Search for Extraterrestrial Life Heating up

Two recent studies have excited scientists interested in looking for extraterrestrial life. Both hint at possible life on other celestial bodies.

The one closest to home comes from the ongoing Juno spacecraft mission studying Jupiter and its moons. Astronomers have long known that one of Jupiter’s moons, Europa, is covered with a thick layer of water ice, and below that icy shell lies an ocean up to 100 miles deep that holds more water than all of Earth’s oceans. The combined gravity of giant Jupiter and Ganymede, the largest moon in our solar system, pull and squeeze Europa, providing the energy to keep that ocean liquid.

That same gravitational tug-of-war may create volcanic vents on the floor of Europa’s ocean. The vents constantly pump minerals into the water, the same circumstance that many scientists believe led to life on Earth.

The latest data from Juno indicates that Europa generates 1000 tons of oxygen every 24 hours. That’s enough oxygen to support one million humans. On Earth, free oxygen is produced by living plants. The bulk of our oxygen comes from tiny algae plants in the ocean using photosynthesis to create food and release oxygen as a byproduct.

The researchers believe that charged particles driven by Jupiter’s strong magnetic field impact the icy shell on Europa and break apart the water molecules to create free oxygen. While the oxygen isn’t produced by life processes, researchers believe that this oxygen can make its way through the icy shell to the ocean below. This oxygen may then accelerate the evolution of any life in the ocean to create more complex creatures, just as happened in Earth’s oceans.

Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio, Texas, said, “Our ability to fly close to the Galilean satellites during our extended mission allowed us to start tackling a breadth of science, including some unique opportunities to contribute to the investigation of Europa’s habitability.”

Jupiter's moon Europa, credit NASA

The other study comes from the Webb space telescope. In 2015, NASA’s K2 mission discovered a planet dubbed K2-18b orbiting a cool, red dwarf star. K2-18b sits in the star’s habitable zone where liquid water can exist on the surface. The research study led by Nikku Madhusudhan, a professor at the University of Cambridge, identified methane and carbon dioxide in the planet's atmosphere, a strong indication that the planet could be covered in an ocean.

K2-18b is a sub-Neptune planet, one between the size of Earth and Neptune, but, since no such planet exists in our solar system, we don’t understand their properties very well. "Although this kind of planet does not exist in our solar system, sub-Neptunes are the most common type of planet known so far in the galaxy," said Subhajit Sarkar of Cardiff University, co-author of the study. "We have obtained the most detailed spectrum of a habitable-zone sub-Neptune to date, and this allowed us to work out the molecules that exist in its atmosphere," Sarkar added.

Artist concept of K2-18b, credit ESA, NASA

That spectrum indicated the presence of dimethyl sulfide which only living organisms can produce, at least here on Earth. Is this ocean world teeming with life? It's far too early to know if life exists there says Madhusudhan, and the researchers were quick to point out that more data is urgently needed. ''If confirmed,” he said, “it would be a huge deal and I feel a responsibility to get this right if we are making such a big claim."

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. 

Can't Afford Musk's Rocket Flight? Try Space Perspective!

 A few dozen very wealthy people have flown to space on ships operated by private spaceflight companies. Two companies, Virgin Galactic and Blue Origin take paying customers above the Karmen Line, 62 miles high, which defines the start of space. Passengers experience brief moments of weightlessness and enjoy an equally brief view of space and our spherical planet below them before plunging back down to Earth. Neither of these two companies takes passengers on orbital flights around Earth. The entire flight takes a matter of minutes, and these passengers pay as much as $25M for the experience. The private passengers must undergo a few days of training for the experience.

While all those spaceflight passengers claim the experience to be well worth the price, that’s not something ordinary people like you and I can afford. But a much cheaper option is about to become available. A company called Space Perspective expects to launch the maiden passenger voyage of its Spaceship Neptune later this year. It’s not a typical rocket. A balloon will carry a lavish, spherical passenger cabin 20 miles high. It won’t technically reach space, but the company claims the view is very similar to the suborbital flights. Passengers will experience the blackness of space and see the curvature of our planet below, but will not experience weightlessness.

Artist's illustration of Spaceship Neptune high in the atmosphere. Credit: Space Perspective

The first Spaceship Neptune capsule, named Excelsior, will have plenty of room to move around in. A company post on social media says “Spaceship Neptune will have the largest windows ever flown to space and a spherical design that allows for the roomiest interior of any human spaceflight capsule ever made" The 16-foot diameter cabin has rows of padded seats facing the multiple giant windows, 5 feet high by nearly 2 feet wide. The capsule even includes a bar station and a bathroom.

The capsule ascends at a leisurely 12 miles per hour, taking two hours to reach the final altitude. This gentle liftoff means passengers don’t feel the multiple g-forces from a traditional rocket launch. Passengers then spend two floating near the edge of space followed by a two-hour descent and a gentle splash down in the ocean. A waiting ship gently lifts the capsule onto its deck, and passengers are out within 15 minutes of landing.

Spaceship Neptune's interior with a view of Earth through the windows. Credit: Space Perspective

Spaceship Neptune creators have strong qualifications. The company’s CEOs, Taber MacCallum and Jane Poynter, also co-founded Paragon Space Development Corp. Life support and thermal control systems from Paragon have been included in the designs of every human-rated spacecraft the United States has ever flown.

While Spaceship Neptune won’t reach true outer space, it surpasses a key boundary called the Armstrong line. This is the height at which air pressure is so low that water will boil at normal body temperature.

The $125,000 ticket price is still rather steep for the ordinary person, but far more affordable than the millions of dollars for a suborbital flight. And the two-hour duration at altitude allows for a memorable time, even if you can’t brag about going to space.

NASA Innovative Advanced Concepts Awards

 Every year, NASA offers preliminary funding to several unusual projects. The NASA Innovative Advanced Concepts (NIAC) program “nurtures visionary ideas that could transform future NASA missions with the creation of breakthroughs – radically better or entirely new aerospace concepts.” Some of the past NIAC award-winning ideas that became a reality include the Ingenuity helicopter now flying on Mars and Cubesats, small one-foot cube satellites that can use smartphones as the onboard computers. You’ve always heard how powerful of a computer your iPhone is! Other funded NIAC proposals include such diverse projects as the 3-D printing of biomaterials such as arrays of cells and a proposal to use the sun as a gravitational lens to study exoplanet surfaces. One idea proposes using bacteria and fungi brought from Earth plus known gases and soil materials on Mars to create bioengineered building materials. This dramatically reduces the weight needed to be sent to Mars to create safe habitats for future Martian astronauts.

NASA awarded 13 new NIAC awards in 2023 for projects beginning this year. The two most exciting for me are a Venus Sample Return mission and sending a cluster of microsatellites to study the nearest exoplanet.

Over four decades ago, the Soviet Union landed multiple Venera probes on Venus. But conditions on Venus quickly overwhelmed them. Surface temperatures reach nearly 900 degrees, hot enough to melt lead. Atmospheric pressure is ninety times that on Earth. Although each of the 10 landers provided valuable information about the planet, the longest-lasting probe, Venera 12, only lasted 110 minutes.

One NIAC award went to a team that wants to use the high-temperature technology developed for probes that study the sun up close plus an innovative rocket engine design that can use fuel created from the gasses in the Venusian atmosphere to return samples from the surface of the planet. Venus may once have been much like Earth, but the runaway greenhouse conditions turned it into a hellish environment. This mission might allow us to better understand the conditions on Venus before that change.

The surface of Venus from Venera 13. Credit Russian Science Academy

The closest star to us, Proxima Centauri, is 4.2 light years, 25 trillion miles, distant. Using our current fastest rocket technology, it would take us more than 50,000 years to reach it. A roughly Earth-sized planet, Proxima Centauri B, orbits the star. One NIAC award went to a group to study the feasibility of sending thousands of tiny spacecraft to study that planet. They plan to power them using a 100-gigawatt laser beamed at the swarm from Earth. The tiny crafts would work together creating the equivalent of a giant dish antenna to send signals back to Earth. They estimate the trip would take only 20 years and data returned at the speed of light requires only 4.2 years.

The nano-spacecraft would take 20 years to reach Alpha Centauri. Credit Breakthrough Starshot

Only a handful of NIAC awards lead to actual NASA missions. I hope these two come to full fruition.

 

Watch a Dragon Eat the Sun!

NOTE: Although this column is written for Oklahomans, the links in the article give information about where else in the United States you can see this total solar eclipse.

Imagine life as a human 10,000 years ago. If you are male, much of your time is spent hunting game by yourself or with other men in your group. Some animals were easy to catch, like rabbits or even deer. But hunting bigger animals, like mastodons, could prove dangerous, even deadly. If you’re female, much of your time is spent gathering nuts, berries, or other edible plants and taking care of infants. One of your most dangerous jobs is childbirth. 

At times, your survival might be severely threatened. Bad weather, wildfires, and animal stampedes, all can make life miserable.

