Members Can Post Anonymously On This Site
-
Similar Topics
-
By European Space Agency
Global warming is driving the rapid melting of the Greenland Ice Sheet, contributing to global sea level rise and disrupting weather patterns worldwide. Because of this, precise measurements of its changing shape are of critical importance for adapting to climate change.
Now, scientists have delivered the first measurements of the Greenland Ice Sheet’s changing shape using data from ESA's CryoSat and NASA's ICESat-2 ice missions.
View the full article
-
By NASA
The Fresh Eyes on Ice team receives the C. Peter Magrath exemplary project award from the Association of Public and Land-grant Universities. H. Buurman Congratulations to the Fresh Eyes on Ice project, which received a C. Peter Magrath exemplary project award from the Association of Public and Land-grant Universities! The award recognizes programs that demonstrate how colleges and universities have redesigned their learning, discovery, and engagement missions to deepen their partnerships and achieve broader impacts in their communities.
“Thank you to all of you for making this project what it is.” said Fresh Eyes on Ice project lead Research Professor Katie Spellman from the University of Alaska, Fairbanks. “We couldn’t do it without you.”
Fresh Eyes on Ice tracks changes in the timing and thickness of ice throughout Alaska and the circumpolar north. You can get involved by downloading the GLOBE Observer app and taking photos of ice conditions using the GLOBE Land Cover protocol.
Fresh Eyes on Ice is supported by the Navigating the New Arctic Program of the U.S. National Science Foundation and the NASA Citizen Science for Earth Systems Program.
Facebook logo @DoNASAScience @DoNASAScience Share
Details
Last Updated Dec 05, 2024 Related Terms
Citizen Science Earth Science Explore More
4 min read 2024 AGU Fall Meeting Hyperwall Schedule
Article
1 day ago
2 min read This Thanksgiving, We’re Grateful for NASA’s Volunteer Scientists!
Article
1 week ago
9 min read The Earth Observer Editor’s Corner: Fall 2024
Article
3 weeks ago
View the full article
-
By NASA
3 min read
Buckle Up: NASA-Funded Study Explores Turbulence in Molecular Clouds
This image shows the distribution of density in a simulation of a turbulent molecular cloud. NASA/E. Scannapieco et al (2024) On an airplane, motions of the air on both small and large scales contribute to turbulence, which may result in a bumpy flight. Turbulence on a much larger scale is important to how stars form in giant molecular clouds that permeate the Milky Way.
In a new NASA-funded study in the journal Science Advances, scientists created simulations to explore how turbulence interacts with the density of the cloud. Lumps, or pockets of density, are the places where new stars will be born. Our Sun, for example, formed 4.6 billion years ago in a lumpy portion of a cloud that collapsed.
“We know that the main process that determines when and how quickly stars are made is turbulence, because it gives rise to the structures that create stars,” said Evan Scannapieco, professor of astrophysics at Arizona State University and lead author of the study. “Our study uncovers how those structures are formed.”
Giant molecular clouds are full of random, turbulent motions, which are caused by gravity, stirring by the galactic arms and winds, jets, and explosions from young stars. This turbulence is so strong that it creates shocks that drive the density changes in the cloud.
The simulations used dots called tracer particles to traverse a molecular cloud and travel along with the material. As the particles travel, they record the density of the part of the cloud they encounter, building up a history of how pockets of density change over time. The researchers, who also included Liubin Pan from Sun Yat Sen University in China, Marcus Brüggen from the University of Hamburg in Germany, and Ed Buie II from Vassar College in Poughkeepsie, New York, simulated eight scenarios, each with a different set of realistic cloud properties.
This animation shows the distribution of density in a simulation of a turbulent molecular cloud. The colors represent density, with dark blue indicating the least dense regions and red indicating the densest regions. Credit: NASA/E. Scannapieco et al (2024) The team found that the speeding up and slowing down of shocks plays an essential role in the path of the particles. Shocks slow down as they go into high-density gas and speed up as they go into low-density gas. This is akin to how an ocean wave strengthens when it hits shallow water by the shore.
When a particle hits a shock, the area around it becomes more dense. But because shocks slow down in dense regions, once lumps become dense enough, the turbulent motions can’t make them any denser. These lumpiest high-density regions are where stars are most likely to form.
While other studies have explored molecular cloud density structures, this simulation allows scientists to see how those structures form over time. This informs scientists’ understanding of how and where stars are likely to be born.
