Will Europa finally answer, ‘Are we alone?’

While NASA’s much-lauded Space Launch System stands ready for its maiden flight later this month with the goal of sending astronauts back to the Moon in the next few years, our gazes once again turn to the stars as we continue to ask the question that has plagued humankind since time immemorial: Are we alone? While there are several solar system locales that we can choose from to conduct our search for life beyond Earth, to include Mars and Saturn’s moons, Titan and Enceladus, one planetary body orbiting the largest planet in the solar system has peaked the interest of scientists since the 1970s.

Jupiter’s second Galilean Moon, Europa, with its interior ocean, predominantly crater-less surface, and crisscrosses of cracks and ridges spanning entire hemispheres, makes it one of the most fascinating planetary bodies ever observed. These unique geologic features are possibly indicative of liquid water traveling to the surface from its deep ocean, making Europa a hot spot for the exploration and study of life beyond Earth, also known as astrobiology.

False color mosaic of Europa taken by NASA’s Galileo spacecraft. (Credit: NASA/JPL-Caltech/SETI Institute)

“Europa may be one of the few accessible places whether life could originate and persist,” says Dr. Michael Manga, a geophysicist and Professor in the Department of Earth and Planetary Science at UC Berkeley. “Its evolution and dynamics are fascinating, some similarities but also fundamental differences from Earth.”

Scientists hypothesize that Europa’s icy outer shell is 15 to 25 kilometers (10 to 15 miles) thick that floats on an ocean 60 to 150 kilometers (40 to 100 miles) deep. While there is strong evidence that Saturn’s moon, Enceladus, also has a interior ocean, Europa’s ocean is believed to potentially house double the amount of water as all of Earth’s oceans combined, despite Europa being only a quarter of Earth’s diameter.

“Europa’s surface composition and some of its geologic features suggest that ocean water somehow moves through the shell and reaches the surface,” says Dr. Alyssa Rhoden, who is a Principal Scientist within the Planetary Science Directorate at the Southwest Research Institute (SwRI) in Boulder, Colorado. “If that is true, it means that nutrients and energy can cycle between the ocean, ice shell, and surface, and that can be beneficial for life.”

Artist’s illustration of interaction between Europa’s interior ocean and its outer ice shell (foreground) accompanied by Jupiter (right) and Io (left). (Credit: NASA/JPL-Caltech)

There is already evidence that this liquid water has made it to the surface in the form of what is known as “chaos terrain”, which is highly disrupted topography where blocks of ice have broken off, shifted, and then refroze to the surface due to the lack of atmosphere and being exposed directly to the vacuum of space. One example of chaos terrain on Europa is Conamara Chaos, which was imaged by NASA’s Galileo spacecraft and later reconstructed to show what it looked like before the surface disruption took place.

Conamara Chaos on Europa demonstrating surface disruption potentially from liquid water making its way to the surface. (Credit: NASA/NASA JPL/ University of Arizona)

Europa’s vast ocean swirls beneath its icy crust despite the moon’s incredible distance from the Sun, putting it well beyond our star’s habitable zone, which is the sweet spot where liquid water can exist on a planet’s surface. Instead, this ocean exists from what is known as tidal heating, or the constant stretching and compressing the small moon endures as it orbits the much more massive Jupiter throughout its elliptical orbit. Along with Jupiter, Europa is also being constantly tugged by Jupiter’s moons, Io and Ganymede, the first and third Galilean satellites, respectively. This tidal heating leads to friction within Europa’s core, corresponding to heat and ultimately melting the inner ice into what is now Europa’s massive ocean.

“I find Europa captivating because its geology, interior, and orbit are all connected through the process of tides,” says Dr. Rhoden. “Europa’s gravitational relationship with Jupiter, and its neighboring moons, are responsible for creating this complex, active world. Each aspect you study is connected to the others, so there are a lot of ways to investigate the processes at work and a lot to get curious about.”

While Europa has been studied in-depth with past space missions, most notably NASA’s Galileo mission of the 1990s and early 2000s, NASA’s upcoming Europa Clipper mission proves to be a gamechanger in terms of our understanding of this fantastic icy moon, slated to launch in late 2024 with orbital insertion around Jupiter being accomplished in early 2030. The primary goal of Clipper is to ascertain the habitability potential for locations below the icy surface while making almost 50 extremely close flybys of the icy moon, some as low as 25 kilometers (16 miles).

“I started researching Europa 22 years ago, and I’ve had the same images to work with the entire time,” says Dr. Rhoden. “So, I would say I am EXTREMELY excited for the new data sets that will be delivered by Clipper. As for habitability, there are probably many ways it will inform habitability, but what I am most interested to see is evidence of liquid water within the ice shell.”

Artist’s illustration of Europa Clipper in orbit around Europa. (Credit: NASA/JPL-Caltech)

Given how water is the reason why life thrives here on Earth, what kinds of life could we find traversing Europa’s interior ocean? While Dr. Rhoden jokingly says, “Space whales, obviously”, Dr. Manga is less optimistic, saying a gut feeling tells him there’s no life, but concludes by saying that it will take samples collected from a lander to know for sure.

Will Europa and its vast ocean finally answer the longstanding questions of whether we are alone in the universe? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

Watch OSIRIS-REx's Complex Orbital Path Around Bennu in This Cool Animation

OSIRIS-REx mission timeline. Credit: NASA.

The OSIRIS-REx spacecraft conducted a two-year reconnaissance and sample collection at the asteroid Bennu, providing crucial data about the 500-meter-wide potentially hazardous rubble pile/space rock. When OSIRIS-REx arrived on Dec. 3, 2018, it needed some tricky navigation and precise maneuvers to make the mission work.

