. The largest known Martian meteorite sold for 5.3 million dollars.

How does a hunk of Mars fall to Earth? Asteroids occasionally strike Mars. Due to its smaller gravity, fragments can be blasted into space. Rarely, such a piece of Mars eventually falls to Earth. There are only some 400 known Martian meteorites found on Earth.

     Meteorites aren’t the only things that fall from the sky. Along with mundane weather phenomena like rain, hail, sleet, and snow, some surprising things have fallen to earth. Large numbers of live and dead animals occasionally fall. People have found golf balls, coins, and even sugar crystals that fell from the sky. Some objects, like meteorites, fall all the way from space. You can learn about these and many more of the strange objects that have fallen to the ground in my book “When the Sky Falls, Duck.” This book won a recent Non-Fiction Book of the Year Award. It is available from Barnes and Noble’s online store at BN.com.

 

    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.

Weird Rocks on Mars

 Perhaps you have seen videos or pictures of rocks very carefully stacked as an artistic work. They may even look impossibly balanced. 

Balanced Rocks. Wikipedia.

    Or you may have seen so-called balancing rocks, with one huge boulder precariously sitting on a tiny point on top of another large boulder. These terrestrial balancing boulders weren’t created by humans, but rather by wind and water erosion.

Balancing rocks formed by erosion. Nevada Traveler

Scientists studying the images and data sent back by the Perseverance rover on Mars found an unusual sight. It appears to be three or four rocks neatly stacked one on top of the other. It rather resembles a hamburger with an oversized patty or an undersized bun. The patty in the middle looks as if it broke because the bun was too small. The rocks fit together so perfectly that they look as if they were stacked by human hands. Scientists attribute the stacked appearance to wind erosion of a single rock. Some say it looks more like water erosion, but there hasn’t been any surface water on Mars for perhaps 3 billion years.

Staxcked rocks on Mars. NASA/JPL/Cal Tech

This find by Perseverance isn’t the only weird rock discovered on the surface of Mars. Perseverance photographed a rock with stripes or striations on it. It looks to the scientists studying the images and data from the rover to be volcanic in origin. It appears to have fallen from a layer of similar rock farther up the slopes of Jezero crater that Perseverance has been exploring since it landed. Athanasios Klidaras, a PhD student in planetary science at Purdue University, wrote in a statement on NASA's Science website, "Our knowledge of its chemical composition is limited, but early interpretations are that igneous and/or metamorphic processes could have created its stripes."

Stripped rock on Mars. NASA/JPL/Cal Tech

One of the stranger rocks Perseverance imaged the researchers nicknamed "St. Pauls Bay." It is covered with hundreds of millimeter-sized, dark grey spheres. Some of them have tiny pinholes in them. Scientists believe these spheres to be concretions formed by the interaction of groundwater circulating through pores in the rock. It is also possible they were formed by volcanic activity. "Each of these formation mechanisms would have vastly different implications for the evolution of these rocks, so the team is working hard to determine their context and origin," the mission team said in the statement. "Placing these features in geologic context will be critical for understanding their origin and determining their significance for the geological history of the Jezero crater rim and beyond."

Studded rock on Mars. NASA/JPL/Cal Tech

While Perseverance’s main job is to look for evidence of past life on Mars, which it has yet to find, it is finding that the environment was once, long ago, conducive to life. It may yet find fossilized bacterial remains like those we have found on our planet.

 

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.

Surprising Things We Have Launched to Space

 We have sent a lot of stuff to space. Along with more than 640 people, we’ve launched numerous non-human astronauts to space, including dozens of primates, over 30 Soviet dogs, mice, cats, jelly fish, tortoises, fish, and spiders. In 1947, the U.S. launched a group of fruit flies on a suborbital flight using a captured German V-2 rocket to study the effects of radiation. While they didn’t go into orbit, they were the first living things to reach space. We humans have launched more than 25,000 satellites into Earth orbit or beyond. Of those, nearly 17,000 still remain in orbit, but only around 14,200 remain operational.

Ham, the chimpanzee, launched in 1961. Credit NASA

All the above were launched to study the feasibility and safety of space flight or to study the effects of long-term weightlessness. But along with animals and humans, plus communication and weather satellites, Earth resources, and other scientific satellites, we have launched a few stranger items into space.

Several space missions have included small pieces of the Wright Flyer, the first airplane. On one such space flight, bits of the plane rode with Apollo 11 to the Moon’s surface. Those missions demonstrated how human flight has come full circle.

