Tag Archives: rocky

New Catalog of Rocky Exoplanets in the Habitable Zone Revealed by Astronomers

Posted on by
Reply

Utilizing data from ESA’s Gaia mission and NASA’s Exoplanet Archive, astronomers at Cornell University have discovered 45 rocky exoplanets in the habitable zone and 24 within the more specific 3D habitable zone. This groundbreaking research aids scientists in their quest for extraterrestrial life.

Artist’s impression of a planetary system around a star slightly hotter than the Sun. Image credit: Gillis Rowley.

“With over 6,000 known exoplanets from successful ground and space investigations, the research landscape has evolved significantly,” said Professor Lisa Kaltenegger of Cornell University and colleagues.

The expanding catalog of exoplanets enables astronomers to compile a targeted list for examining the boundaries of the habitable zone empirically.

This study reveals the identification of 45 rocky worlds that could potentially support life in the habitable zone, with an additional 24 in the narrower 3D habitable zone, suggesting a more cautious view on the heat a planet can endure.

Highlighted exoplanets include notable names such as Proxima Centauri b, Trappist 1f, and Kepler 186f, alongside lesser-known entities like TOI-715b.

Noteworthy planets include TRAPPIST-1d, e, f, g located 40 light-years from Earth, and LHS 1140 b, which is 48 light-years away. The possibility of liquid water on these planets hinges on their capacity to retain atmospheres.

Planets that receive light similar to that of Earth from the Sun are among the transiting candidates TRAPPIST 1e, TOI-715b, Kepler 1652b, Kepler 442b, and Kepler 1544b, as well as the star-wobble planets Proxima Centauri b, Gliese 1061d, Gliese 1002b, and Wolf 1069b.

The researchers also anticipate that planets on the edge of the habitable zone might clarify the limits of habitability and validate current scientific theories.

“Though the habitable zone concept has evolved since the 1970s, new observations are critical for determining whether adaptations are necessary,” stated Professor Kaltenegger.

Diagram displaying the boundaries of habitable zones across various star types, including rocky exoplanets. Image credit: Gillis Lowry / Pablo Carlos Budassi.

Moreover, exoplanets with unique elliptical orbits can monitor how variations in heat affect habitability, providing insights into whether a planet must remain in the habitable zone to sustain life.

Transiting planets useful for assessing habitability at the inner edge include K2-239d, TOI-700e, K2-3d, along with the star-wobble planets Wolf 1061c and Gliese 1061c.

On the outer edges of the habitable zone, planets like TRAPPIST-1g, Kepler-441b, and Gliese 1002c will be critical to exploring colder environments.

“Determining the factors that enhance the likelihood of life is complex, but narrowing down the best targets for observation is an essential first step,” remarked Gillis Rowley, a graduate student at San Francisco State University.

The research team has categorized optimal planets for observational techniques to maximize the chances of detecting signs of life.

This curated list will direct astronomers in their investigations using advanced instruments like the NASA/ESA/CSA James Webb Space Telescope, the future Nancy Grace Roman Space Telescope, the Very Large Telescope, the Habitable World Observatory, and the proposed Large Interferometer for Exoplanets (LIFE) project.

“Observing these small exoplanets is crucial to understanding their atmospheres and refining theories about their habitable zones,” concluded Lowry.

The research team’s paper is published today in the Royal Astronomical Society Monthly Notices.

_____

Abigail Ball et al. 2026. Exploring the boundaries of the habitable zone: A catalog of rocky exoplanets in the habitable zone. MNRAS 547 (3): stag028; doi: 10.1093/mnras/stag028

Source: www.sci.news

CHEOPS Uncovers Rocky Exoplanet Challenging Traditional Formation Theories

Posted on by
Reply

The European Space Agency’s (ESA) pioneering ExOPlanet satellite, CHEOPS, has uncovered a remarkable four-planet system. Notably, the outermost planet is a small rocky world instead of a gas giant, challenging previous assumptions about planet formation. This intriguing configuration surrounding the nearby red dwarf star LHS 1903 indicates that the outermost planet may have formed significantly later than its counterparts, providing compelling evidence that planets can develop in gas-poor environments—conditions once deemed impossible.

Artist’s impression of the four-planet system around LHS 1903. Image courtesy of ESA/ATG Europe.

LHS 1903 is an M dwarf star located approximately 116.3 light-years away in the constellation Lynx.

This star, also referred to as TOI-1730 or G 107-55, is cooler and less luminous than our Sun.

