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Comet P/Shoemaker-Levy 9 "Gang Of Four"
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By NASA
Explore This Section Exoplanets Home Exoplanets Overview Exoplanets Facts Types of Exoplanets Stars What is the Universe Search for Life The Big Questions Are We Alone? Can We Find Life? The Habitable Zone Why We Search Target Star Catalog Discoveries Discoveries Dashboard How We Find and Characterize Missions People Exoplanet Catalog Immersive The Exoplaneteers Exoplanet Travel Bureau 5 Ways to Find a Planet Strange New Worlds Universe of Monsters Galaxy of Horrors News Stories Blog Resources Get Involved Glossary Eyes on Exoplanets Exoplanet Watch More Multimedia ExEP This artist’s concept pictures the planets orbiting Barnard’s Star, as seen from close to the surface of one of them. Image credit: International Gemini Observatory/NOIRLab/NSF/AURA/P. Marenfeld The Discovery
Four rocky planets much smaller than Earth orbit Barnard’s Star, the next closest to ours after the three-star Alpha Centauri system. Barnard’s is the nearest single star.
Key Facts
Barnard’s Star, six light-years away, is notorious among astronomers for a history of false planet detections. But with the help of high-precision technology, the latest discovery — a family of four — appears to be solidly confirmed. The tiny size of the planets is also remarkable: Capturing evidence of small worlds at great distance is a tall order, even using state-of-the-art instruments and observational techniques.
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Watching for wobbles in the light from a star is one of the leading methods for detecting exoplanets — planets orbiting other stars. This “radial velocity” technique tracks subtle shifts in the spectrum of starlight caused by the gravity of a planet pulling its star back and forth as the planet orbits. But tiny planets pose a major challenge: the smaller the planet, the smaller the pull. These four are each between about a fifth and a third as massive as Earth. Stars also are known to jitter and quake, creating background “noise” that potentially could swamp the comparatively quiet signals from smaller, orbiting worlds.
Astronomers measure the back-and-forth shifting of starlight in meters per second; in this case the radial velocity signals from all four planets amount to faint whispers — from 0.2 to 0.5 meters per second (a person walks at about 1 meter per second). But the noise from stellar activity is nearly 10 times larger at roughly 2 meters per second.
How to separate planet signals from stellar noise? The astronomers made detailed mathematical models of Barnard’s Star’s quakes and jitters, allowing them to recognize and remove those signals from the data collected from the star.
The new paper confirming the four tiny worlds — labeled b, c, d, and e — relies on data from MAROON-X, an “extreme precision” radial velocity instrument attached to the Gemini Telescope on the Maunakea mountaintop in Hawaii. It confirms the detection of the “b” planet, made with previous data from ESPRESSO, a radial velocity instrument attached to the Very Large Telescope in Chile. And the new work reveals three new sibling planets in the same system.
Fun Facts
These planets orbit their red-dwarf star much too closely to be habitable. The closest planet’s “year” lasts a little more than two days; for the farthest planet, it’s is just shy of seven days. That likely makes them too hot to support life. Yet their detection bodes well in the search for life beyond Earth. Scientists say small, rocky planets like ours are probably the best places to look for evidence of life as we know it. But so far they’ve been the most difficult to detect and characterize. High-precision radial velocity measurements, combined with more sharply focused techniques for extracting data, could open new windows into habitable, potentially life-bearing worlds.
Barnard’s star was discovered in 1916 by Edward Emerson Barnard, a pioneering astrophotographer.
The Discoverers
An international team of scientists led by Ritvik Basant of the University of Chicago published their paper on the discovery, “Four Sub-Earth Planets Orbiting Barnard’s Star from MAROON-X and ESPRESSO,” in the science journal, “The Astrophysical Journal Letters,” in March 2025. The planets were entered into the NASA Exoplanet Archive on March 13, 2025.
