Author: Marc Kaufman (page 3 of 16)

NExSS 2.0

Finding new worlds can be an individual effort, a team effort, an institutional effort. The same can be said for characterizing exoplanets and understanding how they are affected by their suns and other planets in their solar systems. When it comes to the search for possible life on exoplanets, the questions and challenges are too great for anything but a community. NASA’s NExSS initiative has been an effort to help organize, cross-fertilize and promote that community. This artist’s concept Kepler-47, the first two-star systems with multiple planets orbiting the two suns, suggests just how difficult the road ahead will be. ( NASA/JPL-Caltech/T. Pyle)

 

The Nexus for Exoplanet System Science, or “NExSS,”  began four years ago as a NASA initiative to bring together a wide range of scientists involved generally in the search for life on planets outside our solar system.

With teams from seventeen academic and NASA centers, NExSS was founded on the conviction that this search needed scientists from a range of disciplines working in collaboration to address the basic questions of the fast-growing field.

Among the key goals:  to investigate just how different, or how similar, different exoplanets are from each other; to determine what components are present on particular exoplanets and especially in their atmospheres (if they have one);  to learn how the stars and neighboring exoplanets interact to support (or not support) the potential of life;  to better understand how the initial formation of planets affects habitability, and what role climate plays as well.

Then there’s the  question that all the others feed in to:  what might scientists look for in terms of signatures of life on distant planets?

Not questions that can be answered alone by the often “stove-piped” science disciplines — where a scientist knows his or her astrophysics or geology or geochemistry very well, but is uncomfortable and unschooled in how other disciplines might be essential to understanding the big questions of exoplanets.

 

The original NExSS team was selected from groups that had won NASA grants and might want to collaborate with other scientists with overlapping interests and goals  but often from different disciplines. (NASA)

The original idea for this kind of interdisciplinary group came out of NASA’s Astrobiology Program, and especially from NASA astrobiology director Mary Voytek and colleague Shawn Domogal-Goldman of the Goddard Space Flight Center, as well as Doug Hudgins of NASA Astrophysics.  It was something of a gamble, since scientists who joined would essentially volunteer their time and work and would be asked to collaborate with other scientists in often new ways.… Read more

Many Worlds Interruptus

I regret that I haven’t been able to file Many Worlds posts for a while, but here is why:

 

X-ray of my wife’s broken ankle

The broken part of my wife’s ankle is the traingle of bone floating near the tibia, to which it should be attached.

She’s had surgery and isn’t supposed to be walking on it for a month.  But now, with the help of several screws holding parts together, she is on the mend.

New posts coming next week!

 … Read more

Great Nations Need Great Observatories

This new image from NASA’s Hubble Space Telescope, shows the tentacled Southern Crab Nebula. The nebula, officially known as Hen 2-104, appears to have two nested hourglass-shaped structures that were sculpted by a whirling pair of stars in a binary system. The duo consists of an aging red giant star and a burned-out star, a white dwarf. The red giant is shedding its outer layers and some of this ejected material is attracted by the gravity of the companion white dwarf. The result is that both stars are embedded in a flat disk of gas stretching between them. This belt of material constricts the outflow of gas so that it only speeds away above and below the disk. The result is an hourglass-shaped nebula. The bubbles of gas and dust appear brightest at the edges, giving the illusion of crab leg structures. These “legs” are likely to be the places where the outflow slams into surrounding interstellar gas and dust, or possibly material which was earlier lost by the red giant star.  (NASA and ESA)

The Hubble Space Telescope, arguably the jewel in the crown of NASA’s science missions, was launched 29 years ago.  It has been providing scientists and the public with a steady stream of previously unimagined insights about the cosmos — plus those jaw-dropping, very high-resolution images like the one above — pretty much ever since.

It has also provided the best example to date of what humans can do in space with its five repair and upgrade missions.  It did indeed launch to great skepticism, especially after a near fatal flaw was found in its key mirror.  It was also considered over budget at launch, way behind schedule and questionable scientifically and had to be fixed in orbit 353 miles into space.