The planet sequence around LHS 1903 begins with the rocky planet LHS 1903b, followed by two gaseous planets, LHS 1903c and LHS 1903d—a pattern that aligns with expectations.

However, astronomer Thomas Wilson from the University of Warwick, along with his team, discovered a surprising fourth planet on the system’s outer edge, which is rocky rather than gaseous.

“This creates an inside-out planetary arrangement: rock → gas → gas → rock,” said Dr. Wilson.

“Typically, rocky planets are expected to form close to their host star.”

Current scientific models suggest that planets closest to a star are often rocky, as stellar radiation can strip away gaseous atmospheres, leaving behind dense, solid cores.

In contrast, gas giants form in cooler regions where they can retain gas.

However, LHS 1903e seems to have lost its gaseous atmosphere or may never have had one.

“The mystery surrounding planet formation and evolution remains significant,” stated Dr. Maximilian Günther, CHEOPS project scientist and ESA astronomer.

“Discovering clues like this is precisely what CHEOPS aims to achieve.”

The research team explored various hypotheses about the unusual formation of this rocky planet.

For instance, could it have been impacted by a giant asteroid or other large object that stripped away its atmosphere?

Or was there a gravitational exchange in the configuration of the planets over time?

Through simulations and orbital calculations, researchers ruled these scenarios out.

Instead, they presented a more fascinating explanation: the planets may have formed sequentially rather than simultaneously.

“By the time this exoplanet formed, the system may have been void of the gases typically necessary for planet formation, yet here we find a small, rocky world defying all expectations,” Dr. Wilson added.

“This could be the first evidence of planets forming in so-called gas-deficient conditions.”

A study detailing this groundbreaking discovery has been published in the latest issue of Science.

_____

Thomas G. Wilson et al. Formation of gas-deficient planets in a four-planet system around the red dwarf star LHS 1903. Science published online on February 12, 2026. doi: 10.1126/science.adl2348

Source: www.sci.news

Tianwen-2: China’s Upcoming Missions to Two Rocky Bodies in the Solar System

Posted on by
Reply

Artist impressions of Earth’s semi-satellite Kamo`oalewa, designated as the initial target for the Tianwen-2 mission

Addy Graham/University of Arizona

China is making final preparations to launch a spacecraft aimed at exploring asteroids and comets, seeking to gain insights into these celestial bodies in our solar system.

The Tianwen-2 mission, orchestrated by the China National Space Agency (CNSA), plans to collect 100 grams of samples from the asteroid Chuan West and return them to Earth. Following the sample retrieval, the probe will utilize Earth’s gravity to propel itself towards the comet 311P/Panstarrs, which will be observed remotely.

The mission is set for launch from the Xichang Satellite Launch Center in Sichuan Province on May 29th. While NASA’s Osiris-Rex and JAXA’s Hayabusa missions have previously returned asteroid samples, this marks China’s inaugural asteroid mission, including the return of rock samples, and potentially the first mission aimed at a unique type of celestial body known as quasi-satellites.

Quasi-satellites, like Kamo`oalewa, do not orbit the Earth in a traditional manner; instead, they follow orbits around the Sun that are similar to Earth’s, creating an oval path relative to our planet. This intriguing scenario has led scientists to theorize that this may be a remnant lunar mass ejected by an asteroid impact millions of years ago.

In contrast, 311P/Panstarrs has an asteroid-like orbit, encircling the Sun within the asteroid belt between Mars and Jupiter, yet possesses a tail that gives it a comet-like appearance. This is believed to be composed of dust and debris shed from its nucleus.

The CNSA has previously indicated that 311P/Panstarrs is a “living fossil,” crucial for studying the early material composition, formation processes, and evolutionary history of the solar system. Tianwen-2 aims to enhance our understanding of both Kamo`oalewa and 311P/Panstarrs. However, the findings will not be available immediately, as the spacecraft is expected to reach 311P/Panstarrs by 2034, and the Kamo`oalewa samples are anticipated to return to Earth in the latter half of 2027.

It remains uncertain what extent the CNSA will share these findings. Leah-Nani Alconcel from the University of Birmingham, UK, mentions that the mission outline is known but lacks detailed information. One of the objectives may involve examining the differences between asteroids and comets to gain better insights into the diverse bodies of our solar system; however, specific details remain elusive.

In her previous experience with CNSA’s Double Star Satellite, Alconcel expressed concerns about the institution’s ability to provide substantial scientific data. She states, “It was incredibly challenging to negotiate with [the CNSA]. There is no public repository for this data.”

