Scientists are preparing for our best shot yet to find alien life on exoplanets, which are worlds that orbit other stars. As the James Webb Space Telescope (JWST), a space observatory with unparalleled sensitivity, gears up to take its first observations, researchers are gaming out the potential identification of biosignatures, which are signs of life, on the exoplanets in JWST’s sights.

Now, a team led by Maggie Thompson, a graduate student in astronomy and astrophysics at UC Santa Cruz, has presented an updated guide to interpreting detections of methane gas on exoplanets, which can be produced by living and abiotic processes. 

“This is a super exciting time!” said Thomspon in an email. “JWST is going to revolutionize our understanding of exoplanets and will allow us to begin characterizing the atmospheres of rocky, potentially habitable worlds. I'm very excited to see what JWST discovers and what sorts of interesting targets it identifies that we will want to continue observing with future telescopes.” 

Thompson and her colleagues note that “methane is the only biosignature that the James Webb Space Telescope could readily detect in terrestrial atmospheres,” making it “imperative to understand methane biosignatures to contextualize these upcoming observations,” according to a study published Monday in Proceedings of the National Academy of Sciences. 

Scientists are already trying to find biosignatures in the atmospheres of exoplanets that could hint at the presence of life, such as oxygen, oxone, and carbon dioxide. However, the molecular properties of methane line up with the JWST’s sweet observational spot at near-infrared wavelengths, making it a particularly important compound in the search for extraterrestrial life.  

“The way we will observe methane, or any atmospheric gas, in an exoplanet's atmosphere with JWST is going to be through spectral observations in the infrared,” Thompson explained. “Methane's absorption features in the near-infrared, where JWST is most sensitive, are stronger than that of molecular oxygen (O2) and ozone (O3), making methane more easily detectable than oxygen.” 

“In addition, other studies have simulated JWST data, including a paper by co-author Joshua Krissansen-Totton in 2018, found that it will likely be possible to detect and constrain methane abundances but detecting oxygen would be much more challenging,” she added.

To anticipate the complexities of a methane detection on an alien world, Thompson and her colleagues assessed the broader contexts that could help distinguish between bonafide biosignatures and emissions from natural geological processes, such as volcanic eruptions. 

Methane is short-lived in atmospheres compared to other compounds, such as carbon dioxide, so detecting it would be an indication that there is a huge supply of the gas constantly rising into the skies of another planet. One of the keys to determining whether that supply stems from living creatures or geological processes is to look at the overall composition of the atmosphere, the study suggests. 

For instance, volcanic eruptions and tectonic processes belch out methane, but these abiotic events also emit gasses such as carbon dioxide and carbon monoxide. Since carbon monoxide is an easy gas for many lifeforms to consume here on Earth, the team suggests that a planet with carbon dioxide and methane in its atmosphere, but relatively little carbon monoxide, is more likely to host life.

“Although JWST alone will likely not be able to fully assess habitability, it may identify interesting targets, like a rocky exoplanet with abundant methane and carbon dioxide with little to no carbon monoxide, which would motivate observations with future telescopes to uncover the broader planetary context necessary to determine if the methane is being produced by life,” Thompson said.

In addition to using past and present Earth as an analogue for studying atmospheric methane, the team looked to Mars, which appears to produce whiffs of the gas, and Saturn’s moon Titan, a world awash in volatile elements, including liquid and gas versions of methane. Atmospheric methane on Mars and Titan is likely to be abiotic, making these worlds useful analogs of lifeless exoplanets that nonetheless produce a powerful biosignature. These examples can help scientists avoid false positives when looking for aliens in other star systems.   

“Mercury is another interesting analog because, although its small size and proximity to the Sun preclude it from having an atmosphere, its crust is enriched in graphite (a crystalline form of carbon) and it serves as an example of worlds with more reducing interiors where you could imagine magmatic outgassing (i.e. volcanic activity) causing a methane-rich atmosphere,” Thompson noted. 

“We investigated this possibility in our study and found that it is unlikely for planets with very reduced interiors like Mercury to magmatically outgas significant methane because most of the carbon will actually remain in the solid form as graphite,” she continued. “That being said, Mercury is still an interesting analog for rocky exoplanets that have very reduced interior compositions, and more work is needed to fully understand the atmospheres that could form abiotically via outgassing of such reduced interiors.”