The Hubble Space Telescope after its second repair and upgrade mission in 1998. (NASA)

But almost three decades into its mission now — and with decades more service likely — it clearly shows what an exceedingly ambitious project can deliver and the level of excellence that NASA, its European Space Agency partner and space scientists and engineers can achieve.  Talk about soft power.

This is important to remember as the agency’s 40-year-old Great Observatories program –that the Hubble Telescope is a part of –is under considerable threat.

The mission that was supposed to fly in the 2010s, the James Webb Space Telescope, is also way over budget, way behind schedule, and now described as a financial threat to other NASA missions. … Read more

Our Ever-Growing Menagerie of Exoplanets

While we have never seen an exoplanet with anything near this kind of detail, scientists and artists now do know enough to represent them with characteristics that are plausible, given what is known about them..  (NASA)

With so many exoplanets already detected, with the pace of discovery continuing to be so fast, and with efforts to find more distant worlds so constant and global,  it’s easy to become somewhat blase´ about new discoveries.  After so many “firsts,” and so many different kinds of planets found in very different ways, it certainly seems that some of the thrill may be gone.

Surely the detection of a clearly “Earth-like planet” would cause new excitement — one that is not only orbiting in the habitable zone of its host star but also has signs of a potentially nurturing atmosphere in a generally supportive cosmic neighborhood.

But while many an exoplanet has been described as somewhat “Earth-like” and potentially habitable, further observation has consistently reduced the possibility of the planets actually hosting some form of biology.  The technology and knowledge base needed to find distant life is surely advancing, but it may well still have a long way to go.

In just the last few days, however, a slew of discoveries have been reported that highlight the allure and science of our new Exoplanet Era.  They may not be blockbusters by themselves, but they are together part of an immense scientific exploration under way, one that is re-shaping our understanding of the cosmos and preparing us for bigger discoveries and insights to come.

 

Already 3,940 exoplanets have been identified (as of April 17) with an additional 3,504 candidates waiting to be confirmed or discarded.  this is but the start since it is widely held now that virtually every star out there has a planet, or planets, orbiting it.   That’s billions of billions of planets.  This image is a collection of NASA exoplanet renderings.

What I have in mind are these discoveries:

  • The first Earth-sized planet detected by NASA’s year-old orbiting telescope TESS (Transiting Exoplanet Survey Satellite.)  TESS is designed to find planets orbiting massive stars in our near neighborhood, and it has already made 10 confirmed discoveries.  But finding a small exoplanet — 85 percent the size of Earth — is a promising result for a mission designed to not only locate as many as 20,000 new exoplanets, but to find 500 to 1,000 the rough size of Earth or SuperEarth. 
Read more

The “Twin Study,” and What it Does and Does Not Say About The Health Hazards of Space Travel

Buzz Aldrin on the moon in 1969, photographed by first-on-the-moon astronaut Neil Armstrong (NASA)

 

When Buzz Aldrin became the second man to ever walk on the moon, his lunar escapades, along with those of Neil Armstrong,  were a cause of national and pretty much global joy, wonder and pride.   That the mission was hazardous was self-evident — from launch to the ad-lib and hair-raising landing on the moon, to return to Earth– but the nation and certainly the astronauts were more than ready to take the risk.

A half century later, Armstrong has passed (at 82 from complication of cardiac surgery)  but Aldrin is still writing books and proposing plans to reach Mars. Their time in space may well have changed their lives and views of the world, but it did not seem to affect their basic health.

But the two were in space for only eight days and so were not exposed to the long-term effects of solar radiation, microgravity and isolation that are now under intense study.  Because the next generation of astronauts who may be going to the moon and beyond will be going for much longer periods of time and so will face a wide range of potential problems that weren’t considered major issues in Apollo or even later days.

