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preparation efforts, including the most recent guidelines, which were developed in 1989 (pre-World Wide Web), are outdated.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.

Did an Alien Race Signal Us?

 Astronomer Frank Drake first pointed a radio telescope toward the skies in 1960 in a deliberate search for alien signals, and SETI, the search for extraterrestrial intelligence, began. Since then, astronomers have spent many thousands of hours searching for alien signals.

In 1965, Ohio State University built the Big Ear radio telescope specifically to search for alien transmissions. On the night of August 15, 1977, astronomers ran an automated scanning program in a region of the constellation Sagittarius. At 10:16 p.m., the telescope detected a 72-second burst of radio noise in the frequency range astronomers thought the best to search for alien signals. The next morning, astronomer Jerry Ehman reviewed the computer log and noticed a signal that was 20 times stronger than the background noise. He circled that portion of the computer printout and wrote “Wow!” in the margin.

Although astronomers have repeatedly searched that area of the sky looking for a repeat of the Wow signal, it has never come again. Over the years since, astronomers hunted for any possible non-alien explanation for the signal without success. Recently, the director of the Habitable Exoplanet Hunting Project, Alberto Caballero, stated "The 'Wow!' signal is still considered the best SETI candidate radio signal.” He began a search of the region of the sky where the signal originated looking for likely candidate stars.

                                            The "Wow!" signal. Credit SETI Institute

He searched for stars similar to our sun in size, age, and brightness that might host Earth-like planets. He examined data collected by the European Space Agency’s Gaia mission which is creating a map of more than a billion stars with unparalleled precision. He found 66 candidate stars similar to our sun.

Astronomers must now examine those stars to see if any possess Earth-like planets orbiting them. This process may take a while, but if the Wow signal came from an alien race, this may be our best chance to discover another intelligent civilization. At such great distances to these stars, back-and-forth communication may be impossible. But, at least we’d know we’re not alone in the universe.

 

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.

Alien Signals? Likely Not, But the Most Exciting Possibility Yet!

      Earth is a noisy planet. Not with sound waves, which never leave the atmosphere, but with all sorts of radio noise. Between radar beams from weather monitoring stations, airports and military use, TV and radio signals, and even deliberate attempts by astronomers to send messages to any listening aliens, our planet constantly announces its presence to the universe at large.

Because we are so radio noisy, astronomers have for decades tried to find such radio signals emanating from any other existing alien civilizations in our Milky Way, with little success. In 1977, astronomers performing such a search with a giant radio telescope run by Ohio State University detected a signal, a powerful radio burst, dubbed the “WOW!” signal. It never appeared again despite much searching.

In 2015, billionaire Yuri Milner donated $100M to create a program designed to search for extraterrestrial radio signals, the Breakthrough Listen Project. The project uses the Parke Radio Telescope in Australia, operated by the Commonwealth Scientific and Industrial Research Organization.

 Recently, news broke that the project detected a narrowly-focused beam of 980 MHz radio waves detected in April and May 2019. The signal came from the direction of our nearest stellar neighbor, Proxima Centauri, which has two planets orbiting it, and one is Earthlike. That frequency is important because human-made craft and satellites typically don’t use it, lending credence to the possibility of it coming from an alien civilization.

Parke Radio Telescope, credit Commonwealth Scientific and Industrial Research Organization

The powerful burst excited astronomers of the project. Sofia Sheikh, an astronomer at Penn State University, led the analysis of the signal. While the team has yet to release its full report, Scientific American interviewed Sheikh. She said, "It's the most exciting signal that we've found in the Breakthrough Listen project because we haven't had a signal jump through this many of our filters before.”

No repeat signal has been detected, and the team still must rule any natural signals, such as a distant comet or some other astronomical. But astronomers excitedly await the full report. We may have finally discovered that we have neighbors.

 

    Each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

    This is reprinted by permission from the Oklahoman and www.newsok.com.

Are We Close to Finding Earth 2?

 

NASA and other space agencies have launched several missions to search for exoplanets, planets that orbit other stars. The Holy Grail of such programs is finding an Earth-like planet orbiting a sun-like star at the right distance to allow liquid water on the surface. Such planets seem to be the most likely candidates to search for life.

While astronomers have yet to find a perfect Earth 2, statistical analysis of NASA’s most successful planet hunter, the Kepler Mission, uncovered some promising data. A study by NASA scientists alongside collaborators from around the world who worked on the Kepler mission came to an exciting conclusion. According to the research, about half the stars similar in temperature to our Sun could have a rocky planet capable of supporting liquid water on its surface.