Now, imagine a bountiful summer. Food is plentiful, your cave or hut protects you from wild animals and bad storms. But as you finish your afternoon meal, you notice something odd. The light seems different, muted, like a hazy sky. But, the sky is perfectly clear. Moment by moment, the sun’s light slowly fades. Animals start acting oddly, too. Birds began to roost in the middle of the day. Herd animals form circle groups as they do when they protect their young at night. 

You squint at the sun and gasp. Half of it is missing! The light dims more as the sun disappears. Just as it vanishes, yellow petals seem to sprout from a central dark mass. Your tribe fears a demon or dragon is eating the sun. You start screaming, banging rocks and sticks together, anything to make as much noise as possible, hoping to scare away the beast.

Dragon eating the sun, creating an eclipse.

Your efforts pay off as the beast slowly regurgitates the sun.

That’s how our distant ancestors likely reacted to a total solar eclipse. But we know better today. No dragon eats the sun. Rather, the Moon occasionally slides in front of it, blocking its light for a few minutes.

You have a chance in Oklahoma to witness this scary dragon devour our sun, and you should start planning now.

Total solar eclipse revealing the sun's corona.

A total solar eclipse occurs in Oklahoma on April 8, 2024, beginning at 1:44 pm CDT with the final exit of the Moon’s shadow from the state at 1:51 pm CDT. As it passes through Oklahoma, the Moon’s shadow will accelerate from 1680 miles to 1745 miles per hour. The path of totality cuts through the far southeast corner of Oklahoma after passing through the Dallas-Fort Worth Metroplex and heading northeast. Prime viewing sites may get crowded, so start planning your eclipse expedition. Visit tinyurl.com/3du4z57e for more specifics about the eclipse including a detailed map of the path in Oklahoma. More information, including weather prospects, can be found at eclipsophile.com/2024tse/.

And, if you miss this eclipse, you have a while to wait for the next one. We won’t get another total solar eclipse visible from the central United States until August 12^th, 2045.

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.

Massive Solar Storms Potentially Deadly to Life on Earth

 On September 1, 1859, a solar storm of unprecedented power struck Earth. The large burst of electromagnetic energy sent huge voltage surging through telegraph wires, the only means of long-distance communication at that time. It caused sparking and in some cases melting of the wires. Telegraph equipment throughout Europe and North America became useless; some stations even caught fire. Known as the Carrington event, this is still the most powerful solar storm that ever hit our planet in recorded history.

Coronal Mass Ejection event. Credit NASA and Goddard Spaceflight center

On March 13, 1989, a smaller but still significant solar storm struck. It overwhelmed electrical power stations in eastern Canada, leaving 6 million people without electricity. It even melted power transformers in New Jersey. This event carried a fraction of the energy of the Carrington event, but it showed how vulnerable modern technology is to such solar storms. 

If a solar storm like that responsible for the Carrington event hit us today, damage to Earth’s electrical generation and distribution systems could take weeks or longer to fix. The loss of satellites would disrupt communications and financial systems. Even internet connections would be lost until all the damage could be repaired. Replacing damaged satellites of all kinds would take many years.

A more massive solar storm struck Earth 14,300 years ago. Scientists discovered it by studying tree rings which showed a huge spike in a single year. They discovered a huge spike in radioactive carbon in a single year in tree rings. This radiocarbon data corresponds to an increase in beryllium, a marker of solar activity, found in glacier ice in Greenland from the same timeframe. The energy of this storm dwarfed that of the Carrington event.

Solar storm. Credit NASA

"Extreme solar storms could have huge impacts on Earth,” said Tim Heaton, co-author of the tree-ring study. “Such super storms could permanently damage the transformers in our electricity grids, resulting in huge and widespread blackouts lasting months."

NASA uses multiple spacecraft that constantly monitor the sun looking for solar storms. They analyze these events and, in the case of a civilization-ending solar storm, NASA scientists believe that they could give the planet about 30 minutes' notice before a potentially devastating solar storm hits.

Thirty minutes warning to the end of technology, however briefly, that everything in our lives depends on. Such an event would bring civilization to its knees.

 

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

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

 

Our Closest Black Holes

 The Cosmic Zoo contains some really strange beasts. Stars that are fifty times larger than our sun with surface temperatures above 100,000 degrees, compared to our sun’s temperature of a measly 10,000 degrees. Tiny stars with less than a tenth the mass of our sun and surface temperatures cooler than lava. Supernovae that can outshine an entire galaxy. Neutron stars, large stars that collapsed down to the size of a small city, so dense that a teaspoonful can weigh millions of tons.