Much has been learned since Apollo, however, and some of it raises new risks and new problems.  And that’s why the just-released Twin Study of the health comparison of long-staying International Space Station astronaut Scott Kelly and his ground-based twin brother Mark Kelly has been eagerly awaited.

Now that we know somewhat better what to look for in terms of more subtle damage that can come from long stays in space, what are the dangers and how serious are they?

Identical twins, Scott and Mark Kelly, are the subjects of NASA’s Twins Study. Scott (left) spent a year in space while Mark (right) stayed on Earth as a control subject.  It was Scott Kelly’s idea to have he and his (former astronaut) brother serve as subjects of the extensive research into the effects of space travel on the human body. (NASA)

“Given that the majority of the biological and human health variables remained stable, or returned to baseline, after a 340-dayspace mission, these data suggest that human health can be mostly sustained over this duration of spaceflight,”  the study concludes.

Published in Science, the intensive study was led by Francine E.… Read more

A Significant Advance: Primitive Earth Life Survives an 18-Month Exposure to Mars-Like Conditions in Space

The European Space Agency’s BIOMEX array, outside the Russian Zvezda module of the ISS. (ESA)

The question of whether simple life can survive in space is hardly new, but it has lately taken on a new urgency.

It is not only a pressing scientific question — might life from Mars or another body have seeded life on Earth?  Might organisms similar to extreme Earth life survive Mars-like conditions? — but it is also has some very practical implications.  If humans are going to some day land and live on the moon or on Mars, they will need to grow food to survive.

So the question is pretty basic:  can Earth seeds or dormant life survive a long journey to deep space and can they then  grow in the protected but still extreme radiation, temperature, and vacuum  of deep space?

It was with these questions in mind that the European Space Agency funded a proposal from the German Institute of Planetary Research to send samples of a broad range of simple to more complex life to the International Space Station in 2014, and to expose the samples to extreme conditions outside the station.

Some of the findings have been reported earlier,  but last month the full results of the Biomex tests (Biology on Mars Experiment) were unveiled in the journal Astrobiology.

And the answer is that many, though certainly not all, of the the samples of snow and permafrost algae, cyanobacteria, archaea, fungi, biofilms, moss and lichens in the  did survive their 533 days of living dangerous in their dormant states.  When brought back to Earth and returned to normal conditions, they returned to active life.

“For the majority of the chosen organisms, it was the first and the longest time they ever were exposed to space and Mars-like conditions,” Jean-Pierre Paul de Vera, principal investigator of the effort, wrote to me.  And the results were promising.

 

For the BIOMEX experiment, on 18 August 2014, Russian cosmonauts Alexander Skvortsov and Oleg Artemyev placed several hundred samples in an experiment container on the exterior of the Zvezda’Russian ISS module. The containers, open to the surrounding space environment, held primitive terrestrial organisms such as mosses, lichens, fungi, bacteria, archaea and algae, as well as cell membranes and pigments.

 

A microbiologist and planetary researcher at the German Space Agency’s Institute of Planetary Research in Berlin, de Vera and his team went from Antarctica to the parched Atacama desert in Chile, from the high Alps to the steppe highlands of central Spain to find terrestrial life surviving in extreme conditions (extremophiles.)

The samples were then placed in regolith (soil, dust and other rocky materials) simulated to be as close as possible to what is found on Mars.Read more

Ancient Mars Water. Ever More of It, and Flowing Ever Longer on the Surface

A photo of a preserved river channel on Mars with color overlaid to show different elevations (blue is low, yellow is high).
(Courtesy of NASA/JPL/Univ. Arizona/Univ. Chicago)

 

Rather like a swollen river overflowing its banks, the story of water on Mars keeps on rising and spreading in quite unpredictable ways.

While the planet is now inarguable parched — though with lots of polar and subsurface ice and, perhaps, some seasonal surface trickles — data from the Curiosity rover, the Mars Reconnaissance Orbiter and other missions have proven quite reliably that the planet was once much wetter and warmer.  But how much wetter, and for how long,  remains of subject of hot debate.

