Tag: Europa

A Reprieve for Space Science?

View of WFIRST focusing on supernova SN1995E in NGC 2441. The high-priority but embattled space telescope would, if congressional support continues, add greatly to knowledge about dark energy and dark matter, supernovae, and exoplanets.  (NASA)


A quick update on a recent column about whether our “golden age” of space science and discovery was in peril because of cost overruns and Trump administration budget priorities that emphasized human space travel over science.

The 2018 omnibus spending bill that was passed Wednesday night by the House of Representatives and Thursday night by the Senate represents a major push back against the administration’s earlier NASA budget proposals.  Not only would the agency receive $1.6 billion more funding than proposed by the administration, but numerous projects that had been specifically eliminated in that proposal are back among the living.

They include four Earth science satellites, a lander to accompany the Europa Clipper mission to that potentially habitable moon and, perhaps most important, the Wide Field Infrared Survey Telescope (WFIRST) space telescope.

Funding for that mission, which was the top priority of the space science community and the National Academy of Sciences for the 2020s, was eliminated in the proposed 2019 Trump budget, but WFIRST received $150 million in the just-passed omnibus bill.

A report accompanying the omnibus bill is silent about the proposed cancellation and instructs NASA to provide to Congress in 60 days a cost estimate for the full life cycle of the mission, including any additions that might be needed.  So there appears to be a strong congressional desire to see WFIRST launch and operate.

Still hanging fire is the fate of the James Webb Space Telescope, which has fallen behind schedule again and is in danger of crossing the $8 billion cap put into place by Congress in 2011.  NASA officials said this week that they will soon announce their determination about whether a breach of the program’s cost cap will occur as a result of further delays.

NASA has a fleet of 18 Earth science missions in space, supported by aircraft, ships and ground observations. Together they have revolutionized understanding of the planet’s atmosphere, the oceans, the climate and weather. The Obama administration emphasized Earth studies, but the Trump administration has sought to eliminate future Earth missions. This visualization shows the NASA fleet in 2017, from low Earth orbit all the way out to the DSCOVR satellite taking in the million-mile view.

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Certain Big, Charged Molecules Are Universal to Life on Earth. Can They Help Detect It In The Far Solar System?


This article of mine, slightly tweaked for Many Worlds, first appeared today (July 6)  in Astrobiology Magazine,  www.astrobio.net

NASA’s Cassini spacecraft completed its deepest-ever dive through the icy plume of Enceladus on Oct. 28, 2015. The spacecraft did not have instruments that could detect life, but missions competing for NASA New Frontiers funding will — raising the thorny question of how life might be detected. (NASA/JPL-Caltech)

As NASA inches closer to launching new missions to the Solar System’s outer moons in search of life, scientists are renewing their focus on developing a set of universal characteristics of life that can be measured.

There is much debate about what might be considered a clear sign of life, in part, because there are so many definitions separating the animate from the inanimate.

NASA’s prospective missions to promising spots on Europa, Enceladus and Titan have their individual approaches to detecting life, but one respected voice in the field says there is a better way that’s far less prone to false positives.

Noted chemist and astrobiologist Steven Benner says life’s signature is not necessarily found in the presence of particular elements and compounds, nor in its effects on the surrounding environment, and is certainly not something visible to the naked eye (or even a sophisticated camera).

Rather, life can be viewed as a structure, a molecular backbone that Benner and his group, Foundation for Applied Molecular Evolution (FfAME), have identified as the common inheritance of all living things. Its central function is to enable what origin-of-life scientists generally see as an essential dynamic in the onset of life and its increased complexity and spread: Darwinian evolution via transfer of information, mutation and the transfer of those mutations.

“What we’re looking for is a universal molecular bio-signature, and it does exist in water,” says Benner. “You want a genetic molecule that can change physical conditions without changing physical properties — like DNA and RNA can do.”

Steven Benner, director of the Foundation for Applied Molecular Evolution or FfAME. (SETI)

Looking for DNA or RNA on an icy moon, or elsewhere would presuppose life like our own — and life that has already done quite a bit of evolving.

A more general approach is to find a linear polymer (a large molecule, or macromolecule, composed of many repeated subunits, of which DNA and RNA are types) with an electrical charge. That, he said, is a structure that is universal to life, and it can be detected.… Read more “Certain Big, Charged Molecules Are Universal to Life on Earth. Can They Help Detect It In The Far Solar System?”

