NASA’s Webb Telescope finds evidence for an underground ocean on Uranus moon Ariel, raising interest in future missions to explore the seventh planet and its moons.
Most familiar stars peacefully orbit the center of the Milky Way. But citizen scientists working on NASA’s Backyard Worlds: Planet 9 project have helped discover an object moving so fast that it will escape the Milky Way’s gravity and shoot into intergalactic space. This hypervelocity object is the first such object found with the mass similar to or less than that of a small star.
The Earth’s rotation has been decelerating throughout its history due to tidal dissipation, but the variation of the rate of this deceleration through time has not been established. We present a detailed analysis of eight geological datasets to constrain the Earth’s rotational history from 650 to 240 Mya. The results allow us to test physical tidal models and point to a staircase pattern in the Earth’s deceleration from 650 to 280 Mya. During this time interval, the Earth–Moon distance increased by approximately 20,000 km and the length of day increased by approximately 2.2 h. Specifically, there are two intervals with high Earth rotation deceleration, 650 to 500 Mya and 350 to 280 Mya, separated by an interval of stalled deceleration from 500 to 350 Mya. The interval with stalled deceleration is attributed mainly to reduced tidal dissipation due to the continent-ocean configuration at the time, not to changes in Earth’s dynamical ellipticity from continental assembly or glaciation. Modeling indicates that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth rotation. One potential implication of our findings is that the Earth’s tidal dissipation, along with Earth’s rotation deceleration, may play a role in the evolving Earth.
Dr. Caroline Dorn: “The larger the planet and the greater its mass, the more the water tends to go with the iron droplets and become integrated in the core.”
Do certain exoplanets mirror Earth regarding their distribution of iron and water? This is what a recent study published in Nature Astronomy hopes to address as an international team of researchers investigated the evolution of exoplanets and how they form their iron core with water residing either beneath or above the surface, and whether as a liquid or gas. This study holds the potential to help researchers better understand the formation and evolution of exoplanets, which will enable scientists to provide better targets for identifying Earth-like worlds throughout the cosmos.
For the study, the researchers use computer models to simulate the formation of planetary interiors on super-Earth and sub-Neptune exoplanets, specifically with a focus on the distribution of water within a planet’s interior in relation to the additional iron and metallic composition. In the end, the researchers found that longstanding hypotheses about the formation and evolution of water worlds are challenged given the model’s results that 95 percent or more of water on an exoplanet is stored within the planet’s interior, as opposed to the surface.
Continue reading “Iron and Water: How Exoplanets’ Interiors Challenge Traditional Models” »
Every clear night for the last three weeks, Bob Stephens has pointed his home telescope at the same two stars in hopes of witnessing one of the most violent events in the universe—a nova explosion a hundred thousand times brighter than the sun.
The eruption, which scientists say could happen any day now, has excited the interest of major observatories worldwide, and it promises to advance our understanding of turbulent binary star systems.
Yet for all the high-tech observational power that NASA and other scientific institutions can muster, astrophysicists are relying on countless amateur astronomers like Stephens to spot the explosion first.
Dr. Scott England: “As the aurora intensifies, you see more lights, but along with that, there’s more energy entering the atmosphere, so it makes the atmosphere near the poles very hot, which starts to push air away from the poles and towards the equator.”
How do powerful geomagnetic storms from the Sun influence the Earth’s atmosphere? This is what two separate studies (Karan et al. (2024) and Evans et al. (2024)) published in Geophysical Research Letters hopes to address as a team of researchers investigated how the geomagnetic storm that occurred between May 10–12, 2024—resulting in worldwide aurorae—impacted the Earth’s thermosphere, which is the Earth’s upper atmosphere extending approximately 70 miles to 130 miles above the Earth’s surface. This study holds the potential to help researchers better understand the short-and long-term effects of geomagnetic storms on the Earth’s atmosphere and how this could influence activities on the surface.
“The northern lights are caused by energetic, charged particles hitting our upper atmosphere, which are impacted by numerous factors in space, including the sun,” said Dr. Scott England, who is an associate professor in the Kevin T. Crofton Department of Aerospace and Ocean Engineering at Virginia Tech and a co-author on both studies. “During solar geomagnetic storms, there’s a lot more of these energetic charged particles in the space around Earth, so we see a brightening of the northern lights and the region over which you can see them spreads out to include places like the lower 48 states that usually don’t see this display.”
Continue reading “Geomagnetic Storm Brings Northern Lights to Unlikely Locations and Disrupts GPS” »
NASA’s Nancy Grace Roman Space Telescope is a next-generation observatory that will survey the infrared universe from beyond the orbit of the Moon. The spacecraft’s giant camera, the Wide Field Instrument, will be fundamental to this exploration. Data it gathers will enable scientists to discover new and uniquely detailed information about planetary systems around other stars. The instrument will also map how matter is structured and distributed throughout the cosmos, which could ultimately allow scientists to discover the fate of the universe. Watch this video to see a simplified version of how the Wide Field Instrument works. NASA’s Goddard Space Flight Center
Unprecedented Observational Capability
“That is a highlight of this building that it’s very close to talent — people who are still in this area because they just graduated,” said Knight, The Engine Accelerator’s president and chief executive.
The Engine Accelerator is where companies solving hard problems get off the ground. It’s part coworking space, with open desks, office suites, and conference rooms for rent. It’s part startup accelerator, hosting a high-octane circle of young scientists and engineers who need help turning their ideas into full-fledged operations.
If WeWork and Y Combinator had a baby, and that baby wanted to bring breakthrough research out of the lab and into the real world, it’d look something like The Engine.
Whenever and wherever stars are born, which occurs whenever clouds of gas sufficiently collapse under their own gravity, they come in a wide variety of sizes, colors, temperatures, and masses. The largest, bluest, most massive stars contain the greatest amounts of nuclear fuel, but perhaps paradoxically, those stars are actually the shortest lived. The reason is straightforward: in any star’s core, where nuclear fusion occurs, it only occurs wherever temperatures exceed 4 million K, and the higher the temperature, the greater the rate of fusion.
So the most massive stars might have the most fuel available at the start, but that means they shine brightly as they burn through their fuel quickly. In particular, the hottest regions in the core will exhaust their fuel the fastest, leading the most massive stars to die the most quickly. The best method we have for measuring “How old is a collection of stars?” is to examine globular clusters, which form stars in isolation, often all at once, and then never again. By looking at the cooler, fainter stars that remain (and the lack of hotter, bluer, brighter, more massive stars), we can state with confidence that the Universe must be at least ~12.5–13.0 billion years old.
These could be incredibly valuable to future astronauts hoping to settle on the moon, acting as a convenient shelter for a lunar base.
The cave is accessible through a pit in the well-studied Mare Tranquillitatis (Sea of Tranquility). This is a large basin made mostly of basalt. Neil Armstrong and Buzz Aldrin touched down in this region on July 20 1969.
While Mare Tranquillitatis isn’t likely to be the first place humans try to settle on the moon, the existence of one cave makes the existence of others very likely, so scientists now expect there to be others in locations more suitable for human settlement.
