The risk of an asteroid impact has dropped, a private spacecraft is en route to the Moon, and titanium winds were discovered on an exoplanet. This Week in Space.
Asteroid Update
The estimated risk of asteroid 2024 YR4 impacting Earth in 2032 briefly rose to 3.1% last week—the highest probability ever calculated for such an event. However, as anticipated, it dropped to 1.5% by the week's end, and experts anticipate it will continue to decline, as we reported earlier.
Measuring between 40 and 90 meters in diameter, YR4 could cause significant local damage if it were to strike Earth. However, the current risk remains low and has already fallen to half its peak estimated probability. The asteroid is now moving away, and next month, NASA will observe it using the James Webb Space Telescope. These observations could provide more precise data on its size and help refine calculations of its trajectory.
YR4 will make another relatively close approach to Earth in 2028, offering a further opportunity to improve orbital calculations before its much closer pass in late 2032—though the chance of impact remains very low. If a significant impact risk is confirmed by then, defensive missions could be launched to alter its course, similar to NASA’s 2022 DART experiment.
The risk is decreasing and expected to drop further. The predicted trajectory of the asteroid, as calculated about a month ago. The empty circle represents the Moon’s orbit around Earth. | Source: NASA JPL/CNEOS
Firefly's Lunar Lander Moves Closer to the Moon
The American lunar lander developed by Firefly Aerospace, which was launched last month, entered lunar orbit two weeks ago and has moved into a lower orbit in preparation for its landing attempt in the coming days. Last Tuesday, the Blue Ghost lander fired its engines for 3 minutes and 18 seconds, adjusting its orbit to approximately 120 kilometers above the lunar surface. The company shared a video of the Moon's surface from this altitude on social media and reported that the lander is in good condition. Mission teams continue to monitor all of its systems whenever it is not beyond the Moon’s far side, ahead of the planned landing attempt on March 2.
Blue Ghost is a relatively large unmanned lander, comparable in size to a commercial van, with a dry mass of approximately 500 kilograms—three times that of Beresheet, the first Israeli spacecraft to reach the Moon. It was launched aboard a SpaceX Falcon 9 rocket as part of NASA’s CLPS program, which funds private lunar missions in preparation for future human landings under the Artemis program. The lander carries a range of scientific instruments and experiments, most of them for NASA, including an experiment on lunar dust adhesion to different surfaces, a mobile lab for analyzing dust composition, a dust-repulsion experiment using an electric field, a radiation-hardened computer to test its performance in space, and an X-ray camera for measuring the solar wind.
If Blue Ghost successfully lands, it will become the second private spacecraft to achieve a soft landing on the Moon, following Intuitive Machines’ lander last year. Meanwhile, another private lander, developed by Japan’s iSpace, which was launched alongside Blue Ghost, is also en route to the Moon. However, it is following a longer, more fuel-efficient trajectory and is expected to attempt landing only in the spring.
A close approach. The lunar surface as seen from the Blue Ghost lander at an altitude of 120 kilometers. | Source: Firefly Aerospace
Skies Full of Holes
Researchers analyzing data from the American DESI sky survey have identified no fewer than 2,500 active black holes in dwarf galaxies, along with approximately 300 intermediate-mass black holes, more than tripling the number of such objects previously known to science.
The DESI survey (Dark Energy Spectroscopic Instrument) is based on a spectrometer that measures the composition of light. It is mounted on a four-meter telescope operated by the U.S. National Science Foundation (NSF) on Kitt Peak, Arizona, and aims to image about 40 million galaxies over five years. Now in its fourth year, the project has released new findings based on data collected during its first few months. A research team led by postdoctoral researcher Ragadeepika Pucha (University of Utah) analyzed images of approximately 400,000 galaxies, about a third of them dwarf galaxies, in an effort to identify black holes at their centers.
Astrophysicists are fairly certain that all large galaxies, including our own Milky Way, have a supermassive black hole at their center. However, the picture is far less clear for smaller galaxies. Understanding black holes in dwarf galaxies could shed light on how galaxies form and evolve, as well as the role of black holes in these processes. Since detecting a black hole itself is extremely difficult—particularly in dwarf galaxies—the researchers focused on active black holes, which emit detectable energy as they consume surrounding material.
Pucha and her colleagues identified at least 2,500 dwarf galaxies that likely contain black holes, raising the estimated proportion of such galaxies to 2%, compared to 0.5% in previous studies. This surprising result suggests that many more small black holes exist in these galaxies than previously thought.
In a separate study, researchers identified about 300 intermediate-mass black holes in DESI data—more than doubling the number previously known, which stood at 100–150. Most known black holes are either small (less than 100 times the mass of the Sun) or supermassive (over a million times the Sun’s mass). While it was assumed that black holes in dwarf galaxies would typically fall within this intermediate range, the study found that only a quarter of the newly discovered intermediate-mass black holes are actually located in dwarf galaxies. This makes the findings even more intriguing and raises new questions about the relationship between galaxies and black holes.
"For example, is there a connection between the mechanisms that form black holes and the type of galaxy they reside in?" Pucha said. "The abundance of new findings will help us dig deeper into these mysteries and expand our understanding of black holes and their role in galaxy evolution."
“For example, is there any relationship between the mechanisms of black hole formation and the types of galaxies they inhabit?” Pucha said. “Our wealth of new candidates will help us delve deeper into these mysteries, enriching our understanding of black holes and their pivotal role in galaxy evolution.”
This wealth truly is remarkable. Pucha’s study is based on only 20% of the first-year DESI data. With the project now in its fourth year of a planned five-year mission, even more discoveries are likely on the horizon.
Short video on the findings:
Winds of Iron and Titanium Gusts
Not long ago, in a star system far, far away—though not too far in cosmic terms—researchers succeeded for the first time in mapping the three-dimensional structure of an exoplanet’s atmosphere. They identified distinct atmospheric layers and tracked powerful winds carrying metal compounds such as iron and titanium. “This planet’s atmosphere behaves in ways that challenge our understanding of how weather works — not just on Earth, but on all planets. It feels like something out of science fiction,” said Julia Victoria Seidel, a researcher at the European Southern Observatory (ESO) in Chile.
The planet in question is Tylo (WASP-121b), a gas giant similar to Jupiter that orbits a star in the Puppis constellation in the southern celestial hemisphere, about 900 light-years away. Unlike Jupiter, however, Tylo orbits extremely close to its star, completing an orbit in just 30 Earth hours. This proximity results in an extreme temperature contrast between the planet’s two hemispheres—one side exposed to the star is extremely hot, while the other, facing away, is significantly cooler. A large research team combined data from multiple instruments on ESO’s Very Large Telescope (VLT) to track the movement of elements such as hydrogen, sodium, and iron, representing Tylo’s upper, middle, and deeper atmospheric layers.
The findings, published in Nature, were surprising. “A jet stream rotates material around the planet’s equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side," Seidel said. "This kind of climate has never been seen before on any planet. Even the strongest hurricanes in the Solar System seem calm in comparison." Researchers also detected titanium just below the jet stream— an unexpected discovery, since previous studies of this exoplanet had failed to identify the element—possibly because it was hidden in relatively deep atmospheric layers.
As mentioned, Tylo is a massive, scorching gas giant. To conduct similar observations of atmospheres on Earth-like exoplanets and search for possible signs of life, researchers will have to wait for the completion of even larger telescopes, such as the Extremely Large Telescope (ELT), ESO's next-generation telescope, set to begin operations in Chile by the end of the decade.
A short simulation of Tylo’s atmospheric layers: