Newswise — High in a narrow, seawater-filled crevasse in the base of Antarctica’s largest ice shelf, cameras on the remotely operated Icefin underwater vehicle relayed a sudden change in scenery.
Walls of smooth, cloudy meteoric ice abruptly turned green and rougher in texture, transitioning to salty marine ice.
Nearly 1,900 feet above, near where the surface of the Ross Ice Shelf meets Kamb Ice Stream, a U.S.-New Zealand research team recognized the shift as evidence of “ice pumping” – a process never before directly observed in an ice shelf crevasse, important to its stability.
“We were looking at ice that had just melted less than 100 feet below, flowed up into the crevasse and then refrozen,” said Justin Lawrence, visiting scholar at the Cornell Center for Astrophysics and Planetary Science. “And then it just got weirder as we went higher up.”
The paper reports results from a 2019 field campaign to Kamb Ice Stream supported by Antarctica New Zealand and other New Zealand research agencies, led by Christina Hulbe, professor at the University of Otago, and colleagues. Through support from NASA’s Astrobiology Program, a research team led by Britney Schmidt, associate professor of astronomy and earth and atmospheric sciences at Cornell, was able to join the expedition and deploy Icefin. Schmidt’s Planetary Habitability and Technology Lab has been developing Icefin for nearly a decade, beginning at the Georgia Institute of Technology.
Combined with recently published investigations of the fast-changing Thwaites Glacier – explored the same season by a second Icefin vehicle – the research is expected to improve models of sea-level rise by providing the first high-resolution views of ice, ocean and sea floor interactions at contrasting glacier systems on the West Antarctic Ice Sheet.
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Thwaites, which is exposed to warm ocean currents, is one of the continent’s most unstable glaciers. Kamb Ice Stream, where the ocean is very cold, has been stagnant since the late 1800s. Kamb currently offsets some of the ice loss from western Antarctica, but if it reactivates could increase the region’s contribution to sea-level rise by 12%.
“Antarctica is a complex system and it’s important to understand both ends of the spectrum – systems already undergoing rapid change as well as those quieter systems where future change poses a risk,” Schmidt said. “Observing Kamb and Thwaites together helps us learn more.”
NASA funded Icefin’s development and the Kamb exploration to extend ocean exploration beyond Earth. Marine ice like that found in the crevasse may be an analog for conditions on Jupiter’s icy moon Europa, the target of NASA’s Europa Clipper orbital mission slated for launch in 2024. Later lander missions might one day search directly for microbial life in the ice.
Icefin carries a full complement of oceanographic instruments on a modular frame more than 12 feet long and less than 10 inches in diameter. It was lowered on a tether through a borehole the New Zealand team drilled through the ice shelf with hot water.
During three dives spanning more than three miles near the grounding zone where Kamb transitions to the floating Ross shelf, Icefin mapped five crevasses – ascending one – and the sea floor, while recording water conditions including temperature, pressure and salinity.
The team observed diverse ice features that provide valuable information about water mixing and melt rates. They included golf ball-like dimples, ripples, vertical runnels and the “weirder” formations near the top of the crevasse: globs of ice and finger-like protrusions resembling brinicles.
Ice pumping observed in the crevasse likely contributes to the relative stability of the Ross Ice Shelf – the world’s largest by area, the size of France – compared to Thwaites Glacier, the researchers said.
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“It’s a way these big ice shelves can protect and heal themselves,” said Peter Washam, a polar oceanographer on the Icefin science team and the paper’s second author. “A lot of the melting that happens deep near the grounding line, that water then refreezes and accretes onto the bottom of the ice as marine ice.”
On the sea floor, Icefin mapped parallel sets of ridges that the researchers believe are impressions left behind by ice shelf crevasses – and a record of 150 years of activity since the Kamb stream stagnated. As its grounding line retreated, the ice shelf thinned, causing the crevasses to lift away. The ice’s slow movement over time shifted the crevasses seaward of the ridges.
“We can look at those sea floor features and directly connect them to what we saw on the ice base,” said Lawrence, the paper’s lead author, now a program manager and planetary scientist at Honeybee Robotics. “We can, in a way, rewind the process.”
In addition to Lawrence, Washam and Schmidt, Cornell co-authors of the research are Senior Research Engineers Matthew Meister, who led the Icefin engineering team, and Andrew Mullen; Research Engineer Daniel Dichek; and Program Manager Enrica Quartini. Schmidt’s team also includes Research Engineer Frances Bryson, and at Georgia Tech, doctoral students Benjamin Hurwitz and Anthony Spears.