She describes the mission as ambitious, noting that Kamo`oalewa is in a rotating behavior. Navigation algorithms may require powerful computing resources to process images and sensor data sent back to Earth for calculations. “If we always opt for favorable and stable objects, we won’t gain much knowledge,” she warns. “There are numerous potential challenges ahead.”

The CNSA has not responded to requests for comment from New Scientist.

Topics:

Source: www.newscientist.com

Ancient forests hidden beneath the Rocky Mountains emerge as ice melts.

Posted on by
Reply

exposed white bark pine

Gregory Pederson

Melting ice in the Rocky Mountains has led to the discovery of a 5,900-year-old white bark pine forest. Scientists discovered more than 30 trees during an archaeological survey on Wyoming's Beartooth Plateau at about 3,100 meters above sea level, 180 meters above the current tree line.

This, he says, “allows us to learn about past conditions at high altitudes.'' Kathy Whitlock at Montana State University. Japanese white pine (Albicari pine) These plants needed to grow during warmer weather, she says, because they don't currently grow at this elevation.

To understand the history of the lost forests, Whitlock's team analyzed tree rings and used carbon dating to find out how old the forests were. They discovered that the tree lived between 5,950 and 5,440 years ago, a time when temperatures were steadily dropping.

Data from ice cores in places like Antarctica and Greenland suggest that these temperature drops were influenced by centuries of volcanic eruptions in the Northern Hemisphere. These produced enough aerial deposits to block sunlight and lower global temperatures until the environment became too cold for these high-altitude trees to survive.

Although the newly discovered tree was lying flat, it was in exceptional condition, indicating that it was rapidly preserved after death. Although there is no evidence of avalanche cover, there are traces consistent with the current expansion of the ice sheet.

Climate models suggest that more continuous volcanic eruptions occurred in Iceland 5,100 years ago, causing further temperature drops, team members say Joe McConnell at the Desert Research Institute in Nevada. These temperature drops led to the expansion of the ice belt, and “the fallen trees were buried in the ice and protected from the elements for the next 5,000 years,” he says.

Only in recent decades have temperatures warmed enough to free trees from their ice cellars. The current tree line is “likely to shift upward as temperatures rise in the coming decades,” Whitlock said.

“This discovery was made possible thanks to anthropogenic climate change. Rising temperatures are exposing areas that have been buried under ice for thousands of years,” she says. “While discoveries like this are scientifically interesting, they are also a sad reminder of how vulnerable alpine ecosystems are to climate change.”

“This study is a very elegant and careful use of a rare 'time capsule' that tells us not only about these mountain forests 6,000 years ago, but also about the climatic conditions that allowed them to exist.” '' he says. Kevin Antukaitis at the University of Arizona.

These trees are not the first such finds that researchers have unearthed from Rocky Mountain ice. Previous research had found “fragments of wooden shafts used for arrows and darts,” Whitlock said. One of the shafts has been radiocarbon dated to be more than 10,000 years old, “which tells us that people have been hunting in high-altitude environments for thousands of years,” she says.

topic:

Source: www.newscientist.com

New Method Discovered by Astronomers for Detecting Water Oceans and Alien Life on Rocky Exoplanets

Posted on by
Reply

Planets that are too close to their star (such as Venus) are too hot, and planets that are too far away (such as Mars) are too cold, but planets that are within the habitable zone have just the right temperature. Although great efforts have been made to identify planets in the theoretical habitable region of stars, until now there has been no way to know whether a planet really has liquid water. Now, astronomers from the University of Birmingham and the Massachusetts Institute of Technology have found that if an exoplanet’s atmosphere has less carbon dioxide than its neighbors, it may have liquid water on its surface. It was shown that it was suggested.

Artist’s impression of the super-Earth planet Ross 508b. Image credit: Sci.News.

Astronomers have detected more than 5,200 extrasolar worlds so far. Modern telescopes allow us to directly measure the distance from a planet to a star and the time it takes to complete one revolution.

These measurements help scientists infer whether a planet is within its habitable zone.

However, there was no way to directly confirm whether a planet was truly habitable, i.e. whether there was liquid water on its surface.

Throughout our solar system, astronomers can detect the presence of liquid oceans by observing glints, flashes of sunlight reflecting off liquid surfaces.

These glows, or specular reflections, have been observed, for example, on Saturn’s largest moon, Titan, and helped identify the moon’s large lakes.

