Astrobiology Archives - Page 2 of 18

Category: Astrobiology (page 2 of 18)

Where Might Plumes of Water Vapor Come From on Icy Moons?

This illustration depicts a plume of water vapor that could potentially be emitted from the icy surface of Jupiter’s moon Europa. New research sheds light on what plumes, if they do exist, could reveal about lakes that may be inside the moon’s crust. (NASA/ESA/K. Retherford/SWRI)

It’s been some years since Europa scientists agreed that the Jovian moon has a large global ocean beneath miles of ice. More recently, scientists have identified what they view as pockets of water surrounded by ice but much nearer the surface than the ocean below. And there has been research as well into what may be salty, slushy pocket of water further down in the ice covering.

With NASA’s mission to Europa scheduled to launch in about two years, modeling of these all potential collections of liquid water has picked up to prepare for the Europa Clipper arrival to come.

The latest research into what the subsurface lakes on Europa may look like and how they may behave comes in a recently published paper in Planetary Science Journal.

A key finding supports the idea that water could potentially erupt above the surface of Europa either as plumes of vapor or as cryovolcanic activity — flowing, slushy ice rather than molten lava.

Computer modeling in the paper goes further, showing that if there are eruptions on Europa, they likely come from shallow, wide lakes embedded in the ice and not from the global ocean far below.

“We demonstrated that plumes or cryolava flows could mean there are shallow liquid reservoirs below, which Europa Clipper would be able to detect,” said Elodie Lesage, Europa scientist at NASA’s Jet Propulsion Laboratory and lead author of the research.

“Our results give new insights into how deep the water might be that’s driving surface activity, including plumes. And the water should be shallow enough that it can be detected by multiple Europa Clipper instruments.”

A minimally processed version of this image was captured by JunoCam, the public engagement camera aboard NASA’s Juno spacecraft. It was taken during the mission’s close flyby earlier this fall, almost 950 miles above the moon’s surface. The raw image was processed by “citizen scientist” Navaneeth Krishnan to add enhanced color contrast that allow larger surface features to stand out more.

The question of whether or not Europa has plumes is not settled. While the plumes coming from Saturn’s moon Enceladus have been well studied and even had a spacecraft fly through one, Europa has only some fuzzy Hubble Space Telescope, Galileo mission and ground-based telescope images that suggest a plume.… Read more

The Juno Spacecraft Images Jupiter’s Moon Europa as it Speeds Past

September 30, 2022 / Marc Kaufman / 0 Comments

The first image from NASA’s Juno spacecraft as it passed close by Europa as part of its extended mission. (NASA)

For NASA to extend its space science missions well past their original lifetime in space has become such a commonplace that it is barely noticed.

The Curiosity rover was scheduled to last on Mars for two years but now it has been going for a decade — following the pace set by earlier, smaller Mars rovers. The Cassini mission to Saturn was extended seven years beyond it’s original end date and nobody expected that Voyager 1, launched in 1977, would still flying out into deep space and sending back data 45 years later.

The newest addition to this virtuous collection of over-achievers is the Juno spacecraft, which arrived at Jupiter in 2016. Its prime mission in and around Jupiter ended last year and then was extended until 2025, or beyond.

And now we have some new and intriguing images of Jupiter’s moon Europa thanks to Juno and its extension.

Traveling at a brisk 14.7 miles per second, Juno passed within 219 miles of the surface of the icy moon on Thursday and images from the flyby were released today (Friday.) That gave the spacecraft only a two-hour window to collect data and images, but scientists are excited.

“It’s very early in the process, but by all indications Juno’s flyby of Europa was a great success,” said Scott Bolton, Juno principal investigator from Southwest Research Institute in San Antonio, in a NASA release.

“This first picture is just a glimpse of the remarkable new science to come from Juno’s entire suite of instruments and sensors that acquired data as we skimmed over the moon’s icy crust.”

Candy Hansen, a Juno co-investigator who leads planning for the Juno camera at the Planetary Science Institute in Tucson, called the released images “stunning.”

“The science team will be comparing the full set of images obtained by Juno with images from previous missions, looking to see if Europa’s surface features have changed over the past two decades,” she said.

