It Appears That Enceladus is Even More Habitable Than we Thought

Phosphorus is likely abundant in the waters of Enceladus. Credit: Southwest Research Institute

The problem with looking for life on other worlds is that we only know of one planet with life. Earth has a wondrous variety of living creatures, but they all evolved on a single world, and their heritage stems from a single tree of life. So astrobiologists have to be both clever and careful when looking for habitable worlds, even when they narrow the possibilities to life similar to ours.

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Shallow Pockets of Water Under the ice on Europa Could Bring Life Close to its Surface

This artist’s conception shows how double ridges on the surface of Jupiter’s moon Europa may form over shallow, refreezing water pockets within the ice shell. This mechanism is based on the study of an analogous double ridge feature found on Earth’s Greenland Ice Sheet. (Image credit: Justice Blaine Wainwright)

Beneath the surface of Jupiter’s icy moon Europa, there’s an ocean up to 100 km (62 mi) deep that has two to three times the volume of every ocean on Earth combined. Even more exciting is how this ocean is subject to hydrothermal activity, which means it may have all the necessary ingredients for life. Because of this, Europa is considered one of the most likely places for extraterrestrial life (beyond Mars). Hence, mission planners and astrobiologists are eager to send a mission there to study it closer.

Unfortunately, Europa’s icy surface makes the possibility of sampling this ocean rather difficult. According to the two predominant models for Europa’s structure, the ice sheet could be a few hundred meters to several dozen kilometers thick. Luckily, new research by a team from Stanford University has shown that Europa’s icy shell may have an abundance of water pockets inside, as indicated by features on the surface that look remarkably like icy ridges here on Earth.

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Why Would an Alien Civilization Send Out Von Neumann Probes? Lots of Reasons, says a new Study

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In 1948-49, mathematician, physicist, computer scientist, and engineer John von Neumann introduced the world to his idea of “Universal Assemblers,” a species of self-replicating robots. Von Neumann’s ideas and notes were later compiled in a book titled “Theory of self-reproducing automata,” published in 1966 (after his death). In time, this theory would have implications for the Search for Extraterrestrial Intelligence (SETI), with theorists stating that advanced intelligence must have deployed such probes already.

The reasons and technical challenges of taking the self-replicating probe route are explored in a recent paper by Gregory L. Matloff, an associate professor at the New York City College of Technology (NYCCT). In addition to exploring why an advanced species would opt to explore the galaxy using Von Neumann probes (which could include us someday), he explored possible methods for interstellar travel, strategies for exploration, and where these probes might be found.

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A Technique to Find Oceans on Other Worlds

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

You could say that the study of extrasolar planets is in a phase of transition of late. To date, 4,525 exoplanets have been confirmed in 3,357 systems, with another 7,761 candidates awaiting confirmation. As a result, exoplanet studies have been moving away from the discovery process and towards characterization, where follow-up observations of exoplanets are conducted to learn more about their atmospheres and environments.

In the process, exoplanet researchers hope to see if any of these planets possess the necessary ingredients for life as we know it. Recently, a pair of researchers from Northern Arizona University, with support from the NASA Astrobiology Institute’s Virtual Planetary Laboratory (VPL), developed a technique for finding oceans on exoplanets. The ability to find water on other planets, a key ingredient in life on Earth, will go a long way towards finding extraterrestrial life.

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To Take the Best Direct Images of Exoplanets With Space Telescopes, we’re Going to Want Starshades

Between 2021 and 2024, the James Webb (JWST) and Nancy Grace Roman (RST) space telescopes will be launched to space. As the successors to multiple observatories (like Hubble, Kepler, Spitzer, and others), these missions will carry out some of the most ambitious astronomical surveys ever mounted. This will range from the discovery and characterization of extrasolar planets to investigating the mysteries of Dark Matter and Dark Energy.

In addition to advanced imaging capabilities and high sensitivity, both instruments also carry coronagraphs – instruments that suppress obscuring starlight so exoplanets can be detected and observed directly. According to a selection of papers recently published by the Journal of Astronomical Telescopes, Instruments, and Systems (JATIS), we’re going to need more of these instruments if we truly want to really study exoplanets in detail.