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Last Updated Apr 01, 2025 Related Terms
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By NASA
Curiosity Navigation Curiosity Home Mission Overview Where is Curiosity? Mission Updates Science Overview Instruments Highlights Exploration Goals News and Features Multimedia Curiosity Raw Images Images Videos Audio Mosaics More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions 2 min read
Sols 4443-4444: Four Fours for February
NASA’s Mars rover Curiosity acquired this image from about 25 centimeters (about 10 inches) away from the polygonally-fractured bedrock target named “Coldwater Canyon.” Curiosity captured the image using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover’s robotic arm, on Feb. 2, 2025 — sol 4441, or Martian day 4,441 of the Mars Science Laboratory Mission — at 08:40:11 UTC. NASA/JPL-Caltech/MSSS Earth planning date: Monday, Feb. 3, 2025
Another successful weekend plan left us about 23 meters (about 75 feet) farther down our Mount Sharp Ascent Route (MSAR), with all our science data downlinked to Earth and the planet clocks aligned once more. We only have until 18:26 Pacific time to get this Monday’s plan uplinked (due to the Soliday over the weekend), and two full days of science to plan!
Our first sol science block starts at 12:06 local Gale Crater time, including a ChemCam long-distance RMI mosaic and a five-shot laser on bedrock. After ChemCam is done, Mastcam is planning 42 images, including ChemCam’s LIBS spots, some meteorite fragments, sand troughs between bedrock blocks, and interesting vein structures in our surrounding terrain. Navcam is planning to finish out that science block with a large dust devil survey. After our remote science wraps up, we’ve committed the hours between about 15:00 and 22:45 to our full contact science suite. Luckily, SRAP passed yet again and we took the opportunity to plan two targets — “San Rafael Hills” as our DRT target and “Allison Mine” as a potential meteorite target.
After a nice, long sleep our rover will wake up at 09:53 local Gale time and start another round of remote science to start the sol. This time ChemCam will shoot their laser at the potential meteorite and contact target Allison Mine, with Mastcam following up to document the spots. After one last 20-minute sweep of Texoli butte through Mastcam, it’s time to pack up and head back down the MSAR. Hopefully our drive goes well again and we’ll find ourselves about 36 meters (about 118 feet) away on Wednesday!
Written by Natalie Moore, Mission Operations Specialist at Malin Space Science Systems
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Last Updated Feb 06, 2025 Related Terms
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By NASA
NASA has selected multiple companies to expand the agency’s Near Space Network’s commercial direct-to-Earth capabilities services, which is a mission-critical communication capability that allows spacecraft to transmit data directly to ground stations on Earth.
The work will be awarded under new Near Space Network services contracts that are firm-fixed-price, indefinite-delivery/indefinite-quantity contracts. Project timelines span from February 2025 to September 2029, with an additional five-year option period that could extend a contract through Sept. 30, 2034. The cumulative maximum value of all Near Space Network Services contracts is $4.82 billion.
Some companies received multiple task orders for subcategories identified in their contracts. Awards are as follows:
Intuitive Machines of Houston will receive two task order awards on its contract for Subcategory 1.2 GEO to Cislunar Direct to Earth (DTE) Services and Subcategory 1.3 xCislunar DTE Services to support NASA’s Lunar Exploration Ground Segment, providing additional capacity to alleviate demand on the Deep Space Network and to meet the mission requirements for unique, highly elliptical orbits. The company also previously received a task order award for Subcategory 2.2 GEO to Cislunar Relay Services. Kongsberg Satellite Services of Tromsø, Norway, will receive two task order awards on its contract for Subcategory 1.1 Earth Proximity DTE and Subcategory 1.2 to support science missions in low Earth orbit and NASA’s Lunar Exploration Ground Segment, providing additional capacity to alleviate demand on the Deep Space Network. SSC Space U.S. Inc. of Horsham, Pennsylvania, will receive two task order awards on its contract for Subcategories 1.1 and 1.3 to support science missions in low Earth orbit and to meet the mission requirements for unique, highly elliptical orbits. Viasat, Inc. of Duluth, Georgia, will be awarded a task order on its contract for Subcategory 1.1 to support science missions in low Earth orbit. The Near Space Network’s direct-to-Earth capability supports many of NASA’s missions ranging from climate studies on Earth to research on celestial objects. It also will play a role in NASA’s Artemis campaign, which calls for long-term exploration of the Moon.
