Latest news with #JohnsHopkinsUniversityAppliedPhysicsLaboratory
Yahoo
16-04-2025
- Science
- Yahoo
A new NASA mission will make it a lot easier to predict space weather
We're in solar storm season. That's because 2025 is the peak of the sun's 11-year cycle of activity. Electrically charged particles fly from our neighborhood star into Earth's magnetosphere, where a powerful magnetic field surrounds our planet. From there, many things can happen – auroras, and even electrical shorts in satellites or power lines. How does that powerful solar energy get transmitted to Earth? A new NASA satellite series called the Electrojet Zeeman Imaging Explorer (EZIE) aims to fill in the gap. EZIE's three toaster-sized CubeSat satellites will spend at least 18 months circling our planet and watching how "space weather" operates near our planet — and how it can impact our infrastructure. "Satellites, power lines, that kind of thing can be affected" by solar storms, said principal investigator Sam Yee, a space scientist at the Johns Hopkins University Applied Physics Laboratory in Maryland. That's because the current of energy from the solar wind flowing through our atmosphere creates plasma through ionizations and heat through resistance, he added. "We call it a space weather event when the current gets stronger abruptly." Mighty currents have caused disruptions before. In 1989, solar storms shorted power for six million people in Quebec. Further back, an immense 1859 storm known as the Carrington Event set afire recording tape at telegraph stations. Scientists have warned that if another Carrington happens, we would be even more vulnerable today given how much of our lives depend on the electrical grid. EZIE will zero in on Earth's auroral electrojets — which are electrical currents flowing close to the magnetic poles of our planet. At the edge of space, which is roughly 65 miles or 100 km above our planet, these electrojets carry currents of up to a million amps of electricity. "You often see this on the night side of the earth — a big burst of activity," said Ian Mann, a University of Alberta physicist not involved with the mission. This activity results in "big dancing displays of the Northern Lights and large electrical currents, and that can happen very quickly. And if it happens quickly, that means that the magnetic fields change quickly." The magnetic fields can be measured through the Zeeman effect of radiative emissions of atoms and molecules. These emission lines can split into several components in the presence of a magnetic field, caused by the interaction between the internal magnetic moments of the emitting atoms and molecules with the external magnetic field. We can see these splits in the spectrum of light emitted by these atoms and molecules. EZIE aims to use its trio of satellites to remotely quantify the Zeeman effects of the molecular oxygen emission line. It will measure magnetic fields induced by the presence of the electrical current in the upper atmosphere in different locations, especially during space weather events. In other words, EZIE will generate a "current map" – a map of the structure of the current – in the field of view of the satellites, Yee said. More importantly: "If we put a multiple spacecraft flying over that region at the same time, we can see that structure, [and] how a structure changes with time." While we can infer the currents from the ground, the distance away from the Earth where the currents flow means that mapping their detailed structure that way is challenging. The University of Alberta, for example, manages and operates the CARISMA magnetometer network. The acronym stands for Canadian Array for Realtime Investigations of Magnetic Activity, part of a multi-university project called Space Environment Canada, funded by the Canadian Space Agency, with additional support from the Canada Foundation for vast CARISMA magnetometer array runs thousands of miles from Canada's north to close to the border of the United States, and from east to west, spanning a large region of western Canada. Despite this coverage of sensors measuring the magnetic field, "diagnosing the detailed fine structure is a nightmare," Mann said, since the magnetic effects from smaller scale structures can magnetically cancel on the ground. Such features can then fall below the resolution of the network, meaning they will smear out in the data. And from above, "you only typically have an occasional satellite that flies through it." Mann said the ideal would be "to have a huge network of satellites all flying at the same time, and by mapping their magnetic fields locally such a constellation of satellites could tell you something about what's actually happening" as the space storms develop. Besides EZIE, he said the community has been fortunate to get some information from the AMPERE experiments aboard the Iridium satellite network. The resolution of AMPERE (Active Magnetosphere and Planetary Electrodynamics Response Experiment) is much lower, however. "The resolution in space and time is still determined by the pass-through time of the spacecraft," Mann said. "The satellites in the AMPERE constellation are about 10 minutes apart along their orbits, and a lot can happen in 10 minutes." During EZIE overflights of the electrojets, the three EZIE satellites will assess the spatial and temporal development of the magnetic fields — which are the signatures of the electrojets. EZIE data will therefore help scientists to better understand how space storms develop, and how sothey can adversely impact technological infrastructure on the ground and in space. Solar storms create beautiful displays when they generate auroras, but the stakes are more serious when they affect power grids or satellites. EZIE aims to help us better understand the flow of currents, to protect our infrastructure. That way, we can both enjoy the beautiful northern lights – and rest easy knowing the lights will still be on when we go back inside.
