New research from the Cool Worlds Lab! Check out our explainer of this important new paper to be published in Nature Astronomy soon. Edited by Jorge Casas
Astronomers have found evidence for what might be a planet with about half the mass of the Moon orbiting the pulsar PSR J0337+1715 – this would make it the least massive planet we have ever detected outside our Solar System. The pulsar and the objects that orbit it are already some of the most extreme and extraordinary we know, so any potential planet must have undergone an extraordinary journey of survival.
NASA analysis of a near-Earth asteroid, designated 2024 YR4, indicates it has a more than 1% chance of impacting Earth on Dec. 22, 2032 – which also means there is about a 99% chance this asteroid will not impact. Such initial analysis will change over time as more observations are gathered. Currently, no other known large asteroids have an impact probability above 1%. Asteroid 2024 YR4 was first reported on Dec. 27, 2024, to the Minor Planet Center– the international clearing house for small-body positional measurements – by the NASA-funded Asteroid Terrestrial-impact Last Alert System station in Chile. The asteroid, which is estimated to be about 130 to 300 feet wide, caught astronomers’ attention when it rose on the NASA automated Sentry risk list on Dec. 31, 2024. The Sentry list includes any known near-Earth asteroids that have a non-zero probability of impacting Earth in the future. An object that reaches this level is not uncommon; there have been several objects in the past that have reached this same rating and eventually dropped off as more data have come in. New observations may result in reassignment of this asteroid to 0 as more data come in.
What do we know?Near-Earth asteroid 2024 YR4 was discovered on 27 December 2024 at the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile.Shortly after its discovery, automated asteroid warning systems determined that the object had a very small chance of potentially impacting Earth on 22 December 2032. 2024 YR4 is estimated to be between 40 m and 100 m wide. An asteroid this size impacts Earth on average every few thousand years and could cause severe damage to a local region.As a result, the object rose to the top of ESA’s asteroid risk list. Since early January, astronomers have been carrying out priority follow-up observations using telescopes around the world and using the new data to improve our understanding of the asteroid’s size and trajectory.As of 29 January 2025, ESA estimates that the probability that asteroid 2024 YR4 may impact Earth on 22 December 2032 is 1.2%. This result is consistent with independent estimates made by NASA’s Center for Near-Earth Object Studies (CNEOS) and NEODyS.Asteroid 2024 YR4 is now rated at Level 3 on the Torino Impact Hazard Scale: a close encounter that warrants attention from astronomers and the public. It is important to remember that an asteroid’s impact probability often rises at first before quickly dropping to zero after additional observations. For an explanation of why this happens, see the video below:
An international team has confirmed the discovery of a super-Earth orbiting in the habitable zone of a nearby Sun-like star. The planet was originally detected two years ago by Oxford University scientist Dr Michael Cretignier. This result, drawing on over two decades of observations, opens a window to future studies of Earth-like exoplanets that may have conditions suitable for life. The findings have been published in Astronomy & Astrophysics.
The new planet, named HD 20794 d, has a mass six times that of Earth and orbits a star similar to our Sun, located just 20 light years away. Its orbit places it within the habitable zone of the system, meaning it is at the right distance from its star to sustain liquid water on its surface, a key ingredient for life as we know it.
Although the planet is located in the system’s habitable zone, it is too early to say whether it could host life. Unlike most planets, HD 20794 d’s orbit is not circular but elliptical. Its distance from its star changes significantly, causing the planet to move from the outer edge of the habitable zone to the inner edge throughout its year.
To quote Professor Farnsworth “Good news everyone!!!” 'City-killer' asteroid has a 1-in-83 chance of smashing into Earth in 2032, NASA sayshttps://www.livescience.com/space/asteroids/city-killer-asteroid-has-a-1-in-83-chance-of-smashing-into-earth-in-2032-nasa-says
While we can’t say for sure where YR24 would strike our planet, we can geographically constrain where Earth would possibly take the hit based on the projected impact date of December 22, 2032, says Daniel Bamberger, an amateur astronomer in Germany, who has calculated the asteroid’s possible impact corridor. The area under threat is a swath extending from the Pacific Ocean through northern South America, the Atlantic Ocean, sub-Saharan Africa, the Arabian Sea and parts of South Asia. “We knew we would one day find such an object with a reasonably high chance of impact,” he says.
In the unlikely event that 2024 YR4 hits the Earth in 2032, it would impact at a high velocity, roughly 17 kilometers per second (about 38,000 miles per hour).
Physicists have performed a simulation they say sheds new light on an elusive phenomenon that could determine the ultimate fate of the universe.Pioneering research in quantum field theory around 50 years ago proposed that the universe may be trapped in a false vacuum—meaning it appears stable but in fact could be on the verge of transitioning to an even more stable, true vacuum state.While this process could trigger a catastrophic change in the universe's structure, experts agree that predicting the timeline is challenging, but it is likely to occur over an astronomically long period, potentially spanning millions of years.
They used a 5,564-qubit quantum annealer, a type of quantum machine designed by D-Wave Quantum Inc. to solve complex optimization problems—which involve finding the best solution from a set of possible solutions—by harnessing the unique properties of quantum-mechanical systems.In the paper, published in Nature Physics, the team explain how they used the machine to mimic the behavior of bubbles in a false vacuum.
Using data from the European Space Agency’s Gaia mission, scientists have found a huge exoplanet and a brown dwarf. This is the first time a planet has been uniquely discovered by Gaia’s ability to sense the gravitational tug or ‘wobble’ the planet induces on a star. Both the planet and brown dwarf are orbiting low-mass stars, a scenario thought to be extremely rare.