“Now we can understand better why those structures look the way they do because we’re able to track their histories,” said Scannapieco.
This image shows part of a simulation of a molecular cloud. The colors represent density, with dark blue indicating the least dense regions and red indicating the densest regions. Tracer particles, represented by black dots, traverse the simulated cloud. By examining how they interact with shocks and pockets of density, scientists can better understand the structures in molecular clouds that lead to star formation. NASA/E. Scannapieco et al (2024) NASA’s James Webb Space Telescope is exploring the structure of molecular clouds. It is also exploring the chemistry of molecular clouds, which depends on the history of the gas modeled in the simulations. New measurements like these will inform our understanding of star formation.
View the full article
-
By European Space Agency
Video: 00:04:21 English Paxi explores wind
Learn about wind, what causes it and how and why we study it in the latest Paxi adventure
Spanish Paxi explora el viento
Aprende sobre el viento, qué lo provoca y cómo y por qué lo estudiamos en la última aventura de Paxi.
Romanian Paxi explorează vântul
Aflați despre vânt, ce îl provoacă și cum și de ce îl studiem în cea mai recentă aventură Paxi.
Portuguese Paxi explora o vento
Aprende sobre o vento, o que o provoca e como e porquê o estudamos na mais recente aventura Paxi.
Polish Paxi bada wiatr
Dowiedz się więcej o wietrze, jego przyczynach oraz o tym, jak i dlaczego go badamy w najnowszej przygodzie Paxi.
Norwegian Paxi utforsker vind
Lær mer om vind, hva som forårsaker den og hvordan og hvorfor vi studerer den i det nyeste Paxi-eventyret.
Italian Paxi osserva il vento
Imparate a conoscere il vento, le sue cause e come e perché lo studiamo nell'ultima avventura di Paxi.
Greek Ο Πάξι εξερευνά τον άνεμο
Μάθετε για τον άνεμο, τι τον προκαλεί και πώς και γιατί τον μελετάμε στην τελευταία περιπέτεια του Paxi.
German Paxi erforscht den Wind
Erfahren Sie im neuesten Paxi-Abenteuer mehr über Wind, seine Ursachen und wie und warum wir ihn untersuchen.
French Paxi te fait découvrir le vent
Découvrez le vent, ce qui le provoque et comment et pourquoi nous l'étudions dans la dernière aventure de Paxi.
Swedish Paxi utforskar vind
Lär dig mer om vind, vad som orsakar den och hur och varför vi studerar den i det senaste Paxi-äventyret.
Dutch Paxi onderzoekt wind
Leer meer over wind, wat het veroorzaakt en hoe en waarom we het bestuderen in het nieuwste Paxi-avontuur.
Danish Paxi udforsker vind
Lær om vind, hvad der forårsager den, og hvordan og hvorfor vi studerer den i det seneste Paxi-eventyr.
Czech Paxi zkoumá vítr
V nejnovějším dobrodružství Paxi se dozvíte, co vítr způsobuje, jak a proč ho studujeme.
Finnish Paxi tutkii tuulta
Tutustu tuuleen, sen syihin sekä siihen, miten ja miksi sitä tutkitaan uusimmassa Paxi-seikkailussa.
Estonian Paxi avastab tuult
Tutvu tuulega, selle põhjustega ning sellega, kuidas ja miks me seda uurime Paxi viimases seikluses.
View the full article
-
By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Researchers think meltwater beneath Martian ice could support microbial life.
The white material seen within this Martian gully is believed to be dusty water ice. Scientists believe this kind of ice could be an excellent place to look for microbial life on Mars today. This image, showing part of a region called Dao Vallis, was captured by NASA’s Mars Reconnaissance Orbiter in 2009.NASA/JPL-Caltech/University of Arizona These holes, captured on Alaska’s Matanuska Glacier in 2012, are formed by cryoconite — dust particles that melt into the ice over time, eventually forming small pockets of water below the glacier’s surface. Scientists believe similar pockets of water could form within dusty water ice on Mars.Kimberly Casey CC BY-NC-SA 4.0 While actual evidence for life on Mars has never been found, a new NASA study proposes microbes could find a potential home beneath frozen water on the planet’s surface.
Through computer modeling, the study’s authors have shown that the amount of sunlight that can shine through water ice would be enough for photosynthesis to occur in shallow pools of meltwater below the surface of that ice. Similar pools of water that form within ice on Earth have been found to teem with life, including algae, fungi, and microscopic cyanobacteria, all of which derive energy from photosynthesis.