Perhaps the weirdest celestial inhabitants are black holes. These form from the remains of giant stars at least 25 times the mass of our sun. They warp space and time in their vicinity. They can devour entire stars and shoot our death rays of energy that can easily destroy a planet with a direct hit.

Fortunately, there are no black holes close to us. At least that we know of. But you can easily spot the resting place of the closest black holes to us.

Stars are born in star clusters, typically a hundred or more at a time. We can identify a few dozen stars born with our sun four and a half billion years ago. All star clusters form lots of small stars, a moderate number of average stars around the size of our sun, and only a few very large stars. Large stars burn out quickly and, if large enough, form black holes.

Photograph of Hyades star cluster in Taurus with the bright star Aldebaran in the lower left. Credit Maurice Toet

The closest star cluster to us is the Hyades star cluster. It sits in the constellation of Taurus, the Bull. It makes the face of the bull with the bright star Aldebaran marking one of the bull’s eyes. The Hyades cluster is only 150 light years away, practically in our backyard as stellar distances go.

The constellations around the Hyades star cluster. It is visible near the eastern horizon at 11:00 p.m. in October, but high in the sky in early February evenings. Map produced using Night Vision star mapping software.

A research team led by Stefano Torniamenti from the University of Padua in Italy studied the distribution and dynamics of stars in the Hyades star cluster. “Our simulations can only simultaneously match the mass and size of the Hyades if some black holes are present at the center of the cluster today,” Torniamenti said.

That’s not surprising. Astronomer Simon Zwart of the University of Cambridge studies the dynamics of star clusters. Though not involved in the new study, he says “Every open cluster older than some 5 million years and containing over 1,000 stars is expected to host a few black holes.”

Taurus is highest in the sky in late winter and early spring but is visible around 11:30 p.m. in the eastern sky. The black holes themselves are invisible, but you can easily spy their home star cluster. 

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.

Surf's Up! In a BIG Way!

 As stars go, our sun is rather average in size. The smallest stars, called red dwarf stars, can be less than one-tenth the mass of our sun. The largest stars are fifty times our sun’s mass or more. Most stars are not single, like our sun. NASA estimates that more than half of all stars have one or more partners, where two or more stars are in orbit around each other. Some astronomers calculate that as many as 85% of stars in the universe are in multiple star systems.

Sometimes stars in a double star system can orbit quite close to each other. That can cause some strange effects.

When you hear the words tides and waves, you probably picture an ocean beach, perhaps with surfers. On Earth, our tides are caused by the gravitational pull of the Moon. But our tides are rather gentle, with the ocean’s edge slowly creeping up and down the beach twice a day.

If two stars orbiting each other come close together, each can pull tides on its companion. If those stars are really large, they can pull big tides. 

Stars orbiting close together can pull large tides on each other. Credit NASA, JPL

Astronomers describe a binary system in which the two stars have elongated orbits as “heartbeat stars.” Because of their orbits, the distance between the stars can vary dramatically. When the two stars are closest, they can cause huge tidal forces on each other, which causes large, regular brightness changes in the stars, such as a heartbeat might do on an electrocardiogram.

A heartbeat star (center of each image). Credit: NASA ESA CSA I. Labbé Swinburne University Of Technology Image Processing

One such binary star was first detected in the 1990s during a project known as MACHO which stands for Massive Compact Halo Objects. The ‘smaller’ star is ten times as massive as our sun, while the larger one is 35 times as massive as our sun and 24 times wider than our sun. The tidal force between them doesn’t just create gently moving tides as on Earth. The smaller star pulls tides on the larger star so hard it creates waves 3 times taller than the diameter of our sun.

"Each crash of the star's towering tidal waves releases enough energy to disintegrate our entire planet several hundred times over," says astrophysicist Morgan MacLeod, from the Harvard-Smithsonian Center for Astrophysics who studied the binary pair. "These are really big waves." The smaller star also makes tidal waves, but, being smaller, the waves on its surface are much smaller.

The energy of these gargantuan tides causes the two stars to slowly spiral closer together. Eventually, they will crash into each other and merge into one even larger star. The star system sits in the Large Magellanic Cloud, a satellite galaxy of your Milky Way 160,000 light years away. Too bad, as that collision would be a dramatic sight if it were closer.

Surfers may be desirous of such waves, but they would need to use a lot of sunscreen. The surface temperature of such stars can easily exceed 37 million degrees.

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.