When the next batch of Gaia data is released in 2026, it will contain 5.5 years of mission data that could uncover hundreds – if not thousands – of planets and brown dwarfs around nearby stars. That will give us new insights into how these different objects form, and Gaia is paving the way for a new era of astrometric discovery, leading to a deeper understanding of the diverse planetary systems that populate our galaxy.ESA Research Fellow Matthew Standing is an exoplanet expert. “This discovery is an exciting tip-of-the-iceberg for the exoplanet discoveries we can expect from Gaia in the future,” he explains. “The discovery of Gaia-4b is an important breakthrough in the use of Gaia astrometry for exoplanet detection, complimenting the other exoplanet detection methods used by ESA’s Cheops and the upcoming Plato mission.”
My take on Asteroid 2024 YR4, which currently has a 2.3% chance of colliding with the Earth in 2032, an event that's likely comparable to a multi megaton nuclear weapon. The odds are still good that it'll miss, but the chances may look worse before they get better, and there's a real chance we can't honestly know the answer by April when it gets too faint to observe until 2028.But this won't be the end of the world, and might be an opportunity to put the capabilities of DART into real world use.
The monster jet spans at least 200,000 light-years and formed when the Universe was less than 10% of its current age
Euclid blasted off on its six-year mission to explore the dark Universe on 1 July 2023. Before the spacecraft could begin its survey, the team of scientists and engineers on Earth had to make sure everything was working properly. During this early testing phase, in September 2023, Euclid sent some images back to Earth. They were deliberately out of focus, but in one fuzzy image Euclid Archive Scientist Bruno Altieri saw a hint of a very special phenomenon and decided to take a closer look.“I look at the data from Euclid as it comes in,” explains Bruno. “Even from that first observation, I could see it, but after Euclid made more observations of the area, we could see a perfect Einstein ring. For me, with a lifelong interest in gravitational lensing, that was amazing.”
Astronomers may have discovered a scrawny star bolting through the middle of our galaxy with a planet in tow. If confirmed, the pair sets a new record for the fastest-moving exoplanet system, nearly double our solar system’s speed through the Milky Way.The planetary system is thought to move at least 1.2 million miles per hour, or 540 kilometers per second.“We think this is a so-called super-Neptune world orbiting a low-mass star at a distance that would lie between the orbits of Venus and Earth if it were in our solar system,” said Sean Terry, a postdoctoral researcher at the University of Maryland, College Park and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Since the star is so feeble, that’s well outside its habitable zone. “If so, it will be the first planet ever found orbiting a hypervelocity star.”
The largest solar storm in two decades hit Earth in May 2024. For several days, wave after wave of high-energy charged particles from the Sun rocked the planet. Brilliant auroras engulfed the skies, and some GPS communications were temporarily disrupted.With the help of a serendipitously resurrected small NASA satellite, scientists have discovered that this storm also created two new temporary belts of energetic particles encircling Earth. The findings are important to understanding how future solar storms could impact our technology.
China has begun recruiting for a planetary defence force after risk assessments determined that an asteroid could conceivably hit Earth in 2032.Job ads posted online by China’s State Administration of Science, Technology and Industry for National Defence (SASTIND) this week, sought young loyal graduates focused on aerospace engineering, international cooperation and asteroid detection.
Which brings us to the present, or more accurately, to February 6, 2025. On that date, a gravitational wave event of high significance was detected: an event that definitely contains a neutron star and that either represents a neutron star-neutron star or neutron star-black hole merger, with a combined mass that’s on the relatively low end: no more than five solar masses and possibly as low (or lower than) three solar masses.
And then, only about an hour after that event was automatically reported, complete with sky-localization coordinates, the IceCube Collaboration issued a follow-up alert of their own. They searched for any possible neutrino signatures occurring within 1000 seconds (about 17 minutes) of the gravitational wave event, that were also consistent with the possible locations of the source from gravitational wave observations. A coincidence in space and in time would be very promising, especially considering the estimated distance to this event, from gravitational waves, is fairly large: at about ~1.1 ± 0.3 billion light-years.Lo and behold, there were two candidates, one of which is an outstanding match: occurring less than five minutes after the gravitational wave event finished.
If there turns out to be an afterglow, or any type of remnant to observe at any wavelength of light, associated with the gravitational wave and neutrino signatures of the event that’s presently called S250206dm, this will mark the greatest gravitational wave detection in history: our first trifecta event in the history of multi-messenger astronomy. It’s worth keeping in mind, however, that the scientists working on this are being slow and careful, and are taking the time they need to get the science right and collect the full suite of relevant data. Only after there’s a completed analysis will we know for sure what happened during this event, and just what its cosmic implications are.
New research to be published in the Planetary Science Journal examines how much material from AC could reach our Solar System and how much might already be here. It’s titled “A Case Study of Interstellar Material Delivery: Alpha Centauri.” The authors are Cole Greg and Paul Wiegert from the Department of Physics and Astronomy and the Institute for Earth and Space Exploration at the University of Western Ontario, Canada.“Interstellar material has been discovered in our Solar System, yet its origins and details of its transport are unknown,” the authors write. “Here we present Alpha Centauri as a case study of the delivery of interstellar material to our Solar System.” AC likely hosts planets and is moving toward us at a speed of 22 km s?1, or about 79,000 km per hour. In about 28,000 years it will reach its closest point and be about 200,000 astronomical units (AU) of the Sun. According to Greg and Wiegert, material ejected from AC can and will reach us, and some is already here.
