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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The mystery of why life uses molecules with specific orientations has deepened with a NASA-funded discovery that RNA — a key molecule thought to have potentially held the instructions for life before DNA emerged — can favor making the building blocks of proteins in either the left-hand or the right-hand orientation. Resolving this mystery could provide clues to the origin of life. The findings appear in research recently published in Nature Communications.
Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes (catalysts that speed up or regulate chemical reactions). Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acid building blocks in a huge variety of arrangements to make millions of different proteins. Some amino acid molecules can be built in two ways, such that mirror-image versions exist, like your hands, and life uses the left-handed variety of these amino acids. Although life based on right-handed amino acids would presumably work fine, the two mirror images are rarely mixed in biology, a characteristic of life called homochirality. It is a mystery to scientists why life chose the left-handed variety over the right-handed one.
A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite.NASA DNA (deoxyribonucleic acid) is the molecule that holds the instructions for building and running a living organism. However, DNA is complex and specialized; it “subcontracts” the work of reading the instructions to RNA (ribonucleic acid) molecules and building proteins to ribosome molecules. DNA’s specialization and complexity lead scientists to think that something simpler should have preceded it billions of years ago during the early evolution of life. A leading candidate for this is RNA, which can both store genetic information and build proteins. The hypothesis that RNA may have preceded DNA is called the “RNA world” hypothesis.
If the RNA world proposition is correct, then perhaps something about RNA caused it to favor building left-handed proteins over right-handed ones. However, the new work did not support this idea, deepening the mystery of why life went with left-handed proteins.
The experiment tested RNA molecules that act like enzymes to build proteins, called ribozymes. “The experiment demonstrated that ribozymes can favor either left- or right-handed amino acids, indicating that RNA worlds, in general, would not necessarily have a strong bias for the form of amino acids we observe in biology now,” said Irene Chen, of the University of California, Los Angeles (UCLA) Samueli School of Engineering, corresponding author of the Nature Communications paper.
In the experiment, the researchers simulated what could have been early-Earth conditions of the RNA world. They incubated a solution containing ribozymes and amino acid precursors to see the relative percentages of the right-handed and left-handed amino acid, phenylalanine, that it would help produce. They tested 15 different ribozyme combinations and found that ribozymes can favor either left-handed or right-handed amino acids. This suggested that RNA did not initially have a predisposed chemical bias for one form of amino acids. This lack of preference challenges the notion that early life was predisposed to select left-handed-amino acids, which dominate in modern proteins.
“The findings suggest that life’s eventual homochirality might not be a result of chemical determinism but could have emerged through later evolutionary pressures,” said co-author Alberto Vázquez-Salazar, a UCLA postdoctoral scholar and member of Chen’s research group.
Earth’s prebiotic history lies beyond the oldest part of the fossil record, which has been erased by plate tectonics, the slow churning of Earth’s crust. During that time, the planet was likely bombarded by asteroids, which may have delivered some of life’s building blocks, such as amino acids. In parallel to chemical experiments, other origin-of-life researchers have been looking at molecular evidence from meteorites and asteroids.
“Understanding the chemical properties of life helps us know what to look for in our search for life across the solar system,” said co-author Jason Dworkin, senior scientist for astrobiology at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and director of Goddard’s Astrobiology Analytical Laboratory.
Dworkin is the project scientist on NASA’s OSIRIS-REx mission, which extracted samples from the asteroid Bennu and delivered them to Earth last year for further study.
“We are analyzing OSIRIS-REx samples for the chirality (handedness) of individual amino acids, and in the future, samples from Mars will also be tested in laboratories for evidence of life including ribozymes and proteins,” said Dworkin.
The research was supported by grants from NASA, the Simons Foundation Collaboration on the Origin of Life, and the National Science Foundation. Vázquez-Salazar acknowledges support through the NASA Postdoctoral Program, which is administered by Oak Ridge Associated Universities under contract with NASA.
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Last Updated Nov 21, 2024 EditorWilliam SteigerwaldContactNancy N. Jonesnancy.n.jones@nasa.govLocationGoddard Space Flight Center Related Terms
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By NASA
On Nov. 6, 2024, NASA Night brought cosmic excitement to the Toyota Center, where Johnson Space Center employees joined 16,208 fans who interacted with NASA as they watched the Houston Rockets claim victory over the San Antonio Spurs.
Energy soared as International Space Station Program Manager Dana Weigel stepped up to take the first shot.
International Space Station Program Manager Dana Weigel takes the first shot on Nov. 6, 2024, as the Houston Rockets go up against the San Antonio Spurs at Toyota Center.NASA/Helen Arase Vargas The ceremonial first shot also gave back to the community, with Rockets owner Tilman Fertitta donating $1,000 to the Clutch City Foundation to support underserved youth through education, sports, and disaster relief.
