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. 

How Might the Discovery of Extraterrestrial Life Affect Religions?

 Many of my columns focused on the likelihood of extraterrestrial life. Not necessarily intelligent aliens, but more likely microbial life. I’ve covered such topics as the discovery of planets around other stars, the chemistry necessary to support life, and where we have found it. I’ve talked about Earth creatures that can survive long stretches of time in space, like the hardy tardigrades.

The detection of life elsewhere, intelligent or not, would go down as one of the most profound discoveries in human history. I’ve always discussed this in scientific terms. That’s my background and the point of these columns.

Recently, NASA co-sponsored a study at Princeton University's Center for Theological Inquiry with two dozen theologians from many religions who discussed how humans might respond to the discovery of extraterrestrial life.

For centuries, the Catholic Church said that extraterrestrial life, at least intelligent life, couldn’t exist because the Son of God only came to Earth to save God’s creatures. In their minds, that meant only Earth possessed life. In the eyes of the early Church, no planets existed beyond our solar system

Those individuals who disputed the Church’s stance, like Giordano Bruno, faced strong retaliation. Among other “heretical” statements, Bruno said, “In space, there are countless constellations, suns and planets; we see only the suns because they give light; the planets remain invisible, for they are small and dark. There are also numberless earths circling around their suns...” For this, among other heresies, Bruno was condemned to death in 1600.

We now know of many thousands of planets beyond our solar system, and astronomers believe that number likely exceeds one hundred billion. So how might religions react to the discovery of life out there? Study participant Rev. Dr. Andrew Davison of the University of Cambridge stated wrote in his forthcoming book on the study “Astrobiology and Christian Doctrine,” “The headline findings are that adherents of a range of religious traditions report that they can take the idea in their stride."

NASA takes a new look at Extraterrestrial life 

Credit NASA

Davison also states the nonreligious community tended to "overestimate the challenges that religious people" might face if extraterrestrial life were discovered. A "large number of people would turn to their religious traditions for guidance."

How might you react to such a discovery? At least according to this study, religious folks might have an easier philosophical time digesting it.

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The element carbon is ubiquitous on Earth. And, it is the basis of all life on our planet. Carbon, like many elements, comes in multiple forms called isotopes. Carbon has two stable isotopes, carbon-12 and carbon-13. Carbon-12 is by far the more common isotope, but all life on Earth prefers carbon-12, and the ratio of carbon-12 to carbon-13 is higher in biological molecules than in non-biological molecules.

Recently, the Curiosity Rover drilled a hole into the Martian surface and found an enrichment of carbon-12 over carbon-13. Does this mean there’s life on Mars? Not necessarily, but if a scientist found such a discovery in any dirt on Earth, she would certainly assume so.

  

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.Oklahoman.com.