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New Technique to Search for Life, Whether or not it’s Similar to Earth Life

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

In 1960, the first survey dedicated to the Search for Extraterrestrial Intelligence (SETI) was mounted at the Green Bank Observatory in West Virginia. This was Project Ozma, which was the brainchild of famed astronomer and SETI pioneer Frank Drake (for whom the Drake Equation is named). Since then, the collective efforts to find evidence of life beyond Earth have coalesced to create a new field of study known as astrobiology.

The search for extraterrestrial life has been the subject of renewed interest thanks to the thousands of exoplanets that have been discovered in recent years. Unfortunately, our efforts are still heavily constrained by our limited frame of reference. However, a new tool developed by a team of researchers from the University of Glasgow and Arizona State University (ASU) could point the way towards life in all of its forms!

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The Same Technology Could Search for Microbes in Mars Rocks or Under the ice on Europa

Credit: NASA/JPL-Caltech

Ever since it landed in the Jezero Crater on Feb. 18th, 2021, the Perseverance rover has been prepping its scientific instruments to begin searching for signs of past life on the Red Planet. These include spectrometers that will scan Martian rocks for organics and minerals that form in the presence of water and a caching system that will store samples of Martian soil and rock for retrieval by a future mission.

These telltale indicators could be signs of past life, which would most likely take the form of fossilized microbes. In the near future, a similar instrument could be used to search for present-day extraterrestrial life. It’s known as the Wireline Analysis Tool for the Subsurface Observation of Northern ice sheets (WATSON), and could be used to find evidence of life inside “ocean worlds” like Europa, Enceladus, and Titan.

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Scientists Have Re-Analyzed Their Data and Still See a Signal of Phosphine at Venus. Just Less of it

In September, an international team announced that based on data obtained by the Atacama Millimeter-submillimeter Array (ALMA) in Chile and the James Clerk Maxwell Telescope (JCMT) in Hawaii, they had discovered phosphine gas (PH3) in the atmosphere of Venus. The news was met with its fair share of skepticism and controversy since phosphine is considered a possible indication of life (aka. a biosignature).

Shortly thereafter, a series of papers were published that questioned the observations and conclusions, with one team going as far as to say there was “no phosphine” in Venus’ atmosphere at all. Luckily, after re-analyzing the ALMA data, the team responsible for the original discovery concluded that there is indeed phosphine in the cloud tops of Venus – just not as much as they initially thought.

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Europa’s Nightside Glows in the Dark

This illustration of Jupiter's moon Europa shows how the icy surface may glow on its nightside, the side facing away from the Sun. Variations in the glow and the color of the glow itself could reveal information about the composition of ice on Europa's surface. Credit: NASA/JPL-Caltech

In a few years, NASA will be sending a spacecraft to explore Jupiter’s icy moon Europa. Known as the Europa Clipper mission, this orbiter will examine the surface more closely to search for plume activity and evidence of biosignatures. Such a find could answer the burning question of whether or not there is life within this moon, which is something scientists have speculated about since the 1970s.

In anticipation of this mission, scientists continue to anticipate what it will find once it gets there. For instance, scientists from NASA’s Jet Propulsion Laboratory recently conducted a study that showed how Europa might glow in the dark. This could be the result of Europa constantly being pummeled with high-energy radiation from Jupiter’s magnetic field, the study of which could tell scientists more about the composition of Europa’s ice.

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Titan’s Atmosphere Has All the Ingredients For Life. But Not Life as We Know It

A global mosaic of the surface of Titan, thanks to the infrared eyes of the Cassini spacecraft. Image Credit: NASA/JPL-Caltech/University of Nantes/University of Arizona
A global mosaic of the surface of Titan, thanks to the infrared eyes of the Cassini spacecraft. Image Credit: NASA/JPL-Caltech/University of Nantes/University of Arizona

Using the Atacama Large Millimeter/submillimeter Array (ALMA), a team of scientists has identified a mysterious molecule in Titan’s atmosphere. It’s called cyclopropenylidene (C3H2), a simple carbon-based compound that has never been seen in an atmosphere before. According to the team’s study published in The Astronomical Journal, this molecule could be a precursor to more complex compounds that could indicate possible life on Titan.

Similarly, Dr. Catherine Neish of the University of Western Ontario’s Institute for Earth and Space Exploration (Western Space) and her colleagues in the European Space Agency (ESA) found that Titan has other chemicals that could be the ingredients for exotic life forms. In their study, which appeared in Astronomy & Astrophysics, they present Cassini mission data that revealed the composition of impact craters on Titan’s surface.

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