An image of Europa taken by the Galileo spacecraft as it passed the moon in 1998. (NASA/JPL-Caltech)

During the flyby, the mission collected what will be some of the highest-resolution images of the moon (0.6 miles per pixel) taken so far and obtained valuable data on Europa’s ice shell structure, interior, surface composition, and ionosphere, in addition to the moon’s interaction with Jupiter’s magnetosphere.… Read more

How Planetary Orbits, in Our Solar System and Beyond, Can Affect Habitability

September 22, 2022 / Marc Kaufman / 0 Comments

Varying degrees of orbital eccentricity around a central star. (NASA/JPL-Caltech)

As scientists work to understand what might make a distant planet habitable, one factor that is getting attention is the shape of the planet’s orbit, how “eccentric” it might be.

It might seem that a perfect circular orbit would be ideal for habitability because it would provide stability, but a new model suggests that it is not necessarily the case. The planet in question is our own and what the model shows is that if Jupiter’s orbit were to change in certain ways, our planet might become more fertile than it is.

The logic play out as follows:

When a planet has a perfectly circular orbit around its star, the distance between the star and the planet never changes and neither does the in-coming heat. But most planets — including our own — have eccentric orbits around their stars, making the orbits oval-shaped. When the planet gets closer to its star it receives more heat, affecting the climate.

Using multi-factored models based on data from the solar system as it is known today, University of California, Riverside (UCR) researchers created an alternative solar system. In this theoretical system, they found that if Jupiter’s orbit were to become more eccentric, it would in turn produce big changes in the shape of Earth’s orbit. Potentially for the better.

“If Jupiter’s position remained the same but the shape of its orbit changed, it could actually increase this planet’s habitability,” said Pam Vervoort, UCR Earth and planetary scientist and study lead author.

The paper upends two long-held scientific assumptions about our solar system, she said.

“Many are convinced that Earth is the epitome of a habitable planet and that any change in Jupiter’s orbit, being the massive planet it is, could only be bad for Earth,” Vervoort said in a release. “We show that both assumptions are wrong.”

Size comparison of Jupiter and Earth shows why any changes relating to the giant planet would have ripple effects. (NASA)

As she and colleagues report in the Astronomical Journal, if Jupiter pushed Earth’s orbit to become more eccentric based on its new gravitational pull, parts of the Earth would sometimes get closer to the sun. As a results, parts of the Earth’s surface that are now sub-freezing would get warmer, increasing temperatures in the habitable range.

While the Earth-Jupiter connection is a focus of the paper and forms a relationship that’s not hard to understand, the thrust of the paper is modeling how similar kinds of exoplanet orbits and solar system relationships can affect habitability and the potential for life to emerge and prosper.… Read more

The Virtual Planetary Lab and Its Search for What Makes an Exoplanet Habitable, or Even Inhabited

September 14, 2022 / Marc Kaufman / 0 Comments

As presented by the Virtual Planetary Laboratory, exoplanet habitability is a function of the interplay of processes between the planet, the planetary system, and host star. These interactions govern the planet’s evolutionary trajectory, and have a larger and more diverse impact on a planet’s habitability than its position in a habitable zone. (Meadows and Barnes)

For more than two decades now, the Virtual Planetary Laboratory (VPL) at the University of Washington in Seattle has been at the forefront of the crucial and ever-challenging effort to model how scientists can determine whether a particular exoplanet is capable of supporting life or perhaps even had life on it already.

To do this, VPL scientists have developed or combined models from many disciplines that characterize and predict a wide range of planetary, solar system and stellar attributes that could identify habitability, or could pretty conclusively say that a planet is not habitable.

These include the well known questions of whether water might be present and if so whether temperatures would allow it to be sometimes in a liquid state, but on to questions involving whether an atmosphere is present, what elements and compounds might be in the atmospheres, the possible orbital evolution of the planet, the composition of the host star and how it interacts with a particular orbiting planet and much, much more, as shown in the graphic above.

This is work that has played a significant role in advancing astrobiology — the search for life beyond Earth.

More specifically, the VPL approach played a considerable part in building a body of science that ultimately led the Astro2020 Decadal Study of the National Academy of Sciences to recommend last year that the NASA develop its first Flagship astrobiology project — a mission that will feature a huge space telescope able to study exoplanets for signs of biology in entirely new detail. That mission, approved but not really defined yet, is not expected to launch until the 2040s.

With that plan actually beginning to move forward, the 132 VPL affiliated researchers at 28 institutions find themselves at another more current-day inflection point: The long-awaited James Webb Space Telescope has begun to collect and send back what will be a massive and unprecedented set of spectra of chemicals from the atmospheres of distant planets.

The Virtual Planetary Laboratory has modeled the workings of exoplanets since 2001, looking for ways to predict planetary conditions based on a broad range of measurable factors.

A Detailed New Mapping of Where Mars Once Had Plentiful Water

September 8, 2022 / Marc Kaufman / 0 Comments

Measurements from the OMEGA instrument of European Space Agency’s Mars Express and NASA’s Mars Reconnaissance Orbiter’s CRISM spectrometer were used to map where formed-in-water minerals can found across Mars. This is an especially concentrated spot at Jezero Crater, where the Perseverance rover is located. (ESA)

NASA’s long-time motto for exploring Mars has been “Follow the water.” That has changed some in recent years, as the presence of long-ago H₂O has been confirmed in many locales around the planet. Moving on, the motto today is more “Follow the organics” — the carbon-based building blocks of life — in the search for habitable environments and maybe signs of ancient life.

But water remains crucial to any discussion of habitability on Mars, and so a new set of global water maps from the European Space Agency, ten years in the making, is both useful and intriguing.

Specifically, the map shows the locations and abundances of these aqueous minerals — rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts.

And the message that the maps deliver, said planetary scientist John Carter, is that these hydrated minerals are common across many parts of the planet.

Ten years ago, planetary scientists knew of around 1, 000 water-altered outcrops on Mars, he said. This made them interesting as geological oddities.

But the new map has reversed the situation, revealing hundreds of thousands of such areas in the oldest parts of the planet.

“This work has now established that when you are studying the ancient terrains in detail, not seeing these minerals is actually the oddity,” says Carter, an assistant professor at the Institut d’Astrophysique Spatiale (IAS) in France.

Global map of hydrated minerals on Mars. (ESA)

Now, Carter said in a release, the big question is whether the water was persistent or confined to shorter, more intense episodes. While not yet providing a definitive answer, the new results certainly give researchers a better tool for pursuing the answer.

“I think we have collectively oversimplified Mars,” says Carter, who was lead author in a paper published in the journal Icarus.

He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period — roughly 3.5 billion to 4 billion years ago — then as the water gradually dried up salts were produced across the planet.

The James Webb Space Telescope Begins Looking at Exoplanets

August 24, 2022 / Marc Kaufman / 0 Comments

Artist rendering of Gliese (GJ) 436 b is a Neptune-sized planet that orbits a red dwarf star. Red dwarfs are cooler, smaller, and less luminous than the Sun. The planet completes one full orbit around its parent star in just a little over 2 days. It is made, scientists say, of extremely hot ice. (NASA/JPL-Caltech/UCF)

The James Webb Space Telescope has begun the part of its mission to study the atmospheres of 70 exoplanets in ways, and at a depth, well beyond anything done so far.

The telescope is not likely to answer questions like whether there is life on distant planet — its infrared wavelengths will tell us about the presence of many chemicals in exoplanet atmospheres but little about the presence of the element most important to life on Earth, oxygen.

But it is nonetheless undertaking a broad study of many well-known exoplanets and is likely to produce many tantalizing results and suggest answers to central questions about exoplanets and their solar systems.

Many Worlds has earlier looked at the JWST “early release” program, under which groups are allocated user time on the telescope under the condition that they make their data public quickly. That way other teams can understand better how JWST works and what might be possible.

Another program gives time to scientists who worked on the JWST mission and on its many instruments. They are given guaranteed time as part of their work making JWST as innovative and capable as it is.

One of the scientist in this “guaranteed time observations program” is Thomas Greene, an astrophysicist at NASA Ames Research Center. The groups he leads have been given 215 hours of observing time for this first year (or more) of Cycle 1 of JWST due to his many contributions to the JWST mission as well as his history of accomplishments.

In a conversation with Greene, I got a good sense of what he hopes to find and his delight at the opportunity. After all, he said, he has worked on the JWST idea and then mission since 1997.

“We will be observing a diverse sample of exoplanets to understand more about them and their characteristics,” Greene said. “Our goal is to get a better understanding of how exoplanets are similar to and different from those in our solar system.”

