When a star like the Sun dies, it puffs away its outer layers, leaving behind its glowing core. Without fusion to keep it heated, the white dwarf slowly cools down over billions of years. Astronomers have discovered that 6% of massive white dwarfs pause their cooling for up to 10 billion years, providing a stable habitable zone for any planets nearby. This gives life a long time to develop under extremely stable conditions.
https://arxiv.org/abs/2501.06613
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SETI researchers announced the results of the COSMIC Cluster, which searches existing radio telescope observations for any sign of a signal from an advanced civilization. As of September 2024, the system has analyzed over 950,000 unique sky positions, focusing on the 2.5-3.5 GHz frequency range to avoid radio interference. As you probably can guess, no unexplained signals were detected, but it sets limits on how powerful signals would need to be for detection.
https://arxiv.org/abs/2501.17997
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Quasars are the actively feeding supermassive black holes at the hearts of galaxies and can contain millions or even billions of times the mass of the Sun. It's believed they're the source of some of the highest energy cosmic rays detected. But there are also microquasars, where a star and black hole orbit one another. Material from the star accretes around the black hole, and the magnetic fields form jets that can also hurl cosmic rays with similar energies.
https://www.mpi-hd.mpg.de/mpi/en/public-relations/news/news-item/so-small-and-yet-so-powerful
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In 2016, the Breakthrough Starshot Initiative announced funding for projects that would help develop an interstellar mission using lightsails. This uses a powerful laser to accelerate a lightweight sail to more than 10% the speed of light. Now, researchers have built a test rig in the lab where they can fire lasers at tethered miniature lightsails to measure how much direct radiation pressure they can get from a laser beam.
https://www.caltech.edu/about/news/the-pressure-to-explore-caltech-researchers-take-first-experimental-steps-toward-lightsails-that-could-reach-distant-star-systems
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The Japanese lunar mission Hakuto-R turned its cameras back to Earth to capture an image of our home planet. The very center of the image is Point Nemo, the most remote place on Earth, 2,688 km from anywhere else on Earth. The image was taken by the Resilience rover, which is similar to the first Hakuto-R mission that crashed on the lunar surface in April 2023. The rover will scoop up samples of lunar regolith for study, and the lander has other science experiments.
https://x.com/ispace_inc/status/1884558826558607740
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At the largest scale, the Universe consists of a vast network of interconnected filamentary structures surrounding huge empty voids. This is the "cosmic web." With hundreds of hours of telescope time, astronomers have created the highest resolution image ever taken of a single cosmic filament in the web that connects to actively forming galaxies, at a time when the Universe was only 2 billion years old. They could then match this with simulations of the early Universe.
https://www.mpa-garching.mpg.de/1109034/news20250129
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Astronomers have discovered a fascinating super-Earth planet in an exoplanetary system that will allow them to test the limits of habitability. Designated HD 20794 d, the planet follows a 647-day elliptical orbit that takes it from 0.7 to 1.5 astronomical units from the star. For half its orbit, it’s outside the habitable zone completely, then passes through the zone, reaching slightly inside the zone. Could life survive on a world like this?
https://www.unige.ch/medias/en/2025/une-super-terre-laboratoire-pour-la-quete-de-la-vie-dans-lunivers
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Stars form in regions of collapsing gas, but the process can get out of control, generating intense radiation that can push the clouds apart again. What keeps the process going? Astronomers have discovered that merging galaxies can generate giant magnetic fields that act like the lid on a pressure cooker to trap material and create the ideal conditions for star formation. New observations of a galaxy collision have found magnetic fields in the core of a merger.
https://cfa.harvard.edu/news/astronomers-detect-missing-ingredient-cooking-stars
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ESA has jumped into the lunar landing game, signing a contract with Thales Alenia Space to build its Argonaut lunar lander. Unlike other landers, Argonaut will be designed to handle the brutal day/night cycle on the Moon, with a primary mission length of 5 years. Each Argonaut will have a standard descent and cargo module and then have different payloads depending on the mission. It's hoped the first lander will fly in 2031.
https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Argonaut_a_first_European_lunar_lander
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When Freeman Dyson proposed the idea of a Dyson Sphere to surround a star, he quickly clarified that it would be more like a swarm of satellites in orbit. This is because a rigid body can't be in a stable orbit around a star; eventually, they'll crash. A new paper proposes a way that a rigid Dyson Sphere or a Ringworld could actually be stable. Surround a binary star system where the mass ratio between the two bodies is very small, and this creates a stable equilibrium.