Image Caption/Credit: NASA’s Kepler Planet Finder telescope, credit NASA

"Kepler already told us there were billions of planets, but now we know a good chunk of those planets might be rocky and habitable," said the lead author Steve Bryson, a researcher at NASA's Ames Research. "Though this result is far from a final value, and water on a planet's surface is only one of many factors to support life, it's extremely exciting that we calculated these worlds are this common with such high confidence and precision."

Kepler detected planets by continuously staring at thousands of stars, watching for a tell-tale drop in brightness caused by an orbiting planet crossing in front of a star. Such a method couldn’t detect planetary systems seen more face on, so astronomers had to use statistical methods to extrapolate from the Kepler data to all the other stars in our galaxy. Kepler discovered so many exoplanets from its limited mission that astronomers now believe that more than half of the four billion stars in the Milky planet possess planets, typically more than one.

Using their most conservative estimate, that 7% of all sun-like stars have Earth-like planets, meaning some 300 million exist in our Milky Way alone. Their most likely estimate states that Earth-like planets orbit 50% of sun-like stars, making more than 2 billion Earth-like planets. Since we know of only one planet with life, ours, those planets are the best place to begin to search for alien forms of life.

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

 This is reprinted by permission from the Oklahoman and www.newsok.com.

Martian Life, if it Exists, Could Still Be Present Underground

 

Earth sits right in the middle of our sun’s habitable zone, the region where the heat of the star allows liquid water to exist on the surface of a planet. Mars orbits at the outer edge of this zone. Astronomers generally agree that Mars once sported rivers, lakes and, oceans. Mars reached such life-supporting conditions even before Earth. Its smaller size allowed it to cool more quickly from the heat of formation.

But Mars’ smaller size also allowed its core to cool and solidify long ago, killing its magnetic field. Without that magnetic field, solar radiation slowly knocked the atmosphere of Mars into space. Lacking an atmosphere, Mars couldn’t trap the sun’s heat, so it turned cold. Nighttime temperatures routinely drop to near 100 degrees below zero.

But, prior to the loss of its atmosphere, Mars sported conditions that could have supported life. That is no longer true of the surface of Mars. The thin atmosphere can no longer warm the surface of Mars nor protect it from cosmic radiation. Many scientists, including astrophysicist and research scientist Dimitra Atri, from the Center for Space Science at NYU Abu Dhabi, believe that conditions not far below the surface could potentially support life, albeit only at the bacterial level.

In 2022, the European Space Agency and Roscosmos, the Russian space organization, will launch the ExoMars craft, which includes the Rosiland Franklin rover. Atri says that rover will have the ability to detect any such subsurface life on the Red Planet. "It is exciting to contemplate that life could survive in such a harsh environment, as few as two meters (six feet) below the surface of Mars," said Atri. "When the Rosalind Franklin rover onboard the ExoMars mission, equipped with a subsurface drill, is launched in 2022, it will be well-suited to detect extant microbial life."

                           ExoMars Rosalind Franklin rover, Credit European Space Agency (ESA).

If we find life on Mars, it will indicate that life forms easily, given that life developed on both planets in our solar system capable of supporting it. That tells astronomers that perhaps many of the tens of billions of Earth-like planets in our Milky Way galaxy likely did, too.

     Each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

     This is reprinted by permission from the Oklahoman and www.newsok.com.

Can Earth-like Exoplanets Actually Support Life?

As of July 4^th, the NASA Exoplanet Archive (https://exoplanetarchive.ipac.caltech.edu/) lists 4,183 confirmed exoplanets, planets orbiting other stars, with another 2089 candidate planets awaiting confirmation. NASA and other institutions have only studied a tiny percent of all the stars in our Milky Way. Based on the sample so far, astronomers estimate that planets outnumber stars in our galaxy. That means the Milky Way contains several hundred billion planets.

These exoplanets come in a bewildering variety. Some are Jupiter-sized planets so close to their parent star that the heat from the star evaporates them. Some Earth-sized planets get so hot, they rain liquid metal from their clouds. Most confirmed planets are significantly larger than Earth, but that’s because larger planets are easier to discover than smaller planets. Astronomer estimate that Earth-sized planets number in the billions.

   Most Earth-like Exoplanets, credit NASA

Being the size of Earth doesn’t mean such a planet has life on it. Many factors play into planet habitability. Distance to its parent star determines surface temperature. Too hot or too cold and habitability becomes unlikely. The type of parent star plays a crucial role. Stars smaller than our sun often produce large, dangerous stellar flares.

If Earth is a good example of what conditions necessary for a planet to support life, water is an absolute must. On our planet, where there’s water, life exists, even at the bottom of the ocean, with near-freezing temperatures, in boiling hot springs, or three miles underground in cracks in the rock.

Scientist Lynnae Quick along with several other NASA scientists looked at the likelihood of finding other life-bearing planets. This initial study contained a small sample of only 53 Earth-sized planets. They specifically looked to see if the planets could support surface or subsurface oceans, as is the case with several moons in our own solar system. Of those, they calculated that 30 likely possess such bodies of water, more than half of the planets they analyzed. With a few billion Earth-sized planets in our galaxy alone, that means there might be a lot of life-bearing planets out there. "Forthcoming missions will give us a chance to see whether ocean moons in our solar system could support life,” said Quick.

The study didn’t address the presence of intelligent aliens. There isn’t enough data to decide that. But at least we have some idea of the possibilities now.

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

 This is reprinted by permission from the Oklahoman and www.newsok.com.

Origin of Life on Earth: The Phosphate Problem

Biologists currently don’t know where or how life began on Earth, but they do have plenty of theories. They have a pretty good idea of what chemicals are required to create life. Five elements are critical for all life on our planet: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Of course, many other elements come into play, but the basic structures in our cells absolutely demand these five. While all exist in our environment, they need to be highly concentrated relative to the environment in general for life to take hold. So much of the investigation into the genesis of life focuses on how to concentrate these elements.

The first, widely-accepted notion suggested that life began in tidal pools at the ocean’s edge. As tides moved out, pools of water left behind concentrated chemicals when the water evaporated. This idea held sway for many years. In the late 1970s, scientists discovered hydrothermal vents on the floor of the Pacific Ocean. These are locations where seawater seeped into Earth’s interior, became super-heated, and came back out through volcano-like vents. The hot water leached minerals out of the rock as it returned to the ocean.

This seemed to many to be even more plausible. But one puzzle still remained. Neither scenario seemed to provide the needed concentration of phosphorus. As Jonathan Toner, a University of Washington research assistant professor of Earth and space sciences described it, "For 50 years, what's called 'the phosphate problem,' has plagued studies on the origin of life.” He led a research team that studied alkaline lakes for a possible solution to the ‘phosphate problem.’ These form in low-lying areas where water collects via drainage from dry environments, often in volcanic regions, like Mono Lake in California.

Mono Lake, California. Credit U. S. Geological Survey

Typically, carbonate combines with and traps phosphorus, but in these alkaline environments, carbonate also combines with calcium which would otherwise lock-up phosphorus, too. The net result is a phosphorus concentration high enough to support life on Earth. Once again, origin-of-life theories have come back to the idea of bodies of surface water as the starting point for life on our planet.

Each month, I write an astronomy-related column piece for The Oklahoman newspaper. On the following day, I post that same column to my blog page.

This is reprinted by permission from The Oklahoman and www.newsok.com.

Human-Tardigrade Hybrids May Be the First Earthlings to Visit Mars

Tardigrades, also known as water bears for their cute appearance, are amazingly hearty microscopic creatures. They can survive being frozen, thrown in boiling water, and other extreme conditions that destroy almost all other Earthly lifeforms. In an experiment by the European Space Agency, a batch of tardigrades sat outside of a satellite in the freezing cold vacuum of space for ten days while intense UV and cosmic radiation bombarded them constantly. Most survived.

Earlier this year, an Israeli lunar lander carried thousands of tardigrades on board as a test to see if they are capable of surviving the harsh conditions of the lunar surface. The craft crashed, but these little guys are so tough, scientists believe that many likely survived that crash.

Tardigrade, also known as a water bear. Credit Shuttercock

Intense radiation remains a major hazard when traveling in space beyond Earth orbit. To go to Mars, for example, astronauts need lots of shielding from cosmic rays, which means lots of weight. And that means a huge launch cost. Astronauts less affected by space radiation can survive with less shielding. And since Mars does not possess an ozone layer to protect against UV radiation or a strong magnetic field to protect against cosmic radiation, life becomes very dangerous for astronauts or colonists there.