However, detecting similar glows on distant planets is not possible with current technology.

But astronomer Julien de Witt of the Massachusetts Institute of Technology, astronomer Amaury Tryaud of the University of Birmingham and colleagues believe there is another habitable landform close to home that could be detected far away. I noticed something.

“Looking at what was happening to terrestrial planets in our own star system gave us an idea,” Tryaud said.

Venus, Earth, and Mars share similarities in that all three are rocky and live in relatively temperate regions relative to the Sun.

Earth is the only planet of the three that currently has liquid water. Researchers then noted another clear difference. That means there is significantly less carbon dioxide in Earth’s atmosphere.

“We think these planets formed in a similar way, and if we find a planet with less carbon than it does now, it must have gone somewhere else,” Tryaud said.

“The only process that can remove this much carbon from the atmosphere is a strong water cycle involving oceans of liquid water.”

In fact, Earth’s oceans have played a major and persistent role in absorbing carbon dioxide.

For hundreds of millions of years, the ocean has absorbed enormous amounts of carbon dioxide. This is about the same amount that remains in Venus’ atmosphere today.

This planetary effect has resulted in Earth’s atmosphere being significantly depleted in carbon dioxide compared to neighboring planets.

Dr. Frieder Klein, a researcher at the Woods Hole Oceanographic Institution, said: “On Earth, much of the carbon dioxide in the atmosphere is sequestered in seawater and solid rock over geological timescales; It has helped regulate climate and habitability for billions of years.” .

Astronomers reasoned that if a similar decrease in carbon dioxide was detected on a distant planet compared to a nearby planet, this would be a reliable signal of a liquid ocean and life on its surface. did.

“After an extensive review of the literature in many fields, from biology to chemistry to carbon sequestration related to climate change, we found that if carbon depletion is indeed detected, it is likely that liquid water and its effects are “We think this is likely a strong indication that this is a sign of life.” Dr. de Witt said.

In the study, the researchers developed a strategy to detect habitable planets by looking for traces of depleted carbon dioxide.

Such searches are ideal for “pea” systems, like our solar system, in which multiple terrestrial planets, all about the same size, orbit relatively close to each other.

The first step, the scientists suggest, is to confirm that a planet has an atmosphere by simply looking for the presence of carbon dioxide, which is expected to dominate the atmospheres of most planets.

“Carbon dioxide is a very strong absorber of infrared light and can be easily detected in the atmospheres of exoplanets,” Dr. de Witt said.

“The carbon dioxide signal could reveal the presence of an exoplanet’s atmosphere.”

Once astronomers determine that multiple planets in a system have atmospheres, they move on to measuring their carbon dioxide content to see if one planet has significantly less than the others.

If so, this planet is likely habitable, which means there is a large amount of liquid water on its surface.

However, habitable conditions do not necessarily mean that the planet is inhabited. To confirm whether life actually exists, the authors suggest that astronomers look for another feature in the planet’s atmosphere: ozone.

On Earth, plants and some microorganisms contribute to absorbing carbon dioxide, although to a lesser extent than the oceans. Nevertheless, as part of this process, living organisms release oxygen, which reacts with solar photons and turns into ozone. Ozone is a much easier molecule to detect than oxygen itself.

If a planet’s atmosphere shows signs of both ozone and carbon dioxide depletion, the planet may be habitable and inhabited by humans.

“If you see ozone, there’s a pretty good chance it’s related to carbon dioxide being consumed by life forms,” ​​says Tryaud.

“And if it’s life, it’s glorious life. It won’t be just a few bacteria. It’ll be a planetary-scale biomass that can process and interact with large amounts of carbon.”

The researchers believe NASA/ESA/CSA’s James Webb Space Telescope can measure carbon dioxide, and possibly ozone, in nearby multiplanetary systems like TRAPPIST-1, a seven-planet system orbiting a bright star. I’m guessing it is. Light years from Earth.

“TRAPPIST-1 is one of the few systems that can use the Web to study Earth’s atmosphere,” said Dr. de Witt.

“We now have a roadmap to finding habitable planets. If we all work together, we may make paradigm-changing discoveries within the next few years.”

of study It was published in the magazine natural astronomy.

_____

AHMJ triode other. Atmospheric carbon depletion as a tracer of water oceans and biomass in temperate terrestrial exoplanets. Nat Astron, published online on December 28, 2023. doi: 10.1038/s41550-023-02157-9

Source: www.sci.news