Enlarge / The cheapest version of Volvo's affordable EX30 is rear-wheel drive, but there's no reason to be afraid of that. (credit: Tim Stevens)

Rear-wheel drive cars long ago earned a reputation for being a bit of a nightmare to live with in snowy, icy conditions. That's partly why Volvo stopped making the things way back in the 1990s, so it was a surprise that the brand returned to rear-drive for its latest EVs, like its upcoming subcompact SUV, the EX30.

Why the throwback layout? Next-generation stability and traction-control systems, aided by the precise torque delivery of electric motors, allow for advanced modulation of power and braking that would have been impossible on those '90s icons. To see just how well Volvo's engineers succeeded at the task, I headed to northern Sweden to catch the tail of an Arctic winter and see whether this return to RWD was a success.

The driven wheel dilemma

Thanks to inertia, having the engine of a car drive the rear wheels actually provides the acceleration. When you accelerate, the car's mass effectively shifts rearward. That additional weight on the rear wheels gives them more grip—and gives you more speed.

Enlarge / The SOFIA telescope. (credit: Chris Johnson)

Welcome to the Daily Telescope . There is a little too much darkness in this world and not enough light, a little too much pseudoscience and not enough science. We'll let other publications offer you a daily horoscope. At Ars Technica, we're going to take a different route, finding inspiration from very real images of a universe that is filled with stars and wonder.

Good morning. It's April 1, and today's photo showcases an airplane—but it's a special airplane with some celestial treats in the background.

The plane is a shortened version of a Boeing 747 that housed the Stratospheric Observatory for Infrared Astronomy, known as SOFIA. This airborne observatory first took flight in May 2010 and operated through September 2022. The 2.5-meter telescope flew at about 45,000 feet and observed all manner of phenomena from a vantage point above much of the Earth's atmosphere—celestial magnetic fields, star-forming regions, comets, and more.

Enlarge / Malware Detected Warning Screen with abstract binary code 3d digital concept (credit: Getty Images)

On Friday, researchers revealed the discovery of a backdoor that was intentionally planted in xz Utils, an open-source data compression utility available on almost all installations of Linux and other Unix-like operating systems. The person or people behind this project likely spent years on it. They were likely very close to seeing the backdoor update merged into Debian and Red Hat, the two biggest distributions of Linux when an eagle-eyed software developer spotted something fishy.

"This might be the best executed supply chain attack we've seen described in the open, and it's a nightmare scenario: malicious, competent, authorized upstream in a widely used library," software and cryptography engineer Filippo Valsorda said of the effort, which came frightfully close to succeeding.

Researchers have spent the weekend gathering clues. Here's what we know so far.

Enlarge / The final Delta IV Heavy rocket is seen on the launch pad in Florida. (credit: United Launch Alliance)

Welcome to Edition 6.37 of the Rocket Report! The big story this week is the final launch of the Delta IV Heavy rocket, which is one of the biggest spectacles to enjoy lifting away from the planet. Because of a scrub on Thursday, there is still time to clear your calendar for a second attempt on Friday at 1:37 pm ET in Florida.

As always, we welcome reader submissions , and if you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Orbex patents reusable rocket tech . The British launch company said this week it has patented a "REFLIGHT" technology that enables the recovery of the first stage of its small Prime rocket. Essentially, Orbex designed an interstage that will function somewhat like grid fins on the Falcon 9 rocket's first stage. "After Stage 1 detaches from Stage 2, the interstage on top of Stage 1 reconfigures into four ‘petals’ which fold out and create drag forces that passively reorients and slows the spent rocket stage’s descent to Earth," the company stated.

Enlarge / NASA's and Lockheed Martin's X-59 experimental supersonic jet is unveiled during a ceremony in Palmdale, California, on January 12, 2024. (credit: Robyn Beck/AFP via Getty Images)

When Chuck Yeager reached Mach 1 on October 14, 1947, the entire frame of his Bell X-1 aircraft suddenly started to shake, and the controls went. A crew observing the flight in a van on the ground reported hearing something like a distant, rolling thunder. They were probably the first people on Earth to hear a boom made by a supersonic aircraft.

The boom felt like an innocent curiosity at first but soon turned into a nightmare. In no time, supersonic jets—F-100 Super Sabers, F-101 Voodoos, and B-58 Hustlers—came to Air Force bases across the US, and with them came the booms. Proper, panes-flying-off-the windows supersonic booms. People filed over 40,000 complaints about nuisance and property damage caused by booming jets, which eventually ended up with the Federal Aviation Administration imposing a Mach 1 speed limit for flights over land in 1973.