“If we’re trying to find life anywhere in the universe today, Martian ice exposures are probably one of the most accessible places we should be looking,” said the paper’s lead author, Aditya Khuller of NASA’s Jet Propulsion Laboratory in Southern California.
Mars has two kinds of ice: frozen water and frozen carbon dioxide. For their paper, published in Nature Communications Earth & Environment, Khuller and colleagues looked at water ice, large amounts of which formed from snow mixed with dust that fell on the surface during a series of Martian ice ages in the past million years. That ancient snow has since solidified into ice, still peppered with specks of dust.
Although dust particles may obscure light in deeper layers of the ice, they are key to explaining how subsurface pools of water could form within ice when exposed to the Sun: Dark dust absorbs more sunlight than the surrounding ice, potentially causing the ice to warm up and melt up to a few feet below the surface.
The white edges along these gullies in Mars’ Terra Sirenum are believed to be dusty water ice. Scientists think meltwater could form beneath the surface of this kind of ice, providing a place for possible photosynthesis. This is an enhanced-color image; the blue color would not actually be perceptible to the human eye.NASA/JPL-Caltech/University of Arizona Mars scientists are divided about whether ice can actually melt when exposed to the Martian surface. That’s due to the planet’s thin, dry atmosphere, where water ice is believed to sublimate — turn directly into gas — the way dry ice does on Earth. But the atmospheric effects that make melting difficult on the Martian surface wouldn’t apply below the surface of a dusty snowpack or glacier.
Thriving Microcosms
On Earth, dust within ice can create what are called cryoconite holes — small cavities that form in ice when particles of windblown dust (called cryoconite) land there, absorb sunlight, and melt farther into the ice each summer. Eventually, as these dust particles travel farther from the Sun’s rays, they stop sinking, but they still generate enough warmth to create a pocket of meltwater around them. The pockets can nourish a thriving ecosystem for simple lifeforms..
“This is a common phenomenon on Earth,” said co-author Phil Christensen of Arizona State University in Tempe, referring to ice melting from within. “Dense snow and ice can melt from the inside out, letting in sunlight that warms it like a greenhouse, rather than melting from the top down.”
Christensen has studied ice on Mars for decades. He leads operations for a heat-sensitive camera called THEMIS (Thermal Emission Imaging System) aboard NASA’s 2001 Mars Odyssey orbiter. In past research, Christensen and Gary Clow of the University of Colorado Boulder used modeling to demonstrate how liquid water could form within dusty snowpack on the Red Planet. That work, in turn, provided a foundation for the new paper focused on whether photosynthesis could be possible on Mars.
In 2021, Christensen and Khuller co-authored a paper on the discovery of dusty water ice exposed within gullies on Mars, proposing that many Martian gullies form by erosion caused by the ice melting to form liquid water.
This new paper suggests that dusty ice lets in enough light for photosynthesis to occur as deep as 9 feet (3 meters) below the surface. In this scenario, the upper layers of ice prevent the shallow subsurface pools of water from evaporating while also providing protection from harmful radiation. That’s important, because unlike Earth, Mars lacks a protective magnetic field to shield it from both the Sun and radioactive cosmic ray particles zipping around space.
The study authors say the water ice that would be most likely to form subsurface pools would exist in Mars’ tropics, between 30 degrees and 60 degrees latitude, in both the northern and southern hemispheres.
Khuller next hopes to re-create some of Mars’ dusty ice in a lab to study it up close. Meanwhile, he and other scientists are beginning to map out the most likely spots on Mars to look for shallow meltwater — locations that could be scientific targets for possible human and robotic missions in the future.
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
2024-142
Share
Details
Last Updated Oct 17, 2024 Related Terms
Mars Astrobiology Jet Propulsion Laboratory Explore More
4 min read New Team to Assess NASA’s Mars Sample Return Architecture Proposals
NASA announced Wednesday a new strategy review team will assess potential architecture adjustments for the…
Article 20 hours ago 6 min read Christine Knudson Uses Earthly Experience to Study Martian Geology
Geologist Christine Knudson works with the Curiosity rover to explore Mars — from about 250…
Article 1 day ago 5 min read Snippet of Euclid Mission’s Cosmic Atlas Released by ESA
Article 2 days ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.