Good news doesn't stop happening in the world of astrophysics. It's true that we haven't yet found signs of extraterrestrial life, and it's increasingly plausible that 2030 will give us a surprise. On October 10 this year, NASA's Europa Clipper mission will launch to search for life on Jupiter's icy moon Europa. This satellite is, in fact, an ocean world, its surface frozen, but containing two or three times as much water as Earth, concentrated in a diameter slightly smaller than that of our Moon.
Recently, several articles have suggested that life in Europe is even more possible than we thought, and now, The research confirms that Europa Clipper can detect signs of life in ice sheets predicted from certain gaps in its icy surface. . This means that if there is life on that Jovian moon, it is highly expected that signs of it will appear within 6 years and a few months, since, if all goes as expected, the Europa Clipper mission ship will reach its destination. On April 11, 2030.
Scientists are convinced that beneath the first 25 kilometers of ice lies a 90 kilometer ocean that is almost 20 times deeper than the average depth of Earth's hydrosphere. The water is surrounded by solid rock, with iron and nickel at its heart very similar to our planet. . But if the ice covering it is so thick, how do we know all this?
Europa is the “softest” body in the Solar System. The ice has almost no craters or large mountains, which raised suspicions because its neighboring moons are full of holes. If this happens, it means that its surface is being renewed. In fact, although Europa is 4.5 billion years old, its surface is only 20 to 180 million years old.
On Earth, crustal plates move over the crust, which is more plastic and warmer than the surface. In the case of Europa, it is expected to move like an ice sheet because there is some liquid beneath the ice sheet. It also explains the strange lines that cross its surface. These are areas where the ice sheets have broken up and quickly exposed the re-frozen sea. And, if that wasn't enough, in December 2013, the Hubble Space Telescope detected two jets of pressurized water coming from Europa's southern hemisphere, confirming the theories.
Jupiter is massive, and its gravitational pull is massive, meaning that Europa is warped as if elongated in the direction of the planet. This drag is called “tidal force” because it causes sea levels to rise in one area and fall in others because the water erodes more easily than the land it rests on.
It adds that Europa participates in the Laplace resonance, a phenomenon of interest, and that Europa and the other major Jovian satellites are synchronized. For every revolution Ganymede makes around Jupiter, Europa makes two and Io four. Being in sync, together they are eroding Europa, intensifying the tidal forces and melting its interior like an immense cosmic coolant.
It's not the same, but it can be intuitively understood using a rubber band. Let's cut it and take its ends, one in each hand. Now let's stretch it to the maximum, wait for a second and join the hands again to release the tension. Once this is done, press the rubber between your lips. You'll notice how the decay has heated it up.
Two new studies published at the end of 2023 add to doubts that have historically arisen in Europe. They confirmed the presence of carbon dioxide on the moon's surface, a substance commonly associated with biological processes, and found that this carbon comes in one way or another from the oceans beneath the moon's icy shell. And while it is true that it can have many appearances, not all of them point to the existence of life, but it does point us in the direction of our choice.
In fact, a recent study shows that Enceladus contains phosphate, one of the basic building blocks of life. Now, the study has just been published Scientific advancesWritten by the same researchers as Phosphate, it tested the Europa Clipper mission's ability to detect signs of life in the icy crusts emanating from Europa's surface, and the results were very promising.
The reason is as follows: If life forms in Europa found a solution similar to ours to create barriers separating their bodies from the vast ocean, we might expect them to use something like fatty membranes.Made up of substances that repel water, simple life forms (equivalent to our bacteria) can occur that form a foam on the surface of water, as happens on Earth.
Exposed areas of liquid water, between the ice sheets, are at very low pressure, so even at very low temperatures water can “boil”, boiling bubbles bursting as they reach the surface, revealing froth loaded with extraterrestrial microbes. These chunks of foam, which are mostly water, freeze in space to form ice crystals that, luckily, still contain alien “bacteria” species.
Life in small packages
In a study recently published by the University of Washington, jets of liquid water were fired into a vacuum container, which disintegrated the droplets and simulated space. Contains bacteria called water droplets Sphingopyxis alaskensissmaller than those typically used for these studies Escherichia coliThey are therefore better suited to the ice masses to be studied. The Sphingopyxis It lives in a cold environment with few nutrients, making it a strong candidate to simulate an alien microbe from Europe.
The researchers then manipulated those droplets Sphingopyxis They use a laser to excite their atoms, and when the laser is turned off, they release some of the extra energy they've gained in the form of light. This light contains the signature of each element that makes up the pattern, like a colored barcode. And, to the researchers' delight, the technique, called mass spectrometry, was successful enough to identify life in those droplets.
And if this technique can detect life in these conditions, so can Europa Clipper, since it uses a similar system. It's early days for success, but there's no doubt we're closer than ever to finding some form of life there. Simple life forms, perhaps, but it helps us understand our place in the universe as a relatively ordinary, organized thing that we like to call “life.”
I do not know:
- Even when we talk about alien bacteria, we do so in quotation marks, because they are not expected to be bacteria like us, but life forms identical in some of their key characteristics, their equivalent unit of life, their version of the cell. And, of course, even if they were bacteria, nothing made us think they could be infectious.
Notes (MLA):
- How to detect cellular material in an icy plume ejected from Enceladus or Europa scientific advances, 2024 10.1126/sciadv.adl0849
- Samantha K. Trumbo et al. “Distribution of CO2 in Europe indicates internal source of carbon”. Science, 2023 https://www.science.org/doi/10.1126/science.adg4155
- GL Villanueva et al. “Undetected Endogenous CO2 Ice Composition and Plume Activity at Europa's Surface”. Science, 2023 https://www.science.org/doi/10.1126/science.
- Paganini, L. and many others. “Measurement of water vapor in the middle of a large calm environment on Europa”. Nature Astronomy, 2019. Springer Science and Business Media LLC, doi:10.1038/s41550-019-0933-6. Accessed on 11 March 2020.
- Quick, Lynne C. and many others. “Constraints on the Detection of Cryovolcanic Plumes in Europe”. Planetary and Space Science, Volume 86, 2013, p. 1-9. Elsevier BV, doi:10.1016/j.pss.2013.06.028.
