Enlarge/ Artist’s illustration of NASA’s Psyche spacecraft, set to launch in August 2022. The Psyche mission will explore a metal-rich asteroid of the same name that lies in the main asteroid belt between Mars and Jupiter.
NASA/JPL-Caltech/ASU
Ars Technica had the opportunity to tour NASA’s Jet Propulsion Laboratory in California this week, suiting up for a clean room sneak peek at the Psyche spacecraft now nearing completion. This ambitious mission, named after the eponymous asteroid it will explore, is due to launch in August on a Falcon Heavy rocket. Scientists are hopeful that learning more about this unusual asteroid will advance our understanding of planet formation and the earliest days of our solar system.
Discovered in March 1852 by the Italian astronomer Annibale de Gasparis, 16 Psyche is an M-type asteroid (meaning it has high metallic content) orbiting the Sun in the main asteroid belt, with an unusual potato-like shape. The longstanding preferred hypothesis is that Psyche is the exposed metallic core of a protoplanet (planetesimal) from the earliest days of our solar system, with the crust and mantle stripped away by a collision (or multiple collisions) with other objects. In recent years, scientists concluded that the mass and density estimates aren’t consistent with an entirely metallic remnant core. Rather, it’s more likely a complex mix of metals and silicates.
Alternatively, the asteroid might once have been a parent body for a particular class of stony-iron meteorites, one that broke up and re-accreted into a mix of metal and silicate. Or perhaps it’s an object like 1 Ceres, a dwarf planet in the asteroid belt between the orbits of Mars and Jupiter—except 16 Psyche may have experienced a period of iron volcanism while cooling, leaving highly enriched metals in those volcanic centers.
Enlarge/ Multiple views of 16 Psyche imaged by the Very Large Telescope.
Scientists have long suspected that metallic cores lurk deep within terrestrial planets like Earth. But those cores are buried too far beneath rocky mantles and crusts for researchers to find out. As the only metallic core-like body discovered, Psyche provides the perfect opportunity to shed light on how the rocky planets in our solar system (Earth, Mercury, Venus, and Mars) may have formed. NASA approved the Psyche mission in 2017, intending to send a spacecraft to orbit the asteroid and collect crucial data about its characteristics.
“Our understanding of what Psyche might be has not changed all that much over the last few years,” Linda Elkins-Tanton of Arizona State University, principal investigator of the Psyche mission, told Ars. “It has to have a large metal content, but we’ve never really known how much. It could be the part of a metal core of a tiny planet from early in the solar system, or it could be something that never melted and formed a core but has metal mixed into it, like pebbles with the rock. We won’t really know until we get there.”
Several instruments will be aboard the Psyche spacecraft to collect that precious scientific data. There is a multi-spectral imager capable of producing sufficiently high-resolution images for scientists to tell the difference between the asteroid’s metallic and silicate (mineral) constituents. The job of mapping the asteroid’s composition and identifying all the elements falls to a gamma ray and neutron spectrometer. There is also a magnetometer that will measure and map any remnants of a magnetic field. Finally, a microwave radio telecommunications system will also be able to measure the asteroid’s gravity field, gleaning clues about its interior structure.
Enlarge/ A miniature model of the Psyche spacecraft.
Jennifer Ouellette
The chassis, constructed by a satellite company called Maxar Technologies, was delivered last April. It’s roughly the size of a passenger van and was built largely from commercial, off-the-shelf technology. “Once in space, the spacecraft will use an innovative means of propulsion, known as Hall thrusters, to reach the asteroid,” Ars Senior Space Editor Eric Berger wrote last year. “This will be the first time a spacecraft has ventured into deep space using Hall thrusters, and absent this technology, the Psyche mission probably wouldn’t be happening—certainly not at its cost of just less than $1 billion.” Here’s a bit more from Berger about this innovative approach:
Engines powered by chemical propulsion are great for getting rockets off the surface of the Earth when you need a brawny burst of energy to break out of the planet’s gravitational well. But chemical rocket engines are not the most fuel-efficient machines in the world, as they guzzle propellant. And once a spacecraft is in space, there are more fuel-efficient means of moving around. NASA has been experimenting with [solar electric propulsion] technology for a while. The space agency first tested electric propulsion technology in its Deep Space 1 mission, which launched in 1998, and later in the Dawn mission in 2007 that visited Vesta and Ceres in the asteroid belt.
These spacecraft used ion thrusters. Hall thrusters, by contrast, use a simpler design, with a magnetic field to confine the flow of propellant. These thrusters were invented in the Soviet Union and later adapted for commercial purposes by Maxar and other companies. Many of the largest communications satellites in geostationary orbit today, such as those delivering DirecTV, use Hall thrusters for station-keeping.
Using Hall thruster-based technology enabled the mission’s scientists and engineers to design a smaller and more affordable spacecraft. Each of the Hall thrusters on Psyche will generate three times as much thrust as the ion thrusters on the Dawn spacecraft and can process twice as much power. This will allow the spacecraft to reach the Psyche asteroid, located in the main belt, in January 2026, after a 3.5-year journey.