On one side, Mars climate modelers have struggled to find mechanisms to keep the planet wetter and warmer for more than it’s earliest period — perhaps 500 million years.  Their projections flow from the seemingly established conclusion that Mars lost much of its atmosphere by 3.5 billion years ago, and without that protection warmer and wetter appear to be impossible.

But the morphology of the planet, the gorges, the fossil lakes, the riverbeds and deltas that are visible  because of 21st century technology and missions,  appears to tell a different and more wide-ranging story of Mars water.

 

Mudstone at the “Kimberley” formation on Mars taken by NASA’s Curiosity rover. The strata in the foreground dip towards the base of Mount Sharp, indicating the ancient depression that existed before the larger bulk of the mountain formed.
Credit:NASA/JPL-Caltech/MSSS

And now, in one of the most expansive interpretations of the Martian water story, University of Chicago planetary scientist and Mars expert Edwin Kite and colleagues report in a Science Advances paper that the planet not only once had many, many lakes and rivers, but that they were filled as part of a water cycle involving precipitation, rather than primarily through the sporadic melting of primordial ice as a result of incoming meteorites or other astrophysical events.

What’s more, they write, the rivers continued to sporadically flow well past the time when the Martian surface has been assumed to be dead dry.

The era when Mars has been most often described as going from wet-to-dry is around 3.5 billion years ago, but their interpretation of when precipitation-filled rivers stopped running is about 3 billion years ago.  In other words, Kite’s team now says the rivers ran — often quite actively — for more than one billion years.… Read more

A New and Revelatory Window Into Evolution on Earth

A Leanchoilia fossil from at the Qingjiang site in China. A very early arthropod  found with sharply defined appendages is an arthropod and  one of the prime examples of early Cambrian life (D Fu et al., Science 363:1338 (2019)

Virtually every definition of the word “life” includes the capability to undergo Darwinian evolution as a necessary characteristic.  This is true of life on Earth and of thinking about what would constitute life beyond Earth.  If it can’t change, the thinking goes, then it cannot be truly alive.

In addition, evolutionary selection and change occurs within the context of broad planetary systems — the chemical makeup of the atmosphere, the climactic conditions, the geochemistry and more.  If an environment is changing, then the lifeforms that can best adapt to the new conditions are the ones that will survive and prosper.

So evolution is very much part of the landscape that Many Worlds explores — the search for life beyond Earth and effort to understand how life emerged on Earth.  Evolution happens in the context of broad conditions on Earth (and perhaps elsewhere), and finding potential life elsewhere involves understanding the conditions on distant planets and determining if they are compatible with life.

This all came to mind as I read about the discovery of a remarkable collection of fossils alongside a river in China, fossils of soft-bodied creatures that lived a half billion years ago in the later phase of what is termed the the Cambrian explosion.  They are of being compared already with the iconic “Burgess Shale” fossil find in Canada of decades ago, and may well shed equally revelatory light on a crucial time in the evolution of life on Earth.

Artist rendering of Qingjiang life showing characteristics of different early Cambrian taxonomical groups.  More than 50 percent had never been identified before. (ZH Yao and DJ Fu)

The new discovery is reported in the journal Science in a paper authored by Dongjing Fu and a team largely from the Northwest University in Xi’an.  The paper reports on a zoo of Cambrian-era creatures, with more than half of them never identified before in the rock record.

The animals are soft-bodied — making it all the more remarkable that they were preserved — and some bear little resemblance to anything that followed.   Like the Burgess Shale fossils, the Qingjiang discovery is of an entire ecosystem that largely disappeared as more fit (and predatory) animals emerged.… Read more

How Creatures End Up Miles Below the Surface of Earth, and Maybe Mars Too

Poikilolaimus oxycercus is a microscopic nematode, or roundworm, found alive and well more than a mile below the surface in South Africa, where its ancestors had lived for hundreds or thousands of years. (Gaetan Borgonie)

 

When scientists speculate about possible life on Mars, they generally speak of microbial or other simple creatures living deep below the irradiated and desiccated surface.  While Mars long ago had a substantial period that was wetter and warmer when it also had a far more protective atmosphere,  the surface now is considered to be lethal.