Also contributing were partners from New Zealand at the National Institute of Water and Atmospheric Research (NIWA); University of Auckland; University of Otago; and Victoria University of Wellington.
NASA supported the research through the Planetary Science and Technology from Analog Research program’s Project RISE UP (Ross Ice Shelf and Europa Underwater Probe), and the Future Investigators in NASA Earth and Space Science and Technology program. Additional support came from New Zealand’s Antarctic Science Platform, the U.S. Antarctic Program and Victoria University of Wellington’s Hot Water Drilling initiative.
As summer approaches, Arizonans are bracing for yet another season of intense heat and unpredictable weather. According to forecasts from NOAA, AccuWeather, and the Old Farmer’s Almanac, summer2025 is shaping up to include above-average temperatures, sporadic monsoon activity, and potential drought conditions.
Above-Average Heat ExpectedNOAA predicts that Arizona will experience higher-than-average temperatures, continuing the warming trend of recent years. Phoenix and other urban areas may see extended stretches of triple-digit heat, making heat safety a top priority for residents.###
Monsoon Outlook AccuWeather forecasts a slightly below-average monsoon season. While Arizona relies on these summer storms for essential rainfall, experts warn of fewer storms, with flash flooding still possible in localized areas. Homeowners should prepare for potential microbursts and dust storms, especially in July and August. ###
Drought Concerns PersistThe Old Farmer’s Almanac suggests that while some areas might see sporadic relief, drought conditions will likely persist across much of the state. Water conservation efforts remain crucial as reservoirs and aquifers continue to face stress.###
Practical Tips for Staying Safe.
Hydration and Cooling: Always carry water and plan outdoor activities during early morning or evening hours.2.
Monsoon Prep: Secure outdoor furniture and prepare an emergency kit for storm-related power outages.3.
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Conservation Efforts: Reduce water usage by fixing leaks, using drought-resistant landscaping, and being mindful of daily consumption.###
Looking AheadArizona’s summer 2025 will challenge both residents and visitors with its heat and sporadic weather patterns. Staying informed and proactive can make all the difference in navigating the season safely.What are your favorite ways to beat the Arizona heat? Share your tips in the comments below!
Let me help you enhance the article with proper attribution and related links. First, I’ll search for the NOAA website.
Let me help you enhance the article with proper attribution and related links:
What Will Summer 2025 Be Like in Arizona? Here’s What the Experts Predict
Originally published by AZ Central on May 12, 2025
STM Daily News is a vibrant news blog dedicated to sharing the brighter side of human experiences. Emphasizing positive, uplifting stories, the site focuses on delivering inspiring, informative, and well-researched content. With a commitment to accurate, fair, and responsible journalism, STM Daily News aims to foster a community of readers passionate about positive change and engaged in meaningful conversations. Join the movement and explore stories that celebrate the positive impacts shaping our world.
‘Extraordinary claims require extraordinary evidence’ − an astronomer explains how much evidence scientists need to claim discoveries like extraterrestrial life
The universe is filled with countless galaxies, stars and planets. Astronomers may find life one day, but they will need extraordinary proof.
ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi Chris Impey, University of Arizona
The detection of life beyond Earth would be one of the most profound discoveries in the history of science. The Milky Way galaxy alone hosts hundreds of millions of potentially habitable planets. Astronomers are using powerful space telescopes to look for molecular indicators of biology in the atmospheres of the most Earth-like of these planets.
But so far, no solid evidence of life has ever been found beyond the Earth. A paper published in April 2025 claimed to detect a signature of life in the atmosphere of the planet K2-18b. And while this discovery is intriguing, most astronomers – including the paper’s authors – aren’t ready to claim that it means extraterrestrial life exists. A detection of life would be a remarkable development.
The astronomer Carl Sagan used the phrase, “Extraordinary claims require extraordinary evidence,” in regard to searching for alien life. It conveys the idea that there should be a high bar for evidence to support a remarkable claim.
I’m an astronomer who has written a book about astrobiology. Over my career, I’ve seen some compelling scientific discoveries. But to reach this threshold of finding life beyond Earth, a result needs to fit several important criteria.
When is a result important and reliable?
There are three criteria for a scientific result to represent a true discovery and not be subject to uncertainty and doubt. How does the claim of life on K2-18b measure up?
First, the experiment needs to measure a meaningful and important quantity. Researchers observed K2-18b’s atmosphere with the James Webb Space Telescope and saw a spectral feature that they identified as dimethyl sulfide.
