An image of the surface of Europa. The top half of the sphere is illuminated with the bottom half dark. The surface is traced with lineae, long lines across its surface of various hues of grey, white, and brown. The surface is a brown-grey, somewhat like Earth's Moon with the highest brightness areas appearing white.

Europa Clipper Asks Big Questions Of The Jovian Moon

Are we alone? While we certainly have lots of strange lifeforms to choose from as companions here on our blue marble, we have yet to know if there’s anything else alive out there in the vastness of space. One of the most promising places to look in our own solar neighborhood is Europa.

People in bunny suits swarm underneath the main section of the Europa Clipper. It is predominantly white, with various tubes and structures of silver metal protruding and many pieces of yellow kapton tape are visible. A large orange module is strapped to the side around the middle of the semi-cylindrical craft. Several other dark orange metallic plates that are much smaller adorn various pieces of the craft. It looks both chonky and delicate at the same time. Underneath its icy surface, Europa appears to have a sea that contains twice as much water as we have here on Earth. Launching later this year and arriving in 2030, NASA’s Europa Clipper will provide us with our most up-close-and-personal look at the Jovian Moon yet. In conjunction with observations from the ESA’s Jupiter Icy Moons Explorer (JUICE), scientists hope to gain enough new data to see if the conditions are right for life.

Given the massive amounts of radiation in the Jovian system, Europa Clipper will do 50 flybys of the moon over the course of four years to reduce damage to instruments as well as give it windows to transmit data back to Earth with less interference. With enough planning and luck, the mission could find promising sites for a future lander that might be able to better answer the question of if there actually is life on other worlds.

Some of the other moons around Jupiter could host life, like Io. Looking for life a little closer? How about on our nearest neighbor, Venus, or the ever popular Mars?

Complex Organic Chemistry In Sulfuric Acid And Life On Venus

Finding extraterrestrial life in any form would be truly one of the largest discoveries in humankind’s history, yet after decades of scouring the surface of Mars and investigating other bodies like asteroids, we still have found no evidence. While we generally assume that we’re looking for carbon-based lifeforms in a water-rich environment like Jupiter’s moon Europa, what if complex organic chemistry would be just as happy with sulfuric acid (H2SO4) as solvent rather than dihydrogen monoxide (H2O)? This is the premise behind a range of recent studies, with a newly published research article in Astrobiology by [Maxwell D. Seager] and colleagues lending credence to this idea.

Previous studies have shown that organic chemistry in concentrated sulfuric acid is possible, and that nucleic acid bases – including adenosine, cytosine, guanine, thymine and uracil which form DNA – are also stable in this environment, which is similar to that of the Venusian clouds at an altitude where air pressure is roughly one atmosphere. In this new article, twenty amino acids were exposed to the concentrations of sulfuric acid usually found on Venus, at 98% and 81%, with the rest being water. Of these, 11 were unchanged after 4 weeks, 9 were reactive on their side chains, much like they would have been in pure water. Only tryptophan ended up being unstable, but as the researchers note, not all amino acids are stable in water either.

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SHERLOC And The Search For Life On Mars

Humanity has been wondering about whether life exists beyond our little backwater planet for so long that we’ve developed a kind of cultural bias as to how the answer to this central question will be revealed. Most of us probably imagine that NASA or some other space agency will schedule a press conference, an assembled panel of scientific luminaries will announce the findings, and newspapers around the world will blare “WE ARE NOT ALONE!” headlines. We’ve all seen that movie before, so that’s the way it has to be, right?

Probably not. Short of an improbable event like an alien spacecraft landing while a Google Street View car was driving by or receiving an unambiguously intelligent radio message from the stars, the conclusion that life exists now or once did outside our particular gravity well is likely to be reached in a piecewise process, an accretion of evidence built up over a long time until on balance, the only reasonable conclusion is that we are not alone. And that’s exactly what the announcement at the end of last year that the Mars rover Perseverance had discovered evidence of organic molecules in the rocks of Jezero crater was — another piece of the puzzle, and another step toward answering the fundamental question of the uniqueness of life.

Discovering organic molecules on Mars is far from proof that life once existed there. But it’s a step on the way, as well as a great excuse to look into the scientific principles and engineering of the instruments that made this discovery possible — the whimsically named SHERLOC and WATSON.

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