Planetary scientists now know how thick the Martian crust is, thanks to the strongest Marsquake ever observed.

On average, the crust is between 42 and 56 kilometers thick, researchers report in a paper to appear in Geophysical Research Letters. That’s roughly 70 percent thicker than the average continental crust on Earth.

The measurement was based on data from NASA’s InSight lander, a stationary seismometer that recorded waves rippling through Mars’ interior for four Earth years. Last May, the entire planet shook with a magnitude 4.7 quake that lasted more than six hours (SN: 5/13/22). “We were really fortunate that we got this quake,” says seismologist Doyeon Kim of ETH Zurich.
InSight recorded seismic waves from the quake that circled Mars up to three times. That let Kim and colleagues infer the crust thickness over the whole planet.

Not only is the crust thicker than that of the Earth and the moon, but it’s also inconsistent across the Red Planet, the team found. And that might explain a known north-south elevation difference on Mars.

Topological and gravity data from Mars orbiters have shown that the planet’s northern hemisphere is substantially lower than the southern one. Researchers had suspected that density might play a part: Perhaps the rocks that make up northern Mars have a different density than those of southern Mars.

But the crust is thinner in the northern hemisphere, Kim and colleagues found, so the rocks in both hemispheres probably have the same average densities. That finding helps scientists narrow down the explanations for why the difference exists in the first place.

Knowing the crust’s depth, the team also calculated that much of Mars’ internal heat probably originates in the crust. Most of this heat comes from radioactive elements such as potassium, uranium and thorium. An estimated 50 to 70 percent of those elements are probably in the crust rather than the underlying mantle, computer simulations suggest. That supports the idea that parts of Mars still have volcanic activity, contrary to a long-held belief that the Red Planet is dead (SN: 11/3/22).

Former Raiders receiver Henry Ruggs III has been ordered to appear in Las Vegas court on Monday following a missed alcohol test. That is a violation of his bond release restrictions following a fatal crash in which prosecutors say he was driving under the influence at 156 mph.

According to Clarke County court records, Ruggs missed one of four daily court-mandated alcohol tests at 4:41 p.m. local time on Saturday before completing "a client initiated remote breath test" at 6:28 p.m. the same day. The alcohol monitoring agency noted in court filings that it couldn't verify Ruggs' sobriety at the time he was supposed to complete his test earlier in the day.
Ruggs' attorney David Chesnoff told Judge Suzan Baucum — who has ordered his reappearance in court — that the delay in his test was related to trouble with equipment provided to him. Ruggs, 22, could face a return to jail for violating the terms of his release. Ruggs was released on $150,000 bond on Wednesday, Nov. 3 and was ordered to remain on house arrest while undergoing electronic surveillance. He is also to refrain from alcohol or other controlled substances, among other restrictions.

Ruggs was arrested after his involvement in a fatal drunk-driving accident on Tuesday, Nov. 2. Prosecutors said he was driving 156 mph at the time of the crash, with a blood alcohol content level of .16 — twice the legal limit for Nevada drivers. Ruggs' Chevrolet Corvette struck the back of 23-year-old Tina Tintor's Toyota Rav4. Witnesses to the event indicated they tried to help Tintor and her dog escape the vehicle, but were ultimately forced back from flames emanating from the car.
Ruggs faces two felony charges of DUI resulting in death or serious injury. That is considered a category B felony in Nevada, the second-worst violation of state law. The charges are non-probationary, meaning Ruggs will face jail time if convicted. Each charge carries a minimum two-year sentence, but can go as long as 20 years. He also faces two counts of felony reckless driving — charges with penalties of one to six years in prison — and a misdemeanor weapon charge.

The Raiders released Ruggs on Nov. 2 following his DUI arrest. He was the No. 12 overall pick in the 2020 NFL Draft, and the highest receiver taken in the draft.