Throughout the game, Johnson employees kept the crowd engaged with NASA trivia, creating a “launch countdown” energy that had fans cheering. The arena lit up as Adam Savage narrated a video showcasing the International Space Station’s groundbreaking contributions to science. From unlocking discoveries impossible on Earth to testing critical technologies for our return to the Moon, the orbiting laboratory plays a vital role in advancing medical and social breakthroughs that enhance life on our planet.
The Artemis II crew also appeared on the jumbotron, reminding everyone of NASA’s mission to establish a long-term presence on the Moon for scientific discovery, economic benefits, and to inspire a new generation of explorers.
Dana Weigel, center, shows off a Rockets jersey on the court with Rockets mascot Clutch, left, and NASA mascot Cosmo.NASA/Helen Arase Vargas In the Sky Court area of the stadium concourse, Johnson volunteers held “mission control” with an interactive exhibit that drew fans in like a gravitational pull. From exploring a Space Launch System model and handling a spacesuit helmet and glove to touching a 3.4-billion-year-old Moon rock collected during Apollo 17, NASA’s booth offered attendees a glimpse into space exploration.
Visitors had the chance to ask questions and bring home mission pins, stickers, and hands-on activities, provided by the International Space Station Program and the Artemis campaign. Seventy-five “Lucky Row” fans also received bags filled with NASA outreach materials, courtesy of the Johnson Public Engagement team.
NASA’s Johnson Space Center volunteers connect with fans at the game through an interactive exhibit.NASA The Orion Flight Simulator, with its realistic switches and displays, provided an immersive experience that allowed fans to dock the Orion spacecraft to humanity’s first lunar space station, Gateway.
More than 600 fans eagerly lined up to experience NASA’s mobile exhibit trailer in the Toyota Center parking lot—drawing lines as long as those at the box office.
Fans engage with the Orion Flight Simulator at NASA’s booth. NASA/Helen Arase Vargas Fans also tested their skills with a crew assembly activity focused on science, technology, engineering, and mathematics, simulating the challenges astronauts face in orbit. NASA’s inflatable mascot, Cosmo, joined the action on the court, posing for photos and adding galactic fun to events like the T-shirt giveaway.
The Houston Rockets mascot Clutch and NASA mascot Cosmo team up on the court at Toyota Center in Houston.NASA/Helen Arase Vargas NASA’s presence brought together the excitement of sports with the wonder of space exploration, inspiring fans to keep shooting for the stars.
View more images from the event below.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Use your mouse to explore this 360-degree view of Gediz Vallis channel, a region of Mars that NASA’s Curiosity rover surveyed before heading west to new adventures. NASA/JPL-Caltech/MSSS The rover captured a 360-degree panorama before leaving Gediz Vallis channel, a feature it’s been exploring for the past year.
NASA’s Curiosity rover is preparing for the next leg of its journey, a monthslong trek to a formation called the boxwork, a set of weblike patterns on Mars’ surface that stretches for miles. It will soon leave behind Gediz Vallis channel, an area wrapped in mystery. How the channel formed so late during a transition to a drier climate is one big question for the science team. Another mystery is the field of white sulfur stones the rover discovered over the summer.
Curiosity imaged the stones, along with features from inside the channel, in a 360-degree panorama before driving up to the western edge of the channel at the end of September.
The rover is searching for evidence that ancient Mars had the right ingredients to support microbial life, if any formed billions of years ago, when the Red Planet held lakes and rivers. Located in the foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain, Gediz Vallis channel may help tell a related story: what the area was like as water was disappearing on Mars. Although older layers on the mountain had already formed in a dry climate, the channel suggests that water occasionally coursed through the area as the climate was changing.
Scientists are still piecing together the processes that formed various features within the channel, including the debris mound nicknamed “Pinnacle Ridge,” visible in the new 360-degree panorama. It appears that rivers, wet debris flows, and dry avalanches all left their mark. The science team is now constructing a timeline of events from Curiosity’s observations.
NASA’s Curiosity captured this panorama using its Mastcam while heading west away from Gediz Vallis channel on Nov. 2, 2024, the 4,352nd Martian day, or sol, of the mission. The Mars rover’s tracks across the rocky terrain are visible at right.NASA/JPL-Caltech/MSSS The science team is also trying to answer some big questions about the sprawling field of sulfur stones. Images of the area from NASA’s Mars Reconnaissance Orbiter (MRO) showed what looked like an unremarkable patch of light-colored terrain. It turns out that the sulfur stones were too small for MRO’s High-Resolution Imaging Science Experiment (HiRISE) to see, and Curiosity’s team was intrigued to find them when the rover reached the patch. They were even more surprised after Curiosity rolled over one of the stones, crushing it to reveal yellow crystals inside.