Now, NASA wants this ban to go. It has started the Quesst mission to go fast over American cities once more. But this time, it wants to do it quietly.

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  All the available Immersive Video launch content fit on a small strip in the TV app. [credit: Samuel Axon ]

Tonight, Apple will debut some new Immersive Video content for the Vision Pro headset—the first sports content for the device. It doesn't seem like much after two months of no new content, though.

Starting at 6 pm PT/9 pm ET, Vision Pro users will be able to watch a sports film captured for the platform's Immersive Video format. The video will be a series of highlights from last year's Major League Soccer (MLS) playoffs, and according to Six Colors , it will run just five minutes. It will be free for all Vision Pro users.

On February 2, Apple released what appeared to be the first episodes of three Immersive Video series: Adventure , Prehistoric Planet , and Wildlife . Each debuted alongside the Vision Pro's launch with one episode labeled "Episode 1" of "Season 1."

Enlarge (credit: LifeSpan )

I enjoy getting my exercise, but hate doing it indoors. I'd much rather get some fresh air and watch the world drift past me as I cycle or hike somewhere than watch a screen while sweating away on something stationary.

To get a bit more of what I like, I've invested in a variety of gear that has extended my cycling season deeper into the winter. But even with that, there are various conditions—near-freezing temperatures, heavy rains, Canada catching fire—that have kept me off the roads. So, a backup exercise plan has always been on my to-do list.

The company LifeSpan offers exercise equipment that fits well into a home office and gave me the chance to try its Ampera model . It's a stationary bike that tucks nicely under a standing desk and has a distinct twist: You can pedal to power the laptop you're working on. Overall, the hardware is well-designed, but some glitches, software issues, and design decisions keep it from living up to its potential.

Enlarge / A promotional image for Sorry for Your Loss , which was a Facebook Watch original scripted series. (credit: Facebook )

Last April, Meta revealed that it would no longer support original shows, like Jada Pinkett Smith's Red Table Talk talk show, on Facebook Watch. Meta's streaming business that was once viewed as competition for the likes of YouTube and Netflix is effectively dead now; Facebook doesn't produce original series, and Facebook Watch is no longer available as a video-streaming app.

The streaming business' demise has seemed related to cost cuts at Meta that have also included layoffs. However, recently unsealed court documents in an antitrust suit against Meta [ PDF ] claim that Meta has squashed its streaming dreams in order to appease one of its biggest ad customers: Netflix.

Facebook allegedly gave Netflix creepy privileges

As spotted via Gizmodo , a letter was filed on April 14 in relation to a class-action antitrust suit that was filed by Meta customers, accusing Meta of anti-competitive practices that harm social media competition and consumers. The letter, made public Saturday, asks a court to have Reed Hastings, Netflix's founder and former CEO, respond to a subpoena for documents that plaintiffs claim are relevant to the case. The original complaint filed in December 2020 [ PDF ] doesn’t mention Netflix beyond stating that Facebook “secretly signed Whitelist and Data sharing agreements” with Netflix, along with “dozens” of other third-party app developers. The case is still ongoing.

Enlarge / Scientists have found a large black hole that “hiccups,” giving off plumes of gas. (credit: Jose-Luis Olivares, MIT)

In December 2020, astronomers spotted an unusual burst of light in a galaxy roughly 848 million light-years away—a region with a supermassive black hole at the center that had been largely quiet until then. The energy of the burst mysteriously dipped about every 8.5 days before the black hole settled back down, akin to having a case of celestial hiccups.

Now scientists think they've figured out the reason for this unusual behavior. The supermassive black hole is orbited by a smaller black hole that periodically punches through the larger object's accretion disk during its travels, releasing a plume of gas. This suggests that black hole accretion disks might not be as uniform as astronomers thought, according to a new paper published in the journal Science Advances.

Co-author Dheeraj "DJ" Pasham of MIT's Kavli Institute for Astrophysics and Space research noticed the community alert that went out after the All Sky Automated Survey for SuperNovae (ASAS-SN) detected the flare, dubbed ASASSN-20qc. He was intrigued and still had some allotted time on the X-ray telescope, called NICER (the Neutron star Interior Composition Explorer) on board the International Space Station. He directed the telescope to the galaxy of interest and gathered about four months of data, after which the flare faded.