On Earth, dimethyl sulfide is associated with biology, in particular bacteria and plankton in the oceans. However, it can also arise by other means, so this single molecule is not conclusive proof of life.
Second, the detection needs to be strong. Every detector has some noise from the random motion of electrons. The signal should be strong enough to have a low probability of arising by chance from this noise.
The K2-18b detection has a significance of 3-sigma, which means it has a 0.3% probability of arising by chance.
That sounds low, but most scientists would consider that a weak detection. There are many molecules that could create a feature in the same spectral range.
The “gold standard” for scientific detection is 5-sigma, which means the probability of the finding happening by chance is less than 0.00006%. For example, physicists at CERN gathered data patiently for two years until they had a 5-sigma detection of the Higgs boson particle, leading to a Nobel Prize one year later in 2013.
The announcement of the discovery of the Higgs boson took decades from the time Peter Higgs first predicted the existence of the particle. Scientists, such as Joe Incandela shown here, waited until they’d reached that 5-sigma level to say, ‘I think we have it.’
Third, a result needs to be repeatable. Results are considered reliable when they’ve been repeated – ideally corroborated by other investigators or confirmed using a different instrument. For K2-18b, this might mean detecting other molecules that indicate biology, such as oxygen in the planet’s atmosphere. Without more and better data, most researchers are viewing the claim of life on K2-18b with skepticism.
Claims of life on Mars
In the past, some scientists have claimed to have found life much closer to home, on the planet Mars.
Over a century ago, retired Boston merchant turned astronomer Percival Lowell claimed that linear features he saw on the surface of Mars were canals, constructed by a dying civilization to transport water from the poles to the equator. Artificial waterways on Mars would certainly have been a major discovery, but this example failed the other two criteria: strong evidence and repeatability.
Lowell was misled by his visual observations, and he was engaging in wishful thinking. No other astronomers could confirm his findings.
Mars, as taken by the OSIRIS instrument on the ESA Rosetta spacecraft during its February 2007 flyby of the planet and adjusted to show color.ESA & MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA, CC BY-SA
In 1996, NASA held a press conference where a team of scientists presented evidence for biology in the Martian meteorite ALH 84001. Their evidence included an evocative image that seemed to show microfossils in the meteorite.
However, scientists have come up with explanations for the meteorite’s unusual features that do not involve biology. That extraordinary claim has dissipated.
More recently, astronomers detected low levels of methane in the atmosphere of Mars. Like dimethyl sulfide and oxygen, methane on Earth is made primarily – but not exclusively – by life. Different spacecraft and rovers on the Martian surface have returned conflicting results, where a detection with one spacecraft was not confirmed by another.
The low level and variability of methane on Mars is still a mystery. And in the absence of definitive evidence that this very low level of methane has a biological origin, nobody is claiming definitive evidence of life on Mars.
Claims of advanced civilizations
Detecting microbial life on Mars or an exoplanet would be dramatic, but the discovery of extraterrestrial civilizations would be truly spectacular.
The search for extraterrestrial intelligence, or SETI, has been underway for 75 years. No messages have ever been received, but in 1977 a radio telescope in Ohio detected a strong signal that lasted only for a minute.
This signal was so unusual that an astronomer working at the telescope wrote “Wow!” on the printout, giving the signal its name. Unfortunately, nothing like it has since been detected from that region of the sky, so the Wow! Signal fails the test of repeatability.
‘Oumuamua is the first object passing through the solar system that astronomers have identified as having interstellar origins.European Southern Observatory/M. Kornmesser
In 2017, a rocky, cigar-shaped object called ‘Oumuamua was the first known interstellar object to visit the solar system. ‘Oumuamua’s strange shape and trajectory led Harvard astronomer Avi Loeb to argue that it was an alien artifact. However, the object has already left the solar system, so there’s no chance for astronomers to observe it again. And some researchers have gathered evidence suggesting that it’s just a comet.
While many scientists think we aren’t alone, given the enormous amount of habitable real estate beyond Earth, no detection has cleared the threshold enunciated by Carl Sagan.
Claims about the universe
These same criteria apply to research about the entire universe. One particular concern in cosmology is the fact that, unlike the case of planets, there is only one universe to study.
A cautionary tale comes from attempts to show that the universe went through a period of extremely rapid expansion a fraction of a second after the Big Bang. Cosmologists call this event inflation, and it is invoked to explain why the universe is now smooth and flat.