Several companies now offer “space burials,” sending cremated remains into space. Elysium Space is one of several such companies. With them, you can launch a small portion of one’s remains sealed in a small capsule. They offer such services as a “Shooting Star” memorial in which the remains are released into orbit where the small capsule falls back to earth, burning up like a shooting star. Or you might opt for a “Lunar Memorial” in which the remains are delivered to the Moon’s surface. In 1997, the first space burial involved sending remains of Gene Roddenberry, the creator of Star Trek, to enjoy the final frontier. Elysium claims the remains of more than 640 people have flown in space.

Tesla launched Elon Musk’s personal cherry red Tesla Roadster with a dummy astronaut sitting at the wheel in 2018. The car with “Starman” was sent into a solar orbit that took it out to the distance of Mars, and it still floats out there.

A significant part of NASA’s mission involves educating and exciting kids about space. NASA knows kids like dinosaurs, so in 1985, they launched some bones from a Maiasaur (“Good Mother”) dinosaur to be used for school educational programs. That was the first of multiple dinosaur fossils launched to space. Objects flown in space can sell to collectors for huge amounts of money, so some dinosaur fossils were simply flown to create a greater selling price.

Lego makes popular kid’s building block toys. NASA sent a Lego set to the International Space Station, hoping that such missions will inspire kids to consider fields in aerospace engineering.

Over the years, astronauts have smuggled object with them on space flights. Alan Shepard, Apollo 14 commander, smuggled 3 golf balls and a six iron club head modified to attach to a sample scoop handle. The first ball was barely hit and rolled into a small, nearby crater, the first lunar hole in one. The second was a better hit. Shepard claimed it went for “miles and miles” in the reduced lunar gravity, although subsequent analysis of the video by NASA engineers found it actually traveled a mere 40 yards. I’ve had shorter tee shots in my very short golfing career.

Scott Kelly in a gorilla costume onboard the ISS. Credit Scott Kelly

During astronaut Scott Kelly’s year-long mission on the ISS in 2016, his twin brother Mark secretly sent a gorilla suit on a cargo resupply mission. Scott wore it while chasing crewmates through the station. Videos of him cavorting as a gorilla are still available on the internet.

Who knows what strange object some space agency will next send to space?

 

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.

Water Bears Might Help Humans Colonize Mars

 Perhaps you have heard of tardigrades, also known as water bears or moss piglets. They are tiny, 8-legged critters that live in water. They can be found all over our planet. They are known to survive extreme conditions. They can be frozen, boiled, dried out, or stuck on the outside of a spacecraft in the vacuum and high radiation levels of space and still survive. This survivability may prove to be very important to future Martian colonists.

National Geographic describes them like this. “Scientists have discovered roughly 1,300 species of tardigrades worldwide. These creatures are considered aquatic because they need a thin layer of water around their bodies to prevent dehydration. Despite their need for water, they live in all kinds places, from the deep sea and hot springs to terrestrial environments like sand dunes. Terrestrial tardigrades prefer freshwater mosses and lichen habitats, hence their nickname, moss piglet.”

Tardigrade, also known as water bears and moss piglets. Shuttercock

Martian colonists will have to grow their own food. Sending constant supply ships to deliver food and water is impossible. But the soil of Mars is poisonous to plants, primarily due to high levels of salt, particularly perchlorate, in the planet’s soil. In the movie “The Martian” starring Matt Damon, an astronaut who was mistakenly thought to have died, was left on Mars. He managed to grow potatoes and survived until he could contact Earth and have a rescue mission sent to retrieve him.

A recent paper from researchers in the U.S., Poland and the U.K. led by lead author Corien Bowerman’s, a professor of Microbiology at Penn State, shows how tardigrades might help future astronauts survive on Mars. A major part of the diet of Tardigrades consists of the cellular fluids of bacteria and other microscopic cells. They can clean the soil to help crops grow.

Potatoes and many other crops could be grown in Martian soil, except for the salts. The soil on Mars isn’t like what’s in your backyard. The planet is covered in loose, rocky debris and dust, what scientists call regolith. The researchers added tardigrades to some simulated Martian regolith but within two days, the hardy water bears all died. In order to remove any toxic contaminates in the soil, they washed it with water then added more tardigrades. To the researchers delight, they thrived.

Martian colonists drillingh for water. NASA

The researchers concluded that tardigrades could help future colonists on Mars survive. Once the regolith covered by greenhouses was cleaned, the tiny creatures would help Earth crops grow. The researchers cautions that more study is need. “These experiments have ramifications for the choice of species for functional soils to support plants and humans on Mars and for the limitations of terrestrial life; however, more testing is necessary to fully understand the potential habitability and dangers of Martian regolith.”

Martian Colony. NASA

We may have our first Martian colony within a few decades. The tiny water bears will help those brave colonists to survive.

  

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.