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.