The new study presents a revamped framework for assessing methane biosignatures on exoplanets, but much more research is needed to tease out all the many ambiguous forms that the gas is bound to take in the skies of other worlds. Interestingly, many revelations about distant worlds are likely to be solved by continuing to look at planets closer to home.

“There are a lot of avenues for future research based on this study,” Thompson said. “I'm particularly excited to further explore the possibility of exoplanets that are like Saturn's moon Titan that have large inventories of volatile species. If such planets exist at the outer edge of the habitable zone (so colder than Earth, but still potentially habitable), I'd like to determine if such planets could have atmospheres rich in methane due to abiotic sources.”

“I also think there is a lot of work to be done to understand the ability of chemical reactions between water and rock to generate abiotic methane under different planetary environments, which will require more laboratory experiments and theoretical modeling,” she concluded.

The Department of Energy (DOE) is launching a battery manufacturing program in West Virginia with a $5 million investment that could turn the rust belt into a lithium belt.

DOE Secretary Jennifer Granholm and a cohort of federal officials, including Secretary of the Interior Deb Haaland and Senator Joe Manchin traveled to Charleston, West Virginia last week to announce that it would begin a pilot training program in Appalachia, to create “good-paying union jobs” in a region that has since been left behind by a dying coal industry. The goal, the agency said in a press release after the visit, is to build out an independent national supply chain for batteries and minerals that will be essential to the renewable transition, and to “break U.S dependence on China.” 

“American leadership in the global battery supply chain will be based not only on our innovative edge, but also on our skilled workforce of engineers, designers, scientists, and production workers,” Granholm said in the statement. “We should be building the full supply chain here.” 

In a part of the country where former fossil fuel towns are pockmarked with empty storefronts and lined by abandoned oil and gas wells, the DOE is making bets that renewable energy could offer a new way out from economic tailspin. The plan expresses specifically an intent to target pilot programs in communities “where energy and automotive industries once held sway.” 

“This community is embracing new chances and opportunity in their own way,” Granholm told local broadcaster WSAZ on Friday. “Nobody is coming here to tell West Virginia what it should do because West Virginia is figuring it out and it’s really exciting.” 

The program is part of a broader endeavor by a federal Interagency Working Group on Coal and Power Plant Communities and Economic Revitalization that uses infrastructure dollars to build out jobs in 13 Appalachian states, from Mississippi to New York. Other actions taken by working group member agencies: the Department of the Interior announced funding for abandoned mine reclamation projects in West Virginia; the Environmental Protection Agency created two grants for job training and environmental cleanup in Huntington; and the Economic Development Administration announced a federal award for a former mining town in Kentucky. 

Though the pilot program is specifically earmarked for workforce development, fragments of the energy industry have recently committed time to exploring the feasibility of extracting lithium from parts of Appalachia. Though much of the lithium industry in the US is clustered in the west, particularly in Southern California, according to the US Geological Survey, one of 20 known lithium deposits in the US surrounds Charlotte, North Carolina. In November, the region became part of an environmental justice debate after local mineral developer Piedmont Lithium Inc. launched a bid to build four 500-foot deep pit lithium mines, which was met by split reaction from residents. 

“Plenty of folks in this rural pocket aren’t willing to go that far,” E&E News reporter Mike Soroghan wrote about the proposed mines in November. “They don’t want the persistent blasting, traffic, dust and environmental degradation that comes with pit mining. It’s the kind of opposition that has dogged fossil fuel projects in the past and isn’t going away just because the projects now support clean energy such as electric vehicles.”

In February, mineral extraction company American Resources announced it had discovered “meaningful concentrations” of lithium and cobalt in Central Appalachia. Lithium is also present in West Virginia coals, and can be extracted from tailings left behind by now-defunct coal plants.

Last April, the DOE announced it was plugging $19-million into research for that, too—a move that Granholm said in a press release at the time would put “the very same fossil fuel communities that have powered our nation for decades” at “the forefront of the clean energy economy. The move that led to the creation of a research consortium at Pennsylvania State University devoted to identifying stores of minerals that will be essential to the renewable transition across Appalachia. 