Yahoo
03-04-2025
- Science
- Yahoo
Remember that asteroid everyone was worried about 2 months ago? The JWST just got a clear view of it
When you buy through links on our articles, Future and its syndication partners may earn a commission. For a few weeks in January and February this year, asteroid 2024 YR4 had us all worried. Shortly after it was discovered, astronomers calculated that the asteroid had a 1-in-83 chance of hitting Earth in 2032 — that's an impact risk of around 1%. Experts urged caution, though noting that the impact odds were likely to fall significantly. Sure enough, by late February, the probability of the asteroid hitting Earth fell to near zero. This asteroid, however, is still worth analysis in its own right. As such, scientists recently turned the James Webb Space Telescope's (JWST) powerful gaze towards 2024 YR4, capturing the object in both visible and thermal light. The team measured the asteroid to be around 200 feet (60 meters) in diameter. "That's just about the height of a 15-story building," Andy Rivkin of the Johns Hopkins University Applied Physics Laboratory said in a statement. The JWST also helped scientists study how quickly the space rock heats up and cools down. According to Rivkin, these thermal properties in 2024 YR4 are "not like what we see in larger asteroids," likely due to the fact that it spins very quickly and that its surface is "dominated by rocks that are maybe fist-sized or larger," rather than fine grains of sand. Rivkin said studying asteroids like 2024 YR4 with the JWST is "invaluable" for helping scientists figure out how our space telescopes might aid planetary defense efforts if another "possible impactor" is found down the line. "All together, we have a better sense of what this building-sized asteroid is like," Rivkin said. "This will help us determine the best approach to use during a more urgent observing program should another asteroid pose a potential impact threat in the future." A study about the JWST's observations of asteroid 2024 YR4 were published in the journal Research Notes of the AAS.
Yahoo
11-02-2025
- Science
- Yahoo
Deep Chasms Could Lead to a Hidden Ocean on Uranus's Moon Ariel
Our Solar System, like a sneaky little hobbit, seems to have stuffed its pockets full of hidden oceans. Jupiter, Saturn, Uranus, and Neptune all have moons astronomers think might be harboring liquid oceans, locked away beneath thick icy shells. Those shells are a big problem for Earth-based scientists who desperately want to take a peek at those liquid centers, but one moon may be wearing its heart on its sleeve. The surface of Uranus's moon Ariel is scored with deep chasms – and those may contain deposits disgorged from below. Those include carbon dioxide ice and other carbon-bearing deposits that may have resulted from chemical processes taking place inside the little moon. If this is the case, it means those gorges could be a way to study the interior of this ocean world without having to undertake more dramatic research efforts. "If we're right, these medial grooves are probably the best candidates for sourcing those carbon oxide deposits and uncovering more details about the moon's interior," says planetary geologist Chloe Beddingfield of Johns Hopkins University Applied Physics Laboratory. "No other surface features show evidence of facilitating the movement of materials from inside Ariel, making this finding particularly exciting." The chasms on the surface of Ariel are fascinating. Some of their floors are scored by parallel grooves which are among the youngest known geological features visible on the moon. It's not clear how they got there, but a lot depends on what the moon has going on beneath its surface. Previous studies suggested that they may be the result of an interaction between tectonic and volcanic activity, but the specifics have been difficult to pin down. Beddingfield and her colleagues used observation data and formation models to see if they could fill in the gaps. They were able to show that a process that takes place on Earth could be responsible for the marks we see on Ariel. Known as spreading, that process takes place on volcanic ridges here on Earth, where the seafloor parts and material rises up from below to form a new part of the crust. On Ariel, spreading could occur when warmer material surges upwards from below, splitting the moon's crust before filling the crack it created. The researchers found that when they joined the two edges of Ariel's chasms as if zipping them back up, the two sides matched perfectly; and the parallel grooves seen at the floors of some of the chasms are consistent with materials being deposited over time. There are a number of reasons this is interesting. Uranus' moons have, in the past, entered orbital lockstep, in which their orbital periods formed precise ratios known as resonance. Orbital resonance results in a gravitational push-pull that produces internal heating, melting, and refreezing. Such periods of resonance could be what drove changes on Ariel's surface; but they could also produce hidden oceans by making moons' interiors warm enough to sustain liquid, briny water. Recent observations from the JWST strongly hint that such an ocean is present on Ariel. If this is the case, the ocean could be responsible for the carbon dioxide ice seen on the moon's surface and in its chasms, but as yet we have too little information to know. "The size of Ariel's possible ocean and its depth beneath the surface can only be estimated, but it may be too isolated to interact with spreading centers," Beddingfield says. "There's just a lot we don't know. And while carbon oxide ices are present on Ariel's surface, it's still unclear whether they're associated with the grooves because Voyager 2 didn't have instruments that could map the distribution of ices." We're well past due to send an exploration mission to Uranus and Neptune. Let's add Ariel's mystery grooves to the list of things to look at when it finally happens. Chop chop, space agencies! The research has been published in The Planetary Science Journal. A Strange New Cosmic Explosion May Have Just Been Discovered Astronomers Amazed by Perfect 'Einstein Ring' Gleaming in Space Astronomers Capture Breathtaking Image of Newborn Star Taking Shape
