Andy has been interested in space exploration ever since reading Pale Blue Dot in middle school. An engineer by training, he likes to focus on the practical challenges of space exploration, whether that's getting rid of perchlorates on Mars or making ultra-smooth mirrors to capture ever clearer data. When not writing or engineering things he can be found entertaining his wife, four children, six cats, and two dogs, or running in circles to stay in shape.
We’re getting closer and closer to finding a real Earth-like exoplanet. But finding one is only half the battle. To truly know if we’re looking at an Earth analog somewhere else in the galaxy, we have to directly image it too. That’s a job for the Habitable Worlds Observatory (HWO), a planned space-based telescope whose primary job is to do precisely that. But even capturing a picture and a planet and getting spectral readings of its atmospheric chemistry still isn’t enough, according to a new paper available in pre-print on arXiv by Kaz Gary of Ohio State and their co-authors. HWO will need to figure out how much a planet weighs first.
Astronomers have long argued that dark matter is the invisible scaffolding that holds galaxies together. Without its immense gravitational pull, the rotational spins of galaxies would force them to simply fly apart. But now, scientists have found a string of galaxies that seem to be missing their dark matter entirely. The latest in this string, known as NGC 1052-DF9, is described in a new paper, available in pre-print on arXiv, by Michael Keim, Pieter van Dokkum and their team from Yale. It lends credence to a radical theory of galaxy formation known as the “Bullet Dwarf” collision scenario, which has been a controversial idea for the last decade.
The early universe is absolutely so far outside our understanding of how the world works it's hard to describe in words. Back then, the cosmos wasn’t filled with stars and galaxies but with a boiling soup of quarks and gluons, with a few microscopic black holes thrown in, occasionally detonating like depth charges. That’s the early universe theorized by a new paper, available in pre-print from arXiv, from researchers at Vrije Universiteit Brussel and MIT anyway.
If you thought the current crop of satellite megaconstellations was bad, you’re going to be horribly disappointed by new proposals from both SpaceX and a company called Reflect Orbital. Their combined plans would fundamentally alter the night sky as we know it, and the global astronomical community is sounding the alarm - most notably letters from the Royal Astronomical Society (RAS), the European Southern Observatory (ESO), and the International Astronomical Union (IAU) strongly opposing the plan, which currently sits with America’s Federal Communications Commission (FCC) for approval.
It’s amazing how much one movie can act as a cultural touchpoint for an entire topic - even a topic as serious as defense of a planet. Popular media consistently use the 1998 movie Armageddon as a reference when talking about how we would destroy a civilization-ending asteroid. That’s despite the movie’s glaring scientific flaws, not the last of which is the likely size of the rogue comet that threatens the Earth. Planetary defense researchers at MIT were recently interviewed by the university’s media department as part of their “3 Questions” series. One of the most important takeaways is that the size of any likely planetary impactor in our lifetime is going to be much smaller than the kilometer-sized behemoth that did in Bruce Willis’ character - but we could face a threat from a handful of them before the end of the century.
In September 2022, humanity crashed a spacecraft into an asteroid - on purpose. The objective of NASA’s Double Asteroid Redirection Test (DART) was to see if we could intentionally modify the orbit of Dimorphos, the small moonlet orbiting the larger asteroid Didymos. According to all accounts, the mission worked spectacularly, but it was a one-way trip, so our ability to see what happened to the binary asteroid system has so far been limited to ground-based telescopes. That wasn’t good enough for the planetary defense community, so they planned a follow up mission called Hera, which, according to a recent press release from its operator, the European Space Agency (ESA), just successfully completed its most dramatic deep-space orbital maneuver.
Venus is increasingly becoming a touch point for our studies of the exoplanets, as missions like the James Webb Space Telescope (JWST)and the upcoming Habitable Worlds Observatory (HWO) begin to characterize rocky exoplanets around other stars. Understanding the difference between the evolutions of Venus and Earth, which ended up with such different results, is a key to understanding whether we might be looking at an Earth-analogue or a hellish landscape like Venus. A new paper by Rodolfo Garcia of the University of Washington and his colleagues, which is available in pre-print form on arXiv, simulates Venus’ 4.5 billion year evolution as part of the solar system to try to understand some of those differences.