“We really don’t have a database or an assessment of what is out there and how much of our demand can be met with these secondary resources,” said Sarma Pisupati, professor of energy and mineral engineering at Penn State and director of the project told rural news outlet The Daily Yonder in July. “That’s what’s missing. This is very crucial for industry to have a strategy for developing these resources and making them commercially extractable and available.”

The area has also recently been the focus of other alternative energy proposals. Last month, a group of major fossil fuel companies announced a pact to build a hydrogen hub in Appalachia, a prospect that a number of local environmental groups said would only require and enable further oil and gas production. But the tone of last week’s announcement feels different to local environmental groups, like the Ohio River Valley Institute, who told Motherboard in an email that the announcement was “great news.” 

“Unlike some federal efforts, such as those to develop blue hydrogen and to introduce carbon capture in coal and gas-fired power generation, there is a strong economic rationale and a market for cobalt-free batteries,” Sean O’Leary, senior researcher at the Institute said. “That suggests the business and the jobs have a good chance of being viable for the long term. And the initiative helps West Virginia join the rest of the nation in benefitting from clean energy transition.” 

The U.S. West and Midwest could be facing grid failure this summer, according to a Summer Reliability Assessment by the North American Electric Reliability Corporation. 

In its seasonal reliability assessment for the summer of 2022, the nonprofit corporation, which sets regulatory standards for U.S. grid operators, warned that the Midcontinent Independent System Operator (MISO) is at “high” risk of its energy reserves falling short of its normal energy needs. MISO provides energy transmission for the Midwest, Arkansas, Mississippi and Louisiana. Texas and the western U.S., meanwhile, are at “elevated risk” of seeing grid shortages should its power needs peak beyond normal volumes, according to the report. 

Screengrab: NERC

The latter eventuality is most likely to be the result of drought conditions that Texas and the Western and Southern U.S. have grappled with for years, the report says. As for the West, hydro-powered generators rely upon dwindling water reserves, without which the region must instead import electricity to meet demand on hot evenings. 

“In the event of wide-area extreme heat event, all U.S. assessment areas in the Western Interconnection are at risk of energy emergencies,” the report says definitively, leading to “forced outages.”

In Texas and the South, extreme heat threatens to increase peak demand, forcing outages and other emergency procedures for load shedding, or cutting supply to reduce strain on the grid. This is what happened last summer, when the grid operator asked Texans to reduce their usage amid a June heat wave, just months after the February, 2021 freeze forced widespread blackouts. In hot conditions, grid shortages introduce a number of heat-related health risks to vulnerable communities, beyond the day-to-day discomfort of being asked to raise one’s thermostat to 78 degrees fahrenheit, as Texans were asked to do. 

In the Midwest, things are a bit more dire, and perhaps more certain: MISO is gearing up to have 2.3 percent less generation capacity this summer than it had last year, while its projections for peak demand have gone up by 1.7 percent in kind. Crucially, at the start of the summer, the operator is missing a key transmission line connecting the northern and southern segments of its coverage area to damage caused by a tornado last December.

That means the Midwest grid operator will likely need to shed load or import extra electricity to meet normal demand this summer—a fact that MISO itself has expressed awareness of, per an April report from Utility Dive. 

NERC’s summer projections also point to ongoing strain on the supply chain, a result of both COVID-19 labor gaps and Russia’s war in Ukraine, to explain likely forthcoming grid strain. A number of ongoing energy generation and transmission projects have been slowed by a lack of product availability, shipping delays and labor shortages, the report says. That’s on top of the cybersecurity threats that Russia and other actors could pose to electricity and critical infrastructure in the U.S., and the forthcoming late-summer wildfire season, which could affect transmission lines in regions where flames break out.

In tandem, these factors create a mosaic of risk for grid operators, whom the report authors encourage to prepare for strain. 

“It’s a sobering report,” John Moura, NERC director of reliability assessment and performance analysis told Utility Dive. “It’s clear the risks are spreading ... and the pace of our grid transformation is a bit out of sync with the underlying realities and the physics of the system.” 

Our solar system is relatively tranquil at this point in time, with planets that follow predictable orbits around the Sun, but these cosmic surroundings weren’t always so calm.