Experts at NASA Goddard’s Scientific Visualization Studio created an amazing visualization of the path the spacecraft took during its investigations. A short film called “A Web Around Asteroid Bennu” highlights the complexity of the mission, and the film is being shown at the SIGGRAPH computer graphics conference in Vancouver, British Columbia, Canada, a festival honoring standout works of computer animated storytelling.

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Dwarf Galaxies Found Without Influence From Dark Matter

Dwarf galaxy in Fornax.
The dwarf galaxy NGC1427A flies through the Fornax galaxy cluster and undergoes disturbances which would not be possible if this galaxy were surrounded by a heavy and extended dark matter halo, as required by standard cosmology. Courtesy ESO.

Ask astronomers about dark matter and one of the things they talk about is that this invisible, mysterious “stuff” permeates the universe. In particular, it exists in halos surrounding most galaxies. The mass of the halo exerts a strong gravitational influence on the galaxy itself, as well as on others in the neighborhood. That’s pretty much the standard view of dark matter and its influence on galaxies. However, there are problems with the idea of those halos. Apparently, some oddly shaped dwarf galaxies exist that look like they have no halos. How could this be? Do they represent an observationally induced challenge to the prevailing ideas about dark matter halos?

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Jupiter Missions Could Also Help Search for Dark Matter

In a recent study published in the Journal of High Energy Physics, two researchers from Brown University demonstrated how data from past missions to Jupiter can help scientists examine dark matter, one of the most mysterious phenomena in the universe. The reason past Jupiter missions were chosen is due to the extensive amount of data gathered about the largest planet in the solar system, most notably from the Galileo and Juno orbiters. The elusive nature and composition of dark matter continues to elude scientists, both figuratively and literally, because it does not emit any light. So why do scientists continue to study this mysterious—and completely invisible—phenomena?

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I Asked an AI to Dream the Solar System as Food

Jupiter, as a Sandwich. Credit: Midjourney AI
Jupiter, as a Sandwich. Credit: Midjourney AI

As soon as I saw these new artificial intelligence image creation tools, like DALL-E, I wanted to see how well they’d work for generating space and astronomy images. I’m still on the waiting list for DALL-E 2, so I don’t have any feedback to give there, but I signed up for Midjourney AI, played around with the free account, and then signed up for a full paid account, so I could test out its capabilities.

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Masten Space is Building a Lunar Lander for NASA. Also, They Just Filed for Bankruptcy

Artist's rendering of the Masten XL-1 lander. Credit: Masten Space Systems

If you’re a fan of the commercial space industry (aka. NewSpace), then the name Masten Space Systems is sure to ring a bell. For years, this California-based aerospace company has been developing delivery systems to accommodate payloads to the Moon, Mars, and beyond. This included Xoie, the lander concept that won the $1 million Northrop Grumman Lunar X-Prize in 2009, their Xombie and Xodiac reusable terrestrial landers, and the in-Flight Alumina Spray Technique (FAST) that would allow lunar landers to create their own landing pads.

But perhaps their biggest feat was the Xelene Lunar Lander (XL-1) that they developed in partnership with the NASA Lunar CATALYST program. This lander was one of several robotic systems enlisted by NASA to deliver cargo to the Moon in support of the Artemis Program. This included the Masten-1 mission, which was scheduled to land a payload Moon’s southern polar region in 2023. The company was scheduled to make a second delivery (Masten-2) by 2024, one year before the first Artemis astronauts arrived. But according to a statement issued on July 28th, the company has filed for Chapter 11 and is bankrupt!

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NASA’s Space Launch System Gets Tentative Launch Date of August 29th

NASA has announced tentative placeholder launch dates for its beast of a rocket, the Space Launch System (SLS), on its maiden flight to deep space. While work still needs to be accomplished to ensure its launch, the tentative dates are currently August 29th, September 2nd, and September 5th. While NASA stressed these are not set dates, the announcement nonetheless puts SLS closer than ever to flight.

The maiden launch of the most powerful rocket ever built comes after years of budget increases and delays. Funding for SLS was approximately $1.5 billion in 2011 but has increased almost every year until it hit $2.5 billion in 2021. This came after Congress mandated SLS “operational capability…not later than December 31, 2016”, but has faced countless delays since then due to audits and poor management.

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Did you Want More Scientific Information About the First set of Images From JWST? Fill Your Boots

James Webb's first images! Credit: NASA/ESA/CSA/STScI

On July 12th, 2022, NASA and its partner agencies released the first James Webb Space Telescope (JWST) observations to the public. These included images and spectra obtained after Webb’s commissioning phase, which included the most-detailed views of galaxy clusters, gravitational lenses, nebulae, merging galaxies, and spectra from an exoplanet’s atmosphere. Less than a month after their release, a paper titled “The JWST Early Release Observations” has been made available that describes the observations and the scientific process that went into making them.

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The Tharsis Region of Mars is Peppered With These Strange Pit Craters. Now They’ve Been Found Elsewhere

An Atypical Pit Crater in ancient terrain near Elysium Mons, as seen by the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/UArizona.

Pit craters are found on solid bodies throughout our Solar System, including Earth, Venus, the Moon, and Mars. These craters – which are not formed by impacts — can be indications of underground lava tubes, which are created when the top of a stream of molten rock solidifies and the lava inside drains away, leaving a hollow tube of rock. If a portion of the roof of the tube is unsupported, parts of it may fall in, making a hole or a pit along the lava tube’s path.

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