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NASA Is Dropping a New Rover on Mars. Here’s What Could Go Wrong – Gizmodo

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Depiction of the Perseverance landing, with the rover still attached to backshell and retro-rockets engaged for powered descent.
Illustration: NASA/JPL-Caltech

Failure could take on many forms next week when NASA’s next-gen rover, Perseverance, reaches the surface of the Red Planet. Here’s what needs to go right—and how things could quickly go sideways—when Perseverance tries to make its much-anticipated landing.

For NASA, the entry, descent, and landing (EDL) of Perseverance on Thursday, February 18 presents numerous potential points of failure. NASA has said that “hundreds of things have to go just right” for the rover to survive the seven minutes of terror. We can’t take a safe landing for granted: As NASA points out, only “about 40 percent of the missions ever sent to Mars—by any space agency—have been successful.” Which, yikes.

In a nutshell, Perseverance will have to transition from speeds reaching 12,500 miles per hour (20,000 km/hr) to a walking pace over the course of several minutes. What’s more, it’ll have to perform this autonomously, as it takes nearly 11 minutes for radio signals to reach Earth. To complicate matters, NASA is debuting two new technologies for the mission, both relating to the EDL phase and both unproven.

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All three phases—entry, descent, and landing—present their own unique challenges.

Graphic showing the various stages of the upcoming landing.

Graphic showing the various stages of the upcoming landing.
Graphic: NASA/JPL-Caltech

The rover, nestled inside the descent stage, will separate from the cruise stage, which, with its solar panels, radios, and fuel tanks, will no longer be required. Next, the spacecraft will have to orient itself such that its heat shield is facing forward, a task made possible by small thrusters located on the backshell. During atmospheric entry, the spacecraft’s heat shield will need to endure temperatures reaching 2,370 degrees Fahrenheit (1,300 degrees Celsius). A structural failure at this stage would be catastrophic, ending the mission before it has a chance to get started.

Indeed, previous missions to the Red Planet have failed right at the Martian doorstep. In 1999, NASA’s Mars Climate Orbiter entered into an orbit that was way too low, causing the spacecraft to burn up in the atmosphere. The failure was eventually traced to a conversion error, in which imperial units of pound-seconds were not converted to the standard metric Newton-seconds. Hate it when that happens.

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Should the descent stage survive atmospheric entry, it will still have to contend with variably dense air pockets that could steer it off course. A guided entry will be performed to avoid this problem, in which the descent stage will fire small thrusters to compensate.

Graphic comparing the size of the Curiosity rover’s landing ellipse (blue) with Perseverance’s landing ellipse (red).

Graphic comparing the size of the Curiosity rover’s landing ellipse (blue) with Perseverance’s landing ellipse (red).
Graphic: NASA/JPL-Caltech

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The unfurling of the 70-foot-wide (21.5-meter) parachute is next. Should the parachute unfurl properly and not get tangled, the descent stage will abruptly decelerate to 1,000 miles per hour (1,600 km/h), which is still blazingly fast (remember, Mars has a super thin atmosphere). The deployment of this supersonic parachute will depend on an unproven new technology called Range Trigger, which will calculate the distance to the landing spot and trigger the parachute to deploy at just the right moment. This is expected to happen approximately 240 seconds after atmospheric entry, when the descent stage is about 7 miles (11 km) above the surface. Perseverance will bid farewell to its heat shield around 20 seconds after the parachute has unfurled, introducing another potential point of failure.

This is a critical stage—one with regrettable historical precedents. During the failed landing of ESA’s Schiaparelli mission in 2016, the descent stage prematurely ejected the parachute and heat shield, the result of a software glitch. An onboard computer thought it was just a few feet off the ground, but in reality the descent stage was somewhere between 1.25 and 2.5 miles (2-4 km) above the surface. You can imagine what happened next. The doomed Schiaparelli lander was traveling at around 185 miles per hour (300 km/h) when it smashed into the Martian regolith.

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Graphic showing how the terrain-relative navigation system will work.

Graphic showing how the terrain-relative navigation system will work.
Graphic: NASA/JPL-Caltech

With the heat shield gone, and with the rover now finally exposed to the Martian atmosphere, another new technology will kick in, called Terrain-Relative Navigation. The proper execution of this tool will be critical, as the chosen landing spot, a crater, is quite dangerous.

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“Jezero is 28 miles wide, but within that expanse there are a lot of potential hazards the rover could encounter: hills, rock fields, dunes, the walls of the crater itself, to name just a few,” Andrew Johnson, principal robotics systems engineer at NASA’s Jet Propulsion Laboratory, said in a press release. “So, if you land on one of those hazards, it could be catastrophic to the whole mission.”

Here’s how NASA describes the new tool, which should allow the landing craft to determine its position relative to the surface with a degree of accuracy close to around 130 feet (40 meters) or less.

Terrain-Relative Navigation lets the rover make much more accurate estimates of its position relative to the ground during descent. […] Using images from Mars orbiters, the mission team creates a map of the landing site. The rover stores this map in its new computer “brain,” designed specifically to support Terrain-Relative Navigation. Descending on its parachute, the rover takes pictures of the fast-approaching surface. To figure out where it’s headed, the rover quickly compares the landmarks it sees in the images to its onboard map. Armed with the knowledge of where it’s headed, the rover searches another onboard map of safe landing zones to find the safest place it can reach. The rover can avoid dangerous ground up to about 1,100 feet (335 meters) in diameter (about the size of three football fields end-to-end), by diverting itself toward safer ground.

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The parachute should slow the descent stage down to about 200 miles per hour (320 km/h), requiring one last step for slow down: powered descent with eight tiny retro-rockets. After ditching the parachute, the rover, still attached to its backshell, will cruise toward the surface from an initial height of 6,900 feet (2,100 meters).

Depiction of the skycrane maneuver.

Depiction of the skycrane maneuver.
Illustration: NASA/JPL-Caltech

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Some 12 seconds prior to touchdown, and at the very reasonable speed of 1.7 miles per hour (2.7 km/hr), it’ll be time for the skycrane maneuver. The backshell will lower the rover using three 66-foot-long (20-meter) cables, during which time the rover’s legs and wheels will move into their landing position. Perseverance, sensing an imminent landing, will let go of the cables, and the descent stage will zip off and crash—hopefully—far away.

Lots of moving parts, including some projectiles, obviously make this an extraordinarily complicated dance. The heat shield, parachute, and backshell all risk damaging or otherwise interfering with the landing and/or the performance of Perseverance.

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Again, history provides another example of a mission failing at this point, namely NASA’s Mars Polar Lander, which, like the Mars Climate Orbiter, died in 1999 (not a great year for NASA). According to NASA, the “most probable cause of the failure was the generation of spurious signals when the lander’s legs deployed during the descent,” which “falsely indicated that the spacecraft had touched down on Mars when in fact it was still descending,” causing the “main engines [to] prematurely shut down,” resulting in the lander falling to the Martian surface.

Should anything go wrong during the landing, Swati Mohan will be among the first to know, as she’s the guidance, navigation, and control operations lead for the Mars 2020 mission. She’ll be at NASA mission control tracking the progress and health of the rover during the landing.

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“Real life can always throw you curve balls. So, we’ll be monitoring everything during the cruise phase, checking power to the camera, making sure the data is flowing as expected,” said Mohan in a press release. “And once we get that signal from the rover that says, ‘I’ve landed and I’m on stable ground,’ then we can celebrate.”

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The rover, though modeled on Curiosity, has many new features, including an array of cameras and the ability to peer beneath the surface with ground-penetrating radar. The rover will land at Jezero crater, where it will search for signs of ancient life. If life once existed on Mars, a spot like Jezero crater—a former lake and river delta—would’ve been an ideal place for microbes to hang out. In addition to this important astrobiological work, Perseverance will also study Martian weather and geology, deploy a small helicopter named Ingenuity, and collect samples for a future mission.

NASA will have a live stream of coverage of the landing, which is scheduled for February 18 at 3:30 p.m. ET (12:30 p.m. PT). We’ll be watching and hoping for the best.

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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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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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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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.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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