Scientists have long suspected that during the infancy of our solar system, tumultuous instabilities dramatically shifted the orbits of the gas giants—Jupiter, Saturn, Uranus, and Neptune—and may have even straight-up kicked a fifth mysterious planet out into the interstellar wilderness. However, the exact trigger and timing of this type of instability, which has also appears to have occurred in other star systems, has remained a matter of debate

Now, scientists led by Beibei Liu, a physicist at Zhejiang University in China, have proposed a new mechanism that can explain how these giants ended up in their distant orbits, and can even account for some of the puzzling features of the solar system’s innermost rocky worlds, such as Earth and Mars. 

A previous hypothesis, known as the Nice model after the French city where it originated, proposed that the orbital instabilities arose after the evaporation of the cloudy primordial disk that birthed our solar system. Now, Liu and his colleagues present results from 14,000 simulations that suggest this evaporating cloud was, itself, the driver of the turbulent effects that led to the familiar planetary configuration we live in today, according to a study published on Wednesday in Nature. 

Study co-authors Seth Jacobson, a planetary scientist at Michigan State University, and Sean Raymond, an astronomer at the Laboratoire d'Astrophysique de Bordeaux in France, first started developing this new explanation a few years ago.

“While the evidence for a giant planet instability in the solar system is clear, both Sean and I knew that there was mounting evidence that the instability must have taken place much earlier than originally hypothesized in the 2005 Nice model,” Jacobson said in an email. 

Jacobson pointed to two main paradigm shifts about the early solar system that laid the groundwork for the new study. First, evidence suggests that a glut of ancient impact craters on the Moon may have been caused by a longer period of bombardment, rather than a short-lived pulse of collisions, as previously believed. Second, the Nice model suggests the instability occurred after the formation of rocky planets like Mars and Earth, but new research implies that these inner worlds would have been much more disrupted by this event if that were the real timeline.

“These two realizations over the last 15-ish years provoked us to question whether a different giant instability triggered earlier in solar system history could explain many of the same phenomena as the original Nice model,” Jacobson explained. “Sean and I were then thinking about what could be an alternative trigger and Sean identified Beibei Liu's work on planet-disk interactions near the magnetospheric cavity as potentially worth examining more closely as an analog to what might have happened during disk photoevaporation.”

This evaporation was sparked some 4.6 billion years ago when the Sun began to shine for the first time, prompting its heat and energy to push the cloud of gas and dust further out into the solar system. This process occurred within ten million years of the solar system’s birth, when its rocky worlds were still cooking, and its outer gas giants were emerging in neat compact orbits within the same plane of the gassy disk, much closer to the Sun than they are today. 

But as the cloud of dust moved outward, its inner edge caught the gas giants in its tide, causing their orbits to go awry and get more spread out. Liu’s team modeled this process, which they call the “rebound effect” using differing numbers of gas giants, including an early solar system that had five giant worlds, instead of four. The simulations predicted that this extra planet was gravitationally ejected from our system by instabilities caused by the dispersal of the primordial gas disk. 

Some scientists have already proposed that the solar system contains a hidden planet in its outer reaches, a hypothetical ice giant known as Planet Nine. Jacobson noted that he has “always been partial to the Planet Nine hypothesis” because of these early instability models, and added that “passing nearby stars could perturb that ice giant onto a distant orbit, like that hypothesized for Planet Nine.”

In addition to reconstructing the position of the giant planets, the results may also explain how Mars ended up so much smaller than Earth. As the disk evaporated through the embryonic inner planets, it may have disrupted the red planet as it formed, leading to its reduced mass. 

Moreover, the new study has implications well beyond our solar system, as the team notes that almost all the star systems that are observed beyond Earth are similarly shaped by orbital instabilities. Jacobson pointed out that only about five percent of star systems are arranged in the kind of resonant compact structure predicted by models, revealing a gap between our expectations and real observations of outer space.

“Other works, most importantly those of Andre Izidoro [an astronomer at Rice University], have then shown that dynamical instabilities must have occurred in these systems to explain how they go from where theory predicts they should be to where they are observed,” Jacobson said. “It could be that in each system the dynamical instability was triggered by a different mechanism, but the rebound effect that we discovered in this paper is nearly universal and reasonably could have caused instability in the ~95% of planetary systems that we see it in.”

In this way, unlocking the enigmatic origins of our local solar neighborhood could help us understand distant alien worlds across our galaxy, the Milky Way.

Update: This article has been updated with comments from co-author Seth Jacobson.