Planetary Protection is a "Wicked" Problem

The Viking landers were baked for 30 hours after assembly, a dry heat sterilization that is considered the gold standard for planetary protection.  Before the baking, the landers were given a preliminary cleaning to reduce the number of potential microbial spores.  The levels achieved with that preliminary cleaning are similar to what is now required for a mission to Mars unless the destination is an area known to be suitable for Martian life.  In that case, a sterilizing equivalent to the Viking baking is required.  (NASA)

The only time that a formally designated NASA “life detection” mission was flown to another planet or moon was when the two Viking landers headed to Mars forty years ago.

The odds of finding some kind of Martian life seemed so promising at the time that there was little dispute about how much energy, money and care should be allocated to making sure the capsule would not be carrying any Earth life to the planet.  And so after the two landers had been assembled, they were baked at more than 250 °F for three days to sterilize any parts that would come into contact with Mars.

Although the two landers successfully touched down on the Martian surface and did some impressive science, the life detection portion of the mission was something of a fiasco — with conflict, controversy and ultimately quite a bit of confusion.

Clearly, scientists did not yet know enough about how to search for life beyond Earth and the confounding results pretty much eliminated life-detection from NASA’s missions for decades.

But scientific and technological advances of the last ten years have put life detection squarely back on the agenda — in terms of future searches for fossil biosignatures on Mars and for potential life surviving in the oceans of Europa and Enceladus.  What’s more, both NASA and private space companies talk seriously of sending humans to Mars in the not-too-distant future.

With so many missions being planned, developed and proposed for solar system planets and moons, the issue of planetary protection has also gained a higher profile.  It seems to have become more contentious and to some seems far less straight-forward as it used to be.

A broad consensus appears to remain that bringing Earth life to another planet or moon, especially if it is potentially habitable, is a real possibility that is both scientifically and ethically fraught. But there are rumblings about just how much time, money and attention needs to be brought to satisfying the requirements of “planetary protection.”

In fact, it has become a sufficiently significant question that the first plenary session of the recent Astrobiology Science Conference in Mesa, Arizona was dedicated to it. … Read more “Planetary Protection is a "Wicked" Problem”

NASA Panel Supports Life-Detecting Lander for Europa; Updated

Artist conception of water vapor plumes coming from beneath the thick ice of Jupiter’s moon Europa. The plumes have not been definitively detected, but Hubble Space Telescope images make public earlier this month appear to show plume activity in an area where it was detected once before.  How will this finding affect decision-making about a potential NASA Europa lander mission? (NASA)

As I prepare for the Astrobiology Science Conference (Abscicon) next week in Arizona, I’m struck by how many speakers will be discussing Europa missions, Europa science, ocean worlds and habitability under ice.  NASA’s Europa Clipper mission to orbit that moon, scheduled for launch to the Jupiter system in the mid 2020s, explains part of the interest, but so too does the unsettled fate of the Europa lander concept.

The NASA Science Definition Team that studied the Europa lander project will both give a science talk at the conference and hold an afternoon-long science community meeting on their conclusions.  The team argued that landing on Europa holds enormous scientific promise, most especially in the search for life beyond Earth.

But since the Europa lander SDT wrote its report and took its conclusions public early this year, the landscape has changed substantially.  First, in March, the Trump Administration 2018 budget eliminated funding for the lander project.  More than half a billion dollars have been spent on Europa lander research and development, but the full project was considered to be too expensive by the White House.

Administration budget proposals and what ultimately become budget reality can be quite different, and as soon as the Europa lander was cancelled supporters in Congress pushed back.  Rep. John Culberson (R-Tex.) and chair of the House subcommittee that oversees the NASA budget, replied to the proposed cancellation by saying “NASA is a strategic national asset and I have no doubt NASA will receive sufficient funding to complete the most important missions identified by the science community, including seeking out life in the oceans of Europa.”

More recently, researchers announced additional detections of plumes of water vapor apparently coming out of Europa — plumes in the same location as a previous apparent detection.  The observing team said they were confident the difficult observation was indeed water vapor, but remained less than 100 percent certain.  (Unlike for the detection of a water plume on Saturn’s moon Enceladeus, which the Cassini spacecraft photographed, measured and flew through.)

So while suffering a serious blow in the budgeting process, the case for a Europa lander has gotten considerably stronger from a science and logistics perspective. 