NASA’s goal is to provide users with communication and navigation services that are secure, reliable, and affordable, so that all NASA users receive the services required by their mission within their latency, accuracy, and availability requirements.
These awards demonstrate NASA’s ongoing commitment to fostering strong partnerships with the commercial space sector, which plays an essential role in delivering the communications infrastructure critical to the agency’s science and exploration missions.
As part of the agency’s SCaN (Space Communications and Navigation) Program, teams at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, will carry out the work of the Near Space Network. The Near Space Network provides missions out to 1.2 million miles (2 million kilometers) with communications and navigation services, enabling spacecraft to exchange critical data with mission operators on Earth. Using space relays in geosynchronous orbit and a global system of government and commercial direct-to-Earth antennas on Earth, the network brings down terabytes of data each day.
Learn more about NASA’s Near Space Network:
https://www.nasa.gov/near-space-network
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Joshua Finch
Headquarters, Washington
202-358-1100
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Jeremy Eggers
Goddard Space Flight Center, Greenbelt, Maryland
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jeremy.l.eggers@nasa.gov
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By NASA
Scientists find that cometary dust affects interpretation of spacecraft measurements, reopening the case for comets like 67P as potential sources of water for early Earth.
Researchers have found that water on Comet 67P/Churyumov–Gerasimenko has a similar molecular signature to the water in Earth’s oceans. Contradicting some recent results, this finding reopens the case that Jupiter-family comets like 67P could have helped deliver water to Earth.
Water was essential for life to form and flourish on Earth and it remains central for Earth life today. While some water likely existed in the gas and dust from which our planet materialized around 4.6 billion years ago, much of the water would have vaporized because Earth formed close to the Sun’s intense heat. How Earth ultimately became rich in liquid water has remained a source of debate for scientists.
Research has shown that some of Earth’s water originated through vapor vented from volcanoes; that vapor condensed and rained down on the oceans. But scientists have found evidence that a substantial portion of our oceans came from the ice and minerals on asteroids, and possibly comets, that crashed into Earth. A wave of comet and asteroid collisions with the solar system’s inner planets 4 billion years ago would have made this possible.
This image, taken by ESA’s Rosetta navigation camera, was taken from a about 53 miles from the center of Comet 67P/Churyumov-Gerasimenko on March 14, 2015. The image resolution is 24 feet per pixel and is cropped and processed to bring out the details of the comet’s activity. ESA/Rosetta/NAVCAM While the case connecting asteroid water to Earth’s is strong, the role of comets has puzzled scientists. Several measurements of Jupiter-family comets — which contain primitive material from the early solar system and are thought to have formed beyond the orbit of Saturn — showed a strong link between their water and Earth’s. This link was based on a key molecular signature scientists use to trace the origin of water across the solar system.
This signature is the ratio of deuterium (D) to regular hydrogen (H) in the water of any object, and it gives scientists clues about where that object formed. Deuterium is a rare, heavier type — or isotope — of hydrogen. When compared to Earth’s water, this hydrogen ratio in comets and asteroids can reveal whether there’s a connection.
Because water with deuterium is more likely to form in cold environments, there’s a higher concentration of the isotope on objects that formed far from the Sun, such as comets, than in objects that formed closer to the Sun, like asteroids.
Measurements within the last couple of decades of deuterium in the water vapor of several other Jupiter-family comets showed similar levels to Earth’s water.
“It was really starting to look like these comets played a major role in delivering water to Earth,” said Kathleen Mandt, planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Mandt led the research, published in Science Advances on Nov. 13, that revises the abundance of deuterium in 67P.
About Kathleen Mandt
But in 2014, ESA’s (European Space Agency) Rosetta mission to 67P challenged the idea that Jupiter-family comets helped fill Earth’s water reservoir. Scientists who analyzed Rosetta’s water measurements found the highest concentration of deuterium of any comet, and about three times more deuterium than there is in Earth’s oceans, which have about 1 deuterium atom for every 6,420 hydrogen atoms.