We’re getting close to launch day for Dragonfly! Engineers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, have officially kicked off the integration and testing stage for the car-sized, nuclear-powered helicopter bound for Saturn’s largest moon, Titan. According to a press release for APL, after years of designing, tweaking, and testing individual components in laboratories and on computer simulations, various organizations have started testing actual hardware ahead of the mission’s planned 2028 launch.
Heat shield design is one of the most critical aspects of missions that plan to either land on a planet’s (or moon’s) surface or return to our own. Spacecraft that have to survive the fiery, hypersonic plunge through an atmosphere require these systems. For decades, heat shields have been designed to slowly burn away in a process called ablation, which is intended to dissipate the incredible thermal energy or reentry. But, there’s another, less understood phenomenon that affects them too - spallation, where a heat shield sheds material in violent, unpredictable “bursts”. This second mode of destruction seems to be particularly prevalent in oxygen-deprived atmospheres, like that of Titan, where the Dragonfly helicopter plans to land in the not too distant future. A new paper published in Carbon from researchers at the University of Illinois Urbana-Champaign (UIUC) performed some tests showing just how different those heat shields might need to be.
Space weather is a fascinating subject, but one we still have a lot to learn about. One of the main components of it is the active regions (ARs) of the Sun. These huge concentrations of magnetic fields show up throughout the Sun’s photosphere and are the primary source of solar flares and coronal mass ejections (CMEs). They can be simple pairings of magnetic flux or huge, magnetically complex tangles that spend weeks creating massive solar storms before dissipating. But tracking the longest lived of these ARs has been a headache for solar physicists, and a recent paper by Emily Mason and Kara Kniezewski, published in The Astrophysical Journal, both dives into this tracking problem and uncovers some interesting features of the Sun’s most persistent ARs.
In 1959, the Luna 2 probe from the Soviet Union became the very first human-made object to reach our closest celestial neighbor. In the decades since, we have been leaving footprints - both literally and figuratively - all over the Moon. Today, there are over 100 metric tons of human-made material resting on the Moon’s surface - everything from advanced cameras and sensors to literal human waste. But that’s nothing compared to what’s to come. NASA predicts the next decade will see over 100 new lunar missions, equaling or exceeding all the missions previously flown. Which brings up a pressing question about all the stuff that’s already there - how do we protect that history? A new paper by Teasel Muir-Harmony, the Curator of the Space History Department of the Smithsonian and Todd Mosher, a Scholar in Residence at University of Colorado, Boulder, reports on a Smithsonian National Air and Space Museum and the American Institute of Aeronautics and Astronautics Summit on Outer Space Heritage that dives into the legal, scientific, and engineering hurdles of preserving these historic sites.
The European Space Agency’s (ESA’s) Jupiter Icy Moons Explorer (JUICE) probe is on its (very long) way to Jupiter, and will finally arrive at the King of Planets in 2031. Its primary mission is to focus on the “big three” icy moons - Ganymede, Europa, and Callisto. But while JUICE is busy mapping Ganymede’s magnetic field, it will also be keeping a sharp eye on the other 94 moons in the Jupiter system. A recent paper published in Space Science Reviews by Tilmann Denk of DLR, Germany’s space research association, and his co-authors showcases just how much “bonus science” JUICE is expected to squeeze out of these other targets.
Greek mythology has given a name to a great many objects in our solar system. But perhaps one of the least well understood are the Trojans, named after the people of Troy featured in The Iliad. When astronomers refer to them, they are normally talking about a group of over 10,000 confirmed asteroids orbiting at the Lagrange points both in front of and behind Jupiter on its orbit around the Sun. But, more generally, astronomers can now use the term to refer to any co-orbital setup - indeed almost every planet in our solar system has Trojans, though not as many as Jupiter. Which also leads to the belief that “exotrojans” must exist around other stars. Despite our best efforts with initiatives like the TROY project, so far we have yet to find one. But a new paper published in The Astrophysical Journal by Jackson Taylor of West Virginia University and an abundance of co-authors took the hunt to one of the most extreme environments in the universe: pulsar binary systems.