The Psyche team tested the twin solar arrays in March, attaching the arrays to the spacecraft body and unfolding them lengthwise, before stowing the panels until the August launch. The five-panel, cross-shaped solar arrays are the largest installed at JPL, measuring 800 square feet (75 square meters). They are specially designed to work in low-light conditions, far away from the Sun.
Enlarge/ One of two solar arrays on NASA’s Psyche spacecraft was successfully deployed in JPL’s storied High Bay 2 clean room in March. The twin arrays will power the spacecraft and its science instruments during the mission.
NASA/JPL-Caltech
After launching from NASA’s Kennedy Space Center in August, the Psyche spacecraft will plug along on its Hall thrusters until it reaches Mars in May 2023. Then it will slingshot around the red planet for a gravitational assist for the final leg of the journey to its namesake asteroid.
“The most important thing is to get the engine and thrusters going right away,” JPL’s Henry Stone, Psyche project manager, told Ars. “This is not a chemical propulsion, this is an electrical propulsion mission. That means we are powering the vehicle, propulsing all the way to Psyche, in addition to doing a gravitational assist around Mars. We need to launch the vehicle, get it into a safe state quickly, and be prepared to get the engines up and running so that we can get to the final destination.”
Once everything is up and running, testing will begin on a laser communications experiment called Deep Space Optical Communications (DSOC), which will operate for about a year. The objective of this optical system is to improve the performance of spacecraft communications substantially over conventional radio frequency (rf) systems, similar to how fiber optic cables replaced old-school telephone wires.
Enlarge/ Your intrepid Ars correspondent in full clean room gear.
Jennifer Ouellette
“There’s a huge bandwidth crunch,” JPL’s Abhijit “Abi” Biswas, DSOC project technologist, told Ars. “We’re running out of bandwidth because of demand from near-Earth satellites. Moving to optical opens up a nice slice of spectrum. You get much higher data rates than rf— roughly a factor of 10 for large distances—all for the same mass and power, once we work out all the kinks. We have targeted data rates at targeted distances so if we can hit those data rates, then definitely it’s worked.”
DSOC boasts a flight laser transceiver, a ground laser transmitter, and a ground laser receiver. The experiment on board the Psyche spacecraft is a proof of principle. Substantial infrastructure on the ground would need to be developed for similar optical systems to be deployed in future missions. “There has to be some investment in that because, for deep space, you need large aperture ground collectors which don’t exist today,” Biswas said.
For the Psyche technology demonstration, Biswas’ team is relying on the near-infrared laser transmitter at JPL’s Table Mountain facility, with the Hale Telescope at California’s Palomar Observatory serving as a receiver. But that won’t be operationally feasible for broad deployment on future deep space missions, such as a manned mission to Mars. According to Biswas, JPL is currently experimenting with putting mirrors on the Goldstone antennas in hopes of using the same infrastructure to operate in both the optical and rf regimes.
Enlarge/ Underneath all that clean room gear is Linda Elkins-Tanton of Arizona State University (right), Psyche principal investigator, chatting with a reporter in front of the actual spacecraft.
NASA/JPL-Caltech
The spacecraft will reach the asteroid in January 2026 and spend the next 21 months in orbit mapping the body and measuring its properties. There will be three orbital stages, as the spacecraft gradually dips into successively lower orbits until it is orbiting just 53 miles (85 kilometers) above the surface.
Because the asteroid Psyche has such an odd shape, the mission scientists expect it most likely has a very irregular gravitational field. “We had to design the spacecraft in such a way to be able to account for that from a navigation and control standpoint,” said Stone. “That’s in part why we start out at a very high altitude, so we can safely orbit far away, and make measurements of the gravitational field. Then we can build that model and refine it in real time, so that we then know how to drop down successively these closer and closer orbits.”
And then we wait for all that data to be analyzed so Psyche can reveal its secrets. “My secret hope is that Psyche is not part of a metal core, that it’s something quite unusual,” Elkins-Tanton said. “I would love for it to be ‘reduced’: Some material that had all its oxygen stripped off it so that the metal is made up of the iron that’s left behind. Some previously undetected building block of planets, something we haven’t seen in the meteorite collection. That would be the biggest thrill to me.”
Enlarge/ “High Bay Bob” is an unofficial mascot of the High Bay clean rooms at JPL.
More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.
That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.
“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”
The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.
Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.
Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.
Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.
Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.
Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.
“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”
The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.
North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.
Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”
Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.
Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.
For Dello, the “fingerprints of climate change” were clear.
“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”
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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.
On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.
They call it “Big Sam.”
The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.
It didn’t die alone.
“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.
She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”
“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.
The head alone, she said, is about the size of a baby elephant.
The discovery was a long time coming.
The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.
“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.
When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”
“It contains about 100 to 300 bones per square metre,” she said.
Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.
About a year ago, they found the second adult: Big Sam.
Bamforth said both dinosaurs are believed to have been the elders in the herd.
“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.
“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”
The genders of the two adults are unknown.
Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.
The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.
She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.
“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.
“It’s pretty exciting.”
This report by The Canadian Press was first published Sept. 25, 2024.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