But the suggestion that some potential early Martian life could have migrated into the more protected depths is often discussed as a plausible, if at this point untestable possibility.  In this scenario, some of that primitive subsurface life might even have survived the eons in their buried, and protected, environments.

This thinking has gotten some support in the past decade with the discovery of bacteria and nematodes (roundworms) found as far down as three miles below the surface of South Africa, in water dated as being many thousands or millions years old.  The lifeforms have been discovered by a team that has regularly gone down into the nation’s super-hot gold and platinum mines to search for life coming out of boreholes in the rock face of deep mine tunnels.

 

Borgonie setting up a water collector for a borehole at the Driefontein mine in the Witwatersrand Basin  of South Africa.  He said he stopped counting his journeys into the deep mines at 50, but that the number now is much higher. (Courtesy of Borgonie)

Now a  new paper describes not only the discovery of additional deep subsurface life, but also tries to explain how the distant ancestors of the worms and bacteria and algae might have gotten there. 

Their conclusion:  many were pulled down when fractures opened in the aftermath of earthquakes and other seismic events.  While many lifeforms were swept down, only a small percentage were able to adapt, evolve and thus survive.

The is how Gaetan Borgonie, lead author of the paper in Scientific Reports, explained it to me via email:

“After the discovery of multicellular animals in the deep subsurface up to 3.8 km (2.5 miles) in South Africa everyone was baffled and asked the question how did they get that deep? This question more or less haunted us for more than a decade as we were unable to get our head around it.Read more

MarCO And The Future of CubeSats

 

MarCO-B, one of the experimental Mars Cube One (MarCO) CubeSats, took this image of Mars from about 4,700 miles away during its flyby last November. MarCO-B had been sent to Mars with its twin, MarCO-A, to serve as communications relays for NASA’s InSight spacecraft as it landed. The image includes a portion of the CubeSat’s high-gain, X-band antenna on the right. (NASA/JPL-Caltech)

 

CubeSats are the anti-big ticket space missions.

They come as small as 4 inches squared and in units that size weigh about 3 pounds.  They currently carry cameras, high gain antennas, radios and other scientific equipment, and because of their weight and size they can easily hitch a ride on a rocket sending a traditional large payload into orbit.

More than 900 CubeSats have been launched since they began in being deployed early this century, but only two have left low-Earth orbit. 

Those two went to Mars last year along with the InSight lander (a deep geology mission) and despite some short-term but nerve-racking radio silence just before they were needed, they performed exactly as planned.

In the process they both heightened the profile and the desirability of CubeSats as a growing addition to space science and commerce. 

 

A rendering of MarCO on its way to Mars, with solar panel and flat-panel antenna unfurled.  The core of the nanosatellite is about the size of a briefcase. (NASA-JPL)

 

Called Mars Cube One or MarCO, the two that accompanied InSight were both a technological demonstration and an important operational component — serving as the communication link between the spacecraft and Earth for seven crucial minutes during InSight’s descent.

“We exceeded expectations,” said MarCO chief engineer Andrew Klesh of NASA’s Jet Propulsion Lab, speaking during a NASA Future In-Space Operations (FISO) webinar. 

“Getting into deep space like we did shows that this is only the beginning for CubeSat missions to explore the solar system.   They are a real addition to communications and they provide a new way to conduct science along the way.”

While they were launched on the rocket that sent InSight to Mars, they detached soon after liftoff and flew on their own power to the scheduled meeting place on Mars.

The MarCO CubeSats maintained contact with Earth for almost all of the 6 month journey to Mars and then performed as planned during the InSight descent and landing,  they lost touch with Earth only weeks after. Read more

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