Oxygen has been the most important gas in our search for life among the cosmos thus far. On Earth, we have it in abundance because it is produced by biological synthesis. But that might not be the case on other planets, so even if we do find a very clear high oxygen signal in the atmosphere of an exoplanet, it might not be a clear indication that life exists there. A new paper, available in pre-print on arXiv, from Margaret Turcotte Seavey and a team of researchers from institutions like the NASA Goddard Space Flight Center and Johns Hopkins University, adds some additional context to what else might be going on in those atmospheres. In particular, they note that if there’s even a little bit of water vapor, it can make a big difference in whether a lifeless rock looks like a living, thriving world.
Every ounce counts when launching a rocket, which is why considerations for the Size, Weight, and Power (SWaP) of every component matters so much. For decades, one of the heaviest and most power-hungry components on a spacecraft has been its optical and communications hardware - specifically the bulky mechanical mirror used for LiDAR and free-space laser communications. But a new paper, published in Nature by researchers at MIT, MITRE, and Sandia National Laboratories, might have just fundamentally changed the SWaP considerations of LiDAR systems. Their technology, which they’re called a “photonic ski-jump” could one day revolutionize how spacecraft communicate.
One particularly well known fact about the Moon is that it doesn’t have much of a magnetosphere to speak of. There’s no blanket to protect it from the solar wind ravaging its surface, blowing away its atmosphere and charging the notoriously dangerous dust particles that make up its regolith. However, scientists have also known for around 60 years that some parts of the moon do experience sudden spikes in a magnetic field - some of which are up to 10 times stronger than the background magnetization. Since their discovery, these “lunar external magnetic enhancements” (LEMEs) have puzzled researchers - what was causing them, and why did they reach so high above the lunar surface that spacecraft could see them? A new paper published in The Astrophysical Journal Letters by Shu-Hua Lai and her colleagues at the National Central University in Taiwan explains for the first time what is likely causing these LEMEs - a novel type of the Kelvin-Helmholtz instability.
“Follow the water” has been a guiding mantra of astrobiology, and even space exploration more generally for decades. If you want to find life, it makes sense to look for the universal solvent that almost all types of life on Earth use. But what if life doesn’t actually need water to live or even evolve? A recent paper, available in pre-print on arXiv by researchers at MIT, including Dr. Sara Seager, and the University of Cardiff, proposes an alternative to water as the basis for life - ionic liquids (ILs) and deep eutectic solvents (DES). These liquids could allow life to exist in environments we had once thought were far too hot, too cold, or too barren to support life, and could dramatically change our search for it throughout the cosmos.
Traditional chemical rockets, though they are the most commonly used propulsion method for space exploration today, are beholden to the tyranny of the rocket equation. Every ounce of thrust they use must also start out as fuel, which means the rocket itself will have to weigh more, and weight is one of the limiting factors in how fast a propulsion system can go. So, scientists have been searching for, and actively testing, alternatives for decades. One of the most promising is the solar sail - a huge reflective sheet that uses sunlight, or in some cases a “pushing laser” to maneuver about the solar system without any onboard propellant necessary. A recent paper published in the Journal of Nanophotonics by Dimitar Dimitrov and Elijah Taylor Harris of Tuskegee University describes a new type of light sail that solves some of the major problems of existing designs.
Back in the early 2000s, my computer screen, like that of many other space enthusiasts, was typically covered in a series of rainbow-colored spectral signals. As my computer crunched through thousands of data points of radio signals collected by the SETI@Home initiative, I was hoping I was in some small way contributing to one of humanity’s greatest scientific endeavours - the search for extraterrestrial life. But, according to a new paper published in The Astrophysical Journal by Vishal Gajjar and Grayce Brown of the SETI Institute, it seems unlikely that the signals SETI@Home was tailored to look for actually exist. That doesn’t mean there weren’t aliens yelling into the void at the top of their electronic lungs, but simply that the space weather from their local star might have changed the signal to make it unrecognizable by the time it reached us.
Scientists occasionally have a hard time figuring out whether data they are seeing is an actual physical phenomenon or just a trick of their instrumentation. A new paper in The Planetary Science Journal from Jessica Sunshine and their colleagues at the University of Maryland describes one such confusing scenario. In this case, the researchers noted some fan-like patterns across the surface of Dimorphos, the asteroid hit by NASA’s DART mission, and thought it might be a trick of their camera. But after some image correction, computation, and physical experimentation, they determined the patterns were caused by the first-ever documented cases of material transfer between two asteroids.
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