And the JWST spectra will tell them about the chemistry, the composition and the thermal conditions on those exoplanets, leading to insights into how they formed, diversified and evolved into planets often so unlike our own.… Read more

Icy Moons, And Exploring The Secrets They Hold

August 18, 2022 / Marc Kaufman / 0 Comments

Voyager 2’s flew by the Uranian moon Miranda in 1986 and the spacecraft spent 17 minutes taking photos to make this high-resolution portrait. Miranda has three oval and trapezoid coronae, tectonic features whose origins remain debated. (NASA / JPL / Ted Stryk)

When it come to habitable environments in our solar system, there’s Earth, perhaps Mars billions of years ago and then a slew of ice-covered moons that are likely to have global oceans under their crusts. Many of you are familiar with Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) — which have either been explored by NASA or will be in the years ahead.

But there quite a few others icy moons that scientists find intriguing and just possibly habitable. There is Ganymede, the largest moon of Jupiter and larger than Mercury but only 40 percent as dense, strongly suggesting a vast supply of water inside rather than rock.

There’s Saturn’s moon Titan, which is known for its methane lakes and seas on the surface but which has a subterranean ocean as well. There is Callisto, the second largest moon of Jupiter and an subsurface-ocean candidates and even Pluto and Ceres, now called dwarf planets that show signs of having interior oceans.

And of increasing interest are several of the icy moons of Uranus, particularly Ariel and Miranda. Each has features consistent with a subsurface ocean and even geological activity. Although Uranus is a distant planet, well past Jupiter and Saturn and would take more than a decade to just get there, the possibility of a future Uranus mission is becoming increasingly real.

The National Academy of Sciences (NAS) Decadal Survey for planetary science rated a Uranus mission as the highest priority in the field, and just today (Aug. 18) NASA embraced the concept.

At a NASA Planetary Science Division town hall meeting, Director Lori Glaze said the agency was “very excited” about the Uranus mission recommendation from the National Academy and that she hoped and expected some studies could be funded and begun in fiscal 2024.

If a Uranus mission is fully embraced, it would be the first ever specifically to an ice giant system — exploring the planet and its moons. This heightened interest reflects the fact that many in the exoplanet field now hold that ice giant systems are the most common in the galaxy and that icy moons may well be common as well.… Read more

Despite Everything, American-Russian Relations on the International Space Station Appear To Be Solid

August 5, 2022 / Marc Kaufman / 0 Comments

Late last month, it appeared that Russian participation in the International Space Station would end in 2024 — or so seemed to say the head of the Russian space agency, Roscosmos Thirty years of unusual and successful cooperation would be coming to a close as the Ukraine war appeared to make longer-term commitments impossible, or undesirable for the Russian side.

But on a day when the Ukraine war raged for its 163rd day, when new Western sanctions were being put into place, when a Russian judge gave WNBA star Brittney Griner a provocative 9-year prison term for carrying small amounts of cannabis oil as she left Moscow, and just a short time after what seemed to be the Russian announcement of that 2024 departure, NASA officials held a commodious press conference with Roscosmos Executive Director for Human Space Programs Sergei Krikalev and others involved with the ISS.

Together they spoke yesterday (August 4) of expanding American-Russian cooperation on the mission and discounted talk of a 2024 Russian exit.

“We always talk of spaceflight as being team support,” said Kathy Lueders, NASA’s associate administrator of NASA’s Space Operations, which oversees the ISS. “And this news conference will exemplify how it is a team sport.”

She then discussed how and why a Russian cosmonaut would soon take a SpaceX flight to the ISS as part of a new program under which Russian cosmonauts and American astronauts can fly on each other’s ISS-and-homeward-bound spacecraft. The flight by veteran cosmonaut Anna Kikina will mark the first time a Russian has flown on an American spacecraft.

In the press conference, Krikalev then insisted that Russia had no intention of leaving the station in 2024 but rather would begin looking at the logistics of departing at that time — with an eye to leaving for their own planned space station in the years ahead.

“As far as the statement for 2024, perhaps something was lost in translation,” he said. “The statement actually said Russia will not pull out until after 2024. That may be in 2025, 2028 or 2030.” He said the timetable “will depend on the technical condition of the station.”

In the good-natured spirit of the press conference, Krikalev said that he was “happy to see so many faces I’ve known for many years.”

Reports From Inside the Sun’s Corona

July 11, 2022 / Marc Kaufman / 1 Comment

This movie is built from images taken over 10 days during the full perihelion encounter when the spacecraft was nearing the Sun’s corona. The perihelion is a brief moment during the encounter time, when the spacecraft is at its closest point to the Sun. The movie is from orbit 10 and dates and distances are on the frames, and changing locations of planets are in red. (AHL/JHU; NASA)
To borrow from singer Paul Simon, these are definitely days of miracles and wonders — at least when it comes to exploring and understanding our Sun.

The Parker Solar Probe has been swinging further and further into the Sun’s corona, having just finished its 12th of 24 descents into a world of super-heated matter (plasma) where no human creation has ever gone.

The probe has dipped as close as 5.3 million miles from the surface of the sun — Mercury is 32 million miles from that solar surface — and is flying through the solar wind, through streamers (rays of magnetized solar material) and even at times through coronal mass ejections, those huge eruptions of magnetized plasma flying at speeds up to nearly 2,000 miles per second.

This is all a goldmine for solar scientists, an opportunity to study our star — and by extension all stars — up close and to learn much more about how it works.

At a four-day conference at the Johns Hopkins University Applied Physics Lab late last month, scores of scientists described the results of their early observations and analyses of the measurements and images coming from the Parker Probe via its The Wide-Field Imager (WISPR) and instruments that measure energy and magnetic flows. The results have often surprising and, as some scientists said, “thrilling.”

“Parker Solar Probe was developed to answer some of the biggest puzzles, biggest questions about our Sun,” said Nour Raouafi, project scientist for the Parker Solar Probe.

“We have learned so much that we believe we are getting close to finding some important answers. And we think the answers will be quite big for our field, and for science.”

The Parker Solar Probe had observed many switchbacks in the corona— traveling disturbances in the solar wind that cause the magnetic field to bend back on itself. They are an as-yet unexplained phenomenon that might help scientists uncover more information about how the solar wind is accelerated from the Sun. (NASA’s Goddard Space Flight Center/Conceptual Image Lab/Adriana Manrique Gutierrez)

Among the many unexpected solar features and forces detected by the Parker Probe is the widespread presence of switchbacks, rapid flips of the Sun’s magnetic field moving away from the Sun. … Read more

Mars Was Once Wetter and Warmer And It Had Life-Essential Organic Carbon. Was There Enough for Life to Emerge?

July 6, 2022 / Marc Kaufman / 0 Comments

Yellowknife Bay in Gale Crater, Mars, was extensively studied by the Curiousity rover in 2011-12 and was declared to have been “habitable” long ago. But the amount of life-essential organic carbon at the site appeared to be low, and now has been measured in detail. (NASA)

In the early days of the Curiosity mission on Mars, scientists were excited by what they found in what was once a mud-flat they called Yellowknife Bay. After months of drilling and testing, the mission team concluded that the site once had the roughly neutral water, an array of chemicals that could support metabolism and the organic carbon compounds needed for life. So Yellowknife Bay and the surrounding Gale Crater were deemed to have once been “habitable.”

The finding of organic carbon was a major step forward because it is essential as a building block for the emergence of life as we know it. The readings were clear that the organic carbon was present, but it has taken a decade to produce the first measurement of how much of the precious organic carbon was present.

The results, published late last month in the Proceedings of the National Academy of Sciences, show higher organic carbon levels than in some “low-life” environments on Earth. But those levels are still quite reduced and point to an unwelcoming Mars even in an area declared to be habitable billions of years ago when Mars was wetter and warmer.

“Total organic carbon is one of several measurements that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology,” said Jennifer Stern of NASA’s Goddard Space Flight Center.

“We found at least 200 to 273 parts per million of organic carbon. This is comparable to or even more than the amount found in rocks in very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than has been detected in Mars meteorites.”

The Atacama is one of the driest places on Earth, but it does support some life — bacteria under the surface of the desert and even some desert flowers in areas that experience fog. Not surprisingly, NASA and other scientists often use the Atacama when they study conditions on ancient Mars.

The Atacama desert in Chile is one of the driest places on Earth and is often studied as a Mars analog. (Shudderstock)

This carbon data has been a long time coming.

Category: Astrobiology (page 2 of 18)

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