“It was a big surprise and it made us rethink everything,” Mandt said.
Mandt’s team decided to use an advanced statistical-computation technique to automate the laborious process of isolating deuterium-rich water in more than 16,000 Rosetta measurements. Rosetta made these measurements in the “coma” of gas and dust surrounding 67P. Mandt’s team, which included Rosetta scientists, was the first to analyze all of the European mission’s water measurements spanning the entire mission.
The researchers wanted to understand what physical processes caused the variability in the hydrogen isotope ratios measured at comets. Lab studies and comet observations showed that cometary dust could affect the readings of the hydrogen ratio that scientists detect in comet vapor, which could change our understanding of where comet water comes from and how it compares to Earth’s water.
What are comets made of? It’s one of the questions ESA’s Rosetta mission to comet 67P/Churyumov-Gerasimenko wanted to answer. “So I was just curious if we could find evidence for that happening at 67P,” Mandt said. “And this is just one of those very rare cases where you propose a hypothesis and actually find it happening.”
Indeed, Mandt’s team found a clear connection between deuterium measurements in the coma of 67P and the amount of dust around the Rosetta spacecraft, showing that the measurements taken near the spacecraft in some parts of the coma may not be representative of the composition of a comet’s body.
As a comet moves in its orbit closer to the Sun, its surface warms up, causing gas to release from the surface, including dust with bits of water ice on it. Water with deuterium sticks to dust grains more readily than regular water does, research suggests. When the ice on these dust grains is released into the coma, this effect could make the comet appear to have more deuterium than it has.
Mandt and her team reported that by the time dust gets to the outer part of the coma, at least 75 miles from the comet body, it is dried out. With the deuterium-rich water gone, a spacecraft can accurately measure the amount of deuterium coming from the comet body.
This finding, the paper authors say, has big implications not only for understanding comets’ role in delivering Earth’s water, but also for understanding comet observations that provide insight into the formation of the early solar system.
“This means there is a great opportunity to revisit our past observations and prepare for future ones so we can better account for the dust effects,” Mandt said.
By Lonnie Shekhtman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Dec 03, 2024 Editor Lonnie Shekhtman Contact Lonnie Shekhtman lonnie.shekhtman@nasa.gov Location Goddard Space Flight Center Related Terms
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By USH
Cryptids are mysterious creatures often tied to folklore, mythology, and urban legends. While their existence remains scientifically unverified, the lack of concrete evidence does not necessarily rule out the possibility that they might be real.
Take the Nightcrawler, for instance. According to Native American folklore, these eerie, thin, upright creatures with no arms have been part of legend for centuries. In 2011, several CCTV recordings captured footage of similar beings, walking silently through the night.
Nightcrawlers - screenshots taken from the 2011 videos.
Another example involves a strange, unidentified creature seen climbing the edge of a cliff near Iceland’s Dettifoss waterfall. Such sightings fuel the belief that cryptids may exist.
Images creature photographed climbing cliff near Iceland’s Dettifoss waterfall.
Now, new evidence points to something even more unsettling. Beneath New Jersey's Pine Barrens lies a vast network of caves emitting electrical energy—a phenomenon impossible to explain in sedimentary rock. Scientists discovered similar formations in West Virginia, Oklahoma, and the Congo Basin. Intriguingly, each site is associated with its own legendary cryptid:
The Jersey Devil (New Jersey) The Flatwoods Monster (West Virginia) The Adair Beast (Oklahoma) Mokele-mbembe (Congo Basin)
Even more bizarre, these underground grids align perfectly, forming a growing mathematical pattern. The tunnels seem to converge toward a central point, as though following an ancient design.
Government researchers uncovered one last, chilling detail: the electrical patterns aren’t random. They form precise, repeating sequences—far too organized to occur naturally.
Could these tunnels be evidence of a cryptid connection? Or is something even more mysterious lurking beneath the surface?
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