NASA plans on sending astronauts to Mars within 15 years. Private companies plan on sending colonists there sooner, perhaps by 2025. We have the technology to get humans to Mars within the next 5-10 years. We may well make the discovery of all time by finding native life there. But can we keep our human Martians safe?

Water bears may hold the answer. Or at least their genes. Scientists studying tardigrades have discovered many of their genetic secrets of survival, and now some have suggested that incorporating tardigrade genes into humans may make it possible for us to survive more easily on Mars or even alien planets.

Would you be willing to become a human-tardigrade hybrid to be the first human on Mars?

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

This is reprinted by permission from the Oklahoman and www.newsok.com

Did NASA Already Find Martian Life?

In 1992, astronomers discovered three objects roughly the size of Earth orbiting another star, the first known exoplanets. No one expected life on those objects because the star was a pulsar, the remains of a star that blew up as a supernova, and the “planets” had actually formed from the debris of that explosion.

Three years later, astronomers found the first true exoplanets orbiting the sun-like star 51 Pegasi. Now, the NASA Exoplanet Archive lists 4113 confirmed exoplanets with more than 3600 exoplanet candidates awaiting confirmation. Astronomers believe that we have only touched the tip of the exoplanet iceberg. Data suggests that our Milky Way galaxy alone contains some two hundred billion planets. As of now, there’s no solid evidence suggesting that life exists on any of them.

But some scientists believe that we already found life on another planet, one much closer to home. In 1976, NASA landed twin spacecraft on Mars, Viking 1 and 2. Each included automated laboratories designed to search for microscopic life on the Red Planet.

Both craft, which landed 4000 miles apart, included a simple test called the Labeled Release experiment. It added a nutrient broth to a small amount of Martian soil and checked to see if any metabolic byproducts, like carbon dioxide, were released. Every test by both landers reported positive results. However, the other experiments on both landers found no organic chemicals, which seemed to preclude any lifeforms. Since then, most scientists decided that some odd chemistry in the Martian soil falsely mimicked those life signs.

Viking Lander, credit NASA

But not all scientists. Gilbert Levin was the principal investigator for the Labeled Release experiment for both landers. In a recent article in Scientific American, he wrote “The Viking LR (experiment) sought to detect and monitor ongoing metabolism, a very simple and fail-proof indicator of living microorganisms. Several thousand runs were made, both before and after Viking, with terrestrial soils and microbial cultures, both in the laboratory and in extreme natural environments. No false positive or false negative result was ever obtained. This strongly supports the reliability of the LR Mars data.”

It may be decades or centuries before we confirm life on an exoplanet, if we ever do. But we may have already discovered life on another planet, right next door.

There are Lots of Earth-like Planets -- How Many are Lifebearing?

Scientists who think about the possibility of extraterrestrial life need data to estimate those possibilities. Because Earth is the one and only known example of a life-bearing planet, it seems logical, therefore, to use ours as a model for life-bearing planets. The first, best place to hunt for alien life would be on planets like Earth

And this is where data is needed. Just how many Earth-like planets exist in our Milky Way galaxy? Fortunately, we have reams of data on planets orbiting other stars from the Kepler space telescope. It spent more than nine and a half years doing nothing but searching for extrasolar planets. It discovered more than 2,600 planets with nearly 3,000 still awaiting confirmation. That’s a lot of data.

One thing astronomers learned from a statistical analysis of that data is that Earth-like planets are rather common. Twenty billion sun-like stars call the Milky Way home, and Kepler teaches us that one in four of them have planets roughly the size of Earth orbiting in the habitable zone, where, as on Earth, liquid water can exist. That’s five billion Earth-like planets in the Milky Way. And that’s not even counting the billions of other stars of different sizes than our sun that also possess Earth-sized planets in their habitable zones.

Artist depiction of a habitable exoplanet. Credit NASA-JPL

That sure sounds like the potential exists for a galaxy teeming with life.

Now, astronomers want to check for the actual existence of alien life. We can’t yet send probes to examine those planets. But we can examine the atmosphere of an alien planet for life-supporting gases. According to Eric B. Ford, professor of astronomy and astrophysics at Penn State, “Scientists are particularly interested in searching for biomarkers – molecules indicative of life – in the atmospheres of roughly Earth-size planets that orbit in the ‘habitable zone’ of sun-like stars.”