Science instruments on the rover confirmed the stone was pure sulfur — something no mission has seen before on Mars. The team doesn’t have a ready explanation for why the sulfur formed there; on Earth, it’s associated with volcanoes and hot springs, and no evidence exists on Mount Sharp pointing to either of those causes.
“We looked at the sulfur field from every angle — from the top and the side — and looked for anything mixed with the sulfur that might give us clues as to how it formed. We’ve gathered a ton of data, and now we have a fun puzzle to solve,” said Curiosity’s project scientist Ashwin Vasavada at NASA’s Jet Propulsion Laboratory in Southern California.
NASA’s Curiosity Mars rover captured this last look at a field of bright white sulfur stones on Oct. 11, before leaving Gediz Vallis channel. The field was where the rover made the first discovery of pure sulfur on Mars. Scientists are still unsure exactly why theses rocks formed here. Spiderwebs on Mars
Curiosity, which has traveled about 20 miles (33 kilometers) since landing in 2012, is now driving along the western edge of Gediz Vallis channel, gathering a few more panoramas to document the region before making tracks to the boxwork.
Viewed by MRO, the boxwork looks like spiderwebs stretching across the surface. It’s believed to have formed when minerals carried by Mount Sharp’s last pulses of water settled into fractures in surface rock and then hardened. As portions of the rock eroded away, what remained were the minerals that had cemented themselves in the fractures, leaving the weblike boxwork.
On Earth, boxwork formations have been seen on cliffsides and in caves. But Mount Sharp’s boxwork structures stand apart from those both because they formed as water was disappearing from Mars and because they’re so extensive, spanning an area of 6 to 12 miles (10 to 20 kilometers).
Scientists think that ancient groundwater formed this weblike pattern of ridges, called boxwork, that were captured by NASA’s Mars Reconnaissance Orbiter on Dec. 10, 2006. The agency’s Curiosity rover will study ridges similar to these up close in 2025.NASA/JPL-Caltech/University of Arizona This weblike crystalline structure called boxwork is found in the ceiling of the Elk’s Room, part of Wind Cave National Park in South Dakota. NASA’s Curiosity rover is preparing for a journey to a boxwork formation that stretches for miles on Mars’ surface. “These ridges will include minerals that crystallized underground, where it would have been warmer, with salty liquid water flowing through,” said Kirsten Siebach of Rice University in Houston, a Curiosity scientist studying the region. “Early Earth microbes could have survived in a similar environment. That makes this an exciting place to explore.”
More About Curiosity
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington.
The University of Arizona, in Tucson, operates HiRISE, which was built by BAE Systems (formerly Ball Aerospace & Technologies Corp.), in Boulder, Colorado. JPL manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate in Washington.
For more about these missions:
science.nasa.gov/mission/msl-curiosity
science.nasa.gov/mission/mars-reconnaissance-orbiter
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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
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Last Updated Nov 18, 2024 Related Terms
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By NASA
Hubble Space Telescope Home Hubble Takes a Look at Tangled… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 2 min read
Hubble Takes a Look at Tangled Galaxies
This Hubble image features a pair of interacting spiral galaxies called MCG+05-31-045. ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)
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This NASA/ESA Hubble Space Telescope image depicts the cosmic tangle that is MCG+05-31-045, a pair of interacting galaxies located 390 million light-years away and a part of the Coma galaxy cluster.
The Coma Cluster is a particularly rich cluster that contains over a thousand known galaxies. Amateur astronomers can easily spot several of these in a backyard telescope (See Caldwell 35). Most of them are elliptical galaxies, and that’s typical of a dense galaxy cluster like the Coma Cluster: many elliptical galaxies form through close encounters between galaxies that stir them up, or even collisions that rip them apart. While the stars in interacting galaxies can stay together, their gas is twisted and compressed by gravitational forces and rapidly used up to form new stars. When the hot, massive, blue stars die, there is little gas left to form new generations of young stars to replace them. As spiral galaxies interact, gravity disrupts the regular orbits that produce their striking spiral arms. Whether through mergers or simple near misses, the result is a galaxy almost devoid of gas, with aging stars orbiting in uncoordinated circles: an elliptical galaxy.
It’s very likely that a similar fate will befall MCG+05-31-045. As the smaller spiral galaxy is torn up and integrated into the larger galaxy, many new stars will form, and the hot, blue ones will quickly burn out, leaving cooler, redder stars behind in an elliptical galaxy, much like others in the Coma Cluster. But this process won’t be complete for many millions of years.
Explore more Coma Cluster images from Hubble.
Hubble Uncovers Thousands of Globular Star Clusters Scattered Among Galaxies Hubble’s Galaxies With Knots, Bursts Hubble Sees Near and Far Hubble Sees Plunging Galaxy Losing Its Gas Hubble Catches Galaxies Swarmed by Star Clusters Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Nov 14, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Hubble Space Telescope Spiral Galaxies Keep Exploring Discover More Topics From Hubble
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Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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