Much of the water on Earth and elsewhere in the solar system likely predates the birth of the sun, a new study reports.
The finding suggests that water is commonly incorporated into newly forming planets throughout the Milky Way galaxy and beyond, researchers said — good news for anyone hoping that Earth isn’t the only world to host life.
“The implications of our study are that interstellar water-ice remarkably survived the incredibly violent process of stellar birth to then be incorporated into planetary bodies,” study lead author Ilse Cleeves, an astronomy Ph.D. student at the University of Michigan, told Space.com via email. [Theories on the Origin of Life]
“If our sun’s formation was typical, interstellar ices, including water, likely survive and are a common ingredient during the formation of all extrasolar systems,” Cleeves added. “This is particularly exciting given the number of confirmed extrasolar planetary systems to date — that they, too, had access to abundant, life-fostering water during their formation.”
Astronomers have discovered nearly 2,000 exoplanets so far, and many billions likely lurk undetected in the depths of space. On average, every Milky Way star is thought to host at least one planet.
Water, water everywhere
Our solar system abounds with water. Oceans of it slosh about not only on Earth’s surface but also beneath the icy shells of Jupiter’s moon Europa and the Saturn satellite Enceladus. And water ice is found on Earth’s moon, on comets, at the Martian poles and even inside shadowed craters on Mercury, the planet closest to the sun.
Cleeves and her colleagues wanted to know where all this water came from.
The ancestor of all life on Earth might have been a gigantic planetary super-organism:
All life on Earth is related, which means we all must share a single common evolutionary ancestor. And now it appears that this ancestor might have been a single, planet-spanning organism that lived in a time that predates the development of survival of the fittest. That’s the idea put forward by researchers at the University of Illinois, who believe the last universal common ancestor, or LUCA, was actually a single organism that lived about three billion years ago. This organism was unlike anything we’ve ever seen, and was basically an amorphous conglomeration of cells. Instead of competing for resources and developing into separate lifeforms, cells spent hundreds of millions of years freely exchanging genetic material with each other, which allowed species to obtain the tools to survive without ever having to compete for anything. That’s maybe not an organism as we would comprehend it today, but that’s the closest term we have for this cooperative arrangement. All that we know about LUCA is based on conjecture, and the most promising recent research has been in figuring out what proteins and other structures are shared across all three domains of life: the unicellular bacteria and archaea and the multi-celled eukaryotes, which are where all plants and animals evolved from. This isn’t a foolproof method — it’s possible that two extremely similar but not identical structures could evolve independently after LUCA split into the three domains — but it’s a good starting point. Illinois researcher Gustavo Caetano-Anollés says about five to eleven percent of modern proteins could be traced back to LUCA. Based on the function of these particular proteins, it appears LUCA had the enzymes needed to break down nutrients and get energy from them, and it could also make proteins, but it probably didn’t have the tools necessary to make DNA. This fits with other research that suggests LUCA fed upon many different food sources, and that it had internal structures in its cells known as organelles. The big difference between LUCA and everything that came after, of course, is DNA. Because LUCA didn’t have the tools to deal with DNA, it probably used RNA instead, and it likely had very little control over the proteins that it made. The research suggests the ability to precisely control protein manufacture only came long after LUCA split apart, which means that protein-making was probably always a big crapshoot. That’s why LUCA had to be cooperative, with any cells that produced useful proteins able to pass them on throughout the world without competition. This was a weird variation on what we know as natural selections — helpful proteins could go from a single cell to global distribution, while harmful or useless proteins were quickly weeded out and discarded. The result was the equivalent of a planet-spanning organism. So why did this paradise of cellular cooperation give way to the last three billion years of cutthroat competition? The simple answer is that some cells probably outgrew this arrangement, as they had finally developed all the structures needed to survive without help. We don’t know quite why that happened, but it appears to coincide with the sharp increase of oxygen in the atmosphere. Whatever the cause, cells began eking out their own independent existences, ending the reign of LUCA that had lasted hundreds of millions of years… while beginning a new order that is still going strong 2.9 billion years later.
Scientist Finds Hidden Portals in Earth’s Magnetic Field:
According to NASA, Jack Scudder—a researcher at the University of Iowa—has found “hidden portals on Earth’s magnetic field [that] open and close dozens of times each day.” Some of them are open for long periods of time. Scudder says that these portals “create an uninterrupted path leading from our own planet to the sun’s atmosphere 93 million miles away.” Called X-points or electron diffusion regions, they are located “a few tens of thousands of kilometers from Earth. The portals are created through a process of magnetic reconnection in which lines of magnetic force from both celestial bodies mingle and criss-cross through space. The criss-crossing creates these x-points. The portals are “invisible, unstable and elusive,” opening and closing without any warning. When they open, however, they are capable of transporting energetic particles at high speed from the Sun’s atmosphere’s to Earth’s, causing geomagnetic storms. There’s a way to locate them and Scudder has found it. He uses data by NASA’s THEMIS spacecraft and the ESA’s Cluster probes, following crucial clues found in the data from NASA’s Polar spacecraft, which studied Earth’s magnetosphere in the late 1990s:
Using Polar data, we have found five simple combinations of magnetic field and energetic particle measurements that tell us when we’ve come across an X-point or an electron diffusion region. A single spacecraft, properly instrumented, can make these measurements.
NASA is getting ready such a spacecraft in their Magnetospheric Multiscale Mission. A whole squadron of them: four ships that will be deployed around Earth and “surround the portals to observe how they work.” The spacecraft will launch in 2014. [NASA]