In 2014, astronomers claimed to have found evidence for inflation in a subtle signal from microwaves left over after the Big Bang. Within a year, however, the team retracted the result because the signal had a mundane explanation: They had confused dust in our galaxy with a signature of inflation.
On the other hand, the discovery of the universe’s acceleration shows the success of the scientific method. In 1929, astronomer Edwin Hubble found that the universe was expanding. Then, in 1998, evidence emerged that this cosmic expansion is accelerating. Physicists were startled by this result.
Two research groups used supernovae to separately trace the expansion. In a friendly rivalry, they used different sets of supernovae but got the same result. Independent corroboration increased their confidence that the universe was accelerating. They called the force behind this accelerating expansion dark energy and received a Nobel Prize in 2011 for its discovery.
On scales large and small, astronomers try to set a high bar of evidence before claiming a discovery.Chris Impey, University Distinguished Professor of Astronomy, University of Arizona
This article is republished from The Conversation under a Creative Commons license. Read the original article.
In a dramatic turn of events that captured international attention, the Soviet-era spacecraft Kosmos 482 has completed its final descent after spending over five decades in Earth’s orbit. The spacecraft, which had been closely monitored due to its deteriorating orbit pattern, crashed into the Indian Ocean west of Jakarta at approximately 11:24 p.m. Phoenix time on May 9, 2025, ending weeks of speculation about its potential impact in Arizona.
The Historic Background Originally launched in 1972 as part of an ambitious mission to Venus, Kosmos 482 became a remnant of the Cold War space race after its mission failed. The approximately 3-foot-diameter spacecraft had been trapped in Earth’s orbit for 53 years, joining the growing collection of space debris that concerns modern astronomers and space agencies.
Arizona’s Emergency Response The potential threat to Arizona prompted a swift and coordinated response from local authorities. The Phoenix metropolitan area, initially identified as one of the possible impact zones, activated its emergency response protocols. This included:
Establishment of a temporary command center by the Arizona Department of Emergency Management
Enhanced monitoring systems at Phoenix Sky Harbor International Airport
Coordination between local, state, and federal agencies
Implementation of emergency communication channels for public updates
Local Infrastructure Impact Coincidentally, this event intersected with Phoenix Sky Harbor’s ongoing modernization project, which aims to improve passenger experiences and facility capabilities. The airport’s emergency response teams incorporated spacecraft monitoring into their existing protocols, demonstrating the facility’s adaptive capacity during potential aerospace emergencies.
“This situation, while ultimately resolving without incident in our region, showcased our emergency response capabilities and the importance of our ongoing infrastructure improvements,” stated a Phoenix Sky Harbor spokesperson. The modernization project, which was already underway, proved particularly relevant during this potential aerospace emergency.
Community Response Local residents and businesses in the Phoenix metropolitan area remained vigilant throughout the monitoring period. Emergency management officials maintained regular communications with the public, providing updates through various channels to ensure community awareness and preparedness.
Technical Analysis Space tracking organizations employed advanced monitoring systems to track Kosmos 482’s descent. The spacecraft, powered by systems similar to other Cold War-era satellites, provided valuable data for modern space debris tracking programs. Unlike modern spacecraft such as Voyager 1, which continues to operate using a radioisotope power system, Kosmos 482 had long since lost its operational capabilities.
Final Outcome The spacecraft’s ultimate crash site in the Indian Ocean brought relief to Arizona residents and officials. The incident concluded at approximately 2:24 a.m. EDT (11:24 p.m. Phoenix time), with no reported casualties or damage.
Looking Forward This event serves as a crucial reminder of the challenges posed by orbital debris and the importance of maintaining robust emergency response systems. It also highlights Phoenix’s growing role in aerospace monitoring and emergency management, particularly as the city continues to expand its aviation infrastructure.
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The incident has prompted discussions about improving space debris monitoring systems and international cooperation in managing potential aerospace threats, ensuring better preparation for similar events in the future.
STM Daily News is a vibrant news blog dedicated to sharing the brighter side of human experiences. Emphasizing positive, uplifting stories, the site focuses on delivering inspiring, informative, and well-researchedcontent. With a commitment to accurate, fair, and responsible journalism, STM Daily News aims to foster a community of readers passionate about positive change and engaged in meaningful conversations. Join the movement and explore stories that celebrate the positive impacts shaping our world.
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Chris Impey, University Distinguished Professor of Astronomy, University of Arizona
This article is republished from The Conversation under a Creative Commons license. Read the original article.