With five billion planets to examine, the search might be tedious, but the payoff will be the most amazing scientific discovery ever. And it appears to be only a matter of time before we discover alien life.

The map shows the sky at 10:00 early in the month, 9:00 in the middle of the month, and 8:00 at the end of the month. Map produced using Night Vision star mapping software. 

On or about the first Tuesday of each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

Where is Everybody?

One summer day in 1950, physicists Enrico Fermi, leader of the team that built the first nuclear reactor, enjoyed lunch with several fellow physicists. Talk turned to recent UFO reports and the possibility of faster than light travel. Referring to aliens, Fermi suddenly blurted out "Don't you ever wonder where everybody is?" This question led to “The Fermi Paradox.”

Simply stated, if (as we now know) our galaxy contains billions of planets, many of them Earth-like, why haven’t we ever encountered any aliens? Earth is young, in cosmic terms. Many solar systems older than Earth exist, some billions of years older. If life existed on any of them, it would take no more than 50 million years to colonize the galaxy with the rocket technology being developed at that time, a blink of the eye in cosmic terms. So, Fermi wondered aloud, where is everybody?

Over the years, other scientists have suggested various answers.

Water is essential to life as we know it. Earth’s water exists on the surface, but for most of the other worlds in our solar system that possess oceans, four moons, the water is locked underground, below a frozen surface. That may be common for life-bearing planets or moons.

Many of the planets we’ve discovered that could have water are classified as super-Earths, planets up to ten times larger than Earth. The gravity of such planets may well make space travel impossible.

Futurist and astronomer Seth Shostak, says that all intelligent aliens may actually be intelligent machines. We ourselves are on the verge of creating such machines and, within a few thousands of years, all intelligence on Earth may be machine-based, not biological.

Some scientists suggest that alien life may be so different from us, we’d never recognize it. Or, perhaps just as we destroy ants without even realizing it when building a house, maybe all other life forms have been eradicated. Or they wiped themselves out with climate change.

Maybe we have met the aliens and they are us. The “panspermia hypothesis” says life was seeded on Earth by comets (or alien spacecraft?), making us the very aliens we search for.

Even so, we need to keep looking.

From NASA's search for extraterrestrial life. Credit NASA-HST

On or about the first Tuesday of each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

This is reprinted by permission from the Oklahoman and www.newsok.com.

Water on Mars from Deep Groundwater Sources

In 2015, NASA announced the discovery of water flowing down the sides of craters on Mars. NASA calls them Reoccurring Slope Lineae, RSL for short. This seemed to answer the question of whether liquid water currently existed on Mars. And since liquid water is believed to be a prime requirement for life, the discovery also reinvigorated the discussion of life, even if only microscopic, on the red planet. You can see a NASA video montage of some RSLs at https://youtu.be/H44-XrGH5IQ.

Reoccurring Slope Lineae on Mars, credit NASA

In 2017, some researchers published papers suggesting RSLs were not from water but consisted of sand sliding down the slopes, driven by carbon dioxide that sublimated from dry ice just below the surface. Carbon dioxide, being a relatively heavy gas, flows downhill and carries sand grains with it. The researchers suggested that the sand just below the surface might be darker, having not been bleached by UV radiation from the sun.

The consensus of scientific opinion, however, rested with water flow, but many wondered if water just below the surface of the cold planet could never melt. Recently, Essam Heggy, a research scientist at the University of Southern California and NASA's Jet Propulsion Laboratory, and Abotalib Z. Abotalib, a postdoctoral research associate at USC, suggested that the flows are triggered not by near-surface water but rather from deep below the surface. "We propose an alternative hypothesis, that they originate from a deep, pressurized groundwater source, which comes to the surface, moving upward along ground cracks," said Hegggy.

They compared Martian geological features to similar ones on Earth and determined that heat flow in the Martian subsurface was similar to that in desert regions here on Earth. This research, the two concluded, indicates that RSL water is probably coming from deeply buried, briny aquifers.

This even explains the seasonal aspect of the flows. "The system shuts down during winter seasons, when the ascending near-surface water freezes within fault pathways, and resumes during summer seasons when brine temperatures rise above the freezing point," the researchers wrote.

The new study says nothing about the existence of life on Mars, but it will surely strengthen arguments for at least microbial Martians living below the surface.

       On the first Tuesday of each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

      This is reprinted by permission form the Oklahoman and www.newsok.com.