Read more “NASA Panel Supports Life-Detecting Lander for Europa; Updated”

NASA Panel Supports Life-Detecting Lander for Europa

Artist rendering of a potential life-detecting lander mission to Europa that would follow on the Europa Clipper orbiter mission that is scheduled to launch in the 2020s.. In the background is Jupiter. (NASA/JPL/Caltech)

It has been four long decades since NASA has sent an officially-designated life detection mission into space.  The confused results of the Viking missions to Mars in the mid 1970s were so controversial and contradictory that scientists — or the agency at least — concluded that the knowledge needed to convincingly search for extraterrestrial life wasn’t available yet.

But now, a panel of scientists and engineers brought together by NASA has studied a proposal to send a lander to Jupiter’s moon Europa and, among other tasks, return to the effort of life-detection.

In their recommendation, in fact, the NASA-appointed Science Definition Team said that the primary goal of the mission would be “to search for evidence of life on Europa.”

The other goals are to assess the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean.

Scientists agree that the evidence is quite strong that Europa, which is slightly smaller than Earth’s
moon, has a global saltwater ocean beneath its deep ice crust, and that it contains twice as much water as exists on Earth.

For the ocean to be liquid there must be substantial sources of heat — from tidal heating based on the shape of its orbits, or from heat emanating from radioactive decay and entering the ocean through hydrothermal vents.  All could potentially provide an environment where life could emerge and survive.

Kevin Hand of the Jet Propulsion Laboratory is a specialist in icy worlds and is deputy project scientist for the Europa project.  He was one of the co-chairs of the Science Definition Team (SDT) and he said the group was ever mindful of the complicated history of the Viking missions.  He said that some people called Viking a “failure” because it did not clearly identify life, but he described that view as “entirely unscientific.”

“It would be misguided to set out to ‘find life’,” he told me.  “The real objective is to test an hypothesis – one we have that if you bring together the conditions for life as we know them, then they might come together and life can inhabit the environment.

“As far as we can tell, Europa has the water, the elements and the energy needed to create a habitable world. … Read more “NASA Panel Supports Life-Detecting Lander for Europa”

More Evidence of Water Plumes On Europa Increases Confidence That They’re For Real

 Figure 2: This composite image shows suspected plumes of water vapor erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The Hubble data were taken on January 26, 2014. The image of Europa, superimposed on the Hubble data, is assembled from data from the Galileo and Voyager missions. Credits: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center Image comparison of 2014 transit and 2012 Europa aurora observations

This composite image shows suspected plumes of water vapor erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The Hubble data were taken on January 2014, and appear to show plumes that spit out as much as 125 miles.  The image of Europa, superimposed on the Hubble data, is assembled from data from the Galileo and Voyager missions. (NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center)

Europa is a moon no bigger than our own and is covered by deep layers of ice, but it brings with it a world of promise.  Science fiction master and sometimes space visionary Arthur C. Clarke, after all,  named it as the most likely spot in our solar system to harbor life, and wrote a “2001: A Space Odyssey”  follow-up based in part on that premise.

Many in the planetary science and astrobiology communities are similarly inclined and have supported a specifically Europa mission geared to learning more about what is generally considered to be a large ocean beneath that ice.

Along the way, Europa became the only object deemed by Congress to be an obligatory NASA destination, and formal plans for such a voyage have been under way — however slowly — for several years.  Formal development of the “Europa Clipper” flyby project began last year, after a half decade of conceptual work.

The logic for the flyby got a major boost on Monday when a team using the Hubble Space Telescope reported that they had most likely detected plumes of water erupting out of Europa on three separate occasions.

Because of the difficulty of the observation — and the fact that plumes were found on 3 out of 10 passes — nobody was willing to claim that the finding was definitive.  But coupled with an earlier identification of a Europa plume by a different team using a different technique, the probability that the plumes are real is getting pretty high.

And if there really are plumes of water vapor or ice crystals being pushed through Europa’s thick surface of ice, then the implications for the search for signs of habitability and of life on Europa are enormous.

“Europa is surely one of the most compelling astrobiological targets in solar system with its apparent saline oceans,” said William Sparks, an astronomer with Space Telescope Science Institute in Baltimore and lead author of the Europa paper, to be published in The Astrophysical Journal.… Read more “More Evidence of Water Plumes On Europa Increases Confidence That They’re For Real”

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