https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/staf028/7989465?rss=1
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Mars is cold and dry today, but it was warmer and wetter billions of years ago, with flowing lakes and rivers. The Sun was fainter then, deepening the mystery. Researchers have long believed that atmospheric hydrogen was the key, mixing with carbon dioxide to provide a greenhouse effect. But atmospheric hydrogen is short-lived, so what was replenishing it? A new paper finds that warm periods were driven by crustal hydration, building hydrogen in the atmosphere.
https://seas.harvard.edu/news/2025/01/explaining-persistent-hydrogen-mars-atmosphere
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During the Martian winter, temperatures drop so low that carbon dioxide turns to snow and falls from the atmosphere to collect in a thin layer at the poles. When spring arrives on Mars, the carbon dioxide ice warms and turns into vapor, causing huge plumes of gas to erupt through the ice. This throws darker material into the surrounding regolith. This image of the process was captured by NASA's Mars Reconnaissance Orbiter in October 2018.
https://www.nasa.gov/image-article/geyser-season-on-mars/
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Astronomers have announced the discovery of a new asteroid with a non-zero chance of striking the Earth on December 22, 2032. Designated 2024 YR4, the space rock measures between 40 m and 100 m across, which would create regional damage if it struck the Earth. Initial observations estimate it has a 99% chance of passing the Earth safely but a 1% chance of hitting, which gives it a Level 3 designation on the Torino Impact Hazard Scale.
https://www.esa.int/Space_Safety/Planetary_Defence/ESA_actively_monitoring_near-Earth_asteroid_2024_YR4
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The Moon has a fraction of the mass of the Earth, and despite obvious evidence on its surface of volcanic activity, it's geologically dead today. Or maybe it's mostly dead. In a new study, researchers have discovered small ridges on the Moon's far side that are much younger than similar structures on the near side. These tectonic landforms could have been active as recently as within the last billion years, even 200 million years or so.
https://www.eurekalert.org/news-releases/1071951
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Japanese scientists have found that asteroid samples returned from NASA's OSIRIS-REx mission contain the building blocks of DNA and RNA. The researchers have detected all five nitrogenous bases, which serve as the raw materials for the molecules needed for life. They had already discovered two of these bases in Hayabusa 2 samples from asteroid Ryugu, but Bennu had all five. This shows that the raw materials for life could have been delivered by asteroids.
https://www.eurekalert.org/news-releases/1071865
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Jupiter's moon Io is the most volcanically active place in the Solar System. But thanks to new images from NASA's Juno spacecraft, we can see that it was even more volcanically active recently. Juno discovered a hot spot near Io's south pole that's larger than Lake Superior and blasts out erupting lava with six times the total energy of the world's power plants. This is the most powerful volcanic event ever seen in the Solar System.
https://www.nasa.gov/solar-system/nasa-juno-mission-spots-most-powerful-volcanic-activity-on-io-to-date/
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Astronomers have discovered thousands of exoplanets, many of which are in exoplanetary systems. They've found so many that they're starting to see some themes in the ways systems are organized. A new paper proposes that it's time to create a systematic way of classifying these multi-planet systems. About 80% are "peas-in-a-pod" systems with small, similarly sized planets and regular spacing. 8% are "warm Jupiter" systems with at least one giant planet and varied spacing.
https://arxiv.org/abs/2501.08191
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Astronomers have discovered an exoplanetary system with two gas giant planets that are messing up each other's orbit. One planet has 3.8 Jupiter masses and orbits every 82 days, while the other has 1.4 Jupiter masses. There's also a mini-Neptune world in the system. The two giant planets are locked in a 2:1 orbital resonance, and because of their gravitational interactions, the heavier planet can vary in its orbit by up to 4 days.
https://www.avcr.cz/en/media/press-releases/Violent-dance-of-massive-gas-giant-planets/
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When astronomers first detected the gravitational waves from a black hole merger, it was a revolution in astronomy. But it also opens up an interesting idea. Could gravitational waves be used to communicate? In a new paper, researchers consider the hypothetical ways that gravitational waves could be used as a communications method, both generating and detecting signals. Although this is well beyond our current technology, it's a fascinating direction to explore.
https://arxiv.org/abs/2501.03251
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https://www.nasa.gov/directorates/stmd/niac/fusion-enabled-comprehensive-exploration-of-the-heliosphere/
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