In today’s Bulldog wrapup of tech, health and science news:

  • Spacecraft survives unprecedented trip between Saturn, rings
  • Uber self-driving car exec steps aside during Google lawsuit
  • Blood test offers hope for better lung cancer treatment
  • YouTube ad boycott could spell trouble for Alphabet’s Google

The details:

  • Spacecraft survives unprecedented trip between Saturn, rings

NASA’s Cassini spacecraft has survived an unprecedented trip between Saturn and its rings, and has amazing pictures to show for it.

Flight controllers regained contact with Cassini on Thursday, a day after it became the first craft to cross this hazardous region. The rings are made up of countless icy particles, any of which could have smacked Cassini. The spacecraft’s big dish antenna served as a shield as it hurtled through the narrow gap, temporarily cutting off communications.

“We are just ecstatic,” project science engineer Jo Pitesky said by phone from NASA’s Jet Propulsion Laboratory in Pasadena, California.

Cassini skimmed 1,900 miles (3,100 kilometers) above Saturn’s cloud tops, closer than ever before, and came within 200 miles (320 kilometers) of the innermost visible ring. Scientists say the pictures show details never seen before — there’s an incredible close-up, for instance, of the gigantic swirling hurricane at Saturn’s north pole.

After 13 years of Cassini orbiting the planet, “Saturn continues to surprise us,” Pitesky said.

Given their importance, data from the crossing are being sent to Earth twice, to make certain nothing is lost. It takes more than an hour for the signals to travel the approximately 1 billion miles (1.6 billion kilometers) between Saturn and Earth.

Twenty-one more crossings are planned — about one a week — before Cassini’s fatal plunge in mid-September.

  • Uber self-driving car exec steps aside during Google lawsuit

The executive running Uber’s self-driving car division is stepping aside while the company defends itself against charges that he provided the project with technology stolen from a Google spinoff.

Anthony Levandowski, an autonomous vehicle expert who defected from Google last year, notified Uber’s staff of his decision in a Thursday email. The change was made in tandem with Uber CEO Travis Kalanick, according to the email.

Although Levandowski will remain at Uber, he won’t be overseeing a crucial autonomous-car project while the ride-hailing service is locked in a legal showdown with Waymo, a rival started by Google eight years ago. Instead of reporting directly to Kalanick, Levandowski now will be under the supervision of a former subordinate, Eric Meyhofer, appointed to replace him during the Waymo battle.

Waymo filed a lawsuit in February accusing Levandowski of illegally downloading its blueprints for a navigation technology known as lidar before founding a startup that he later sold to Uber for $680 million.

That deal brought to Uber most of the employees now working in the company’s Advanced Technologies Group that’s building self-driving cars.

Waymo is seeking a court order that would force Uber to stop its work on autonomous vehicles on the grounds that the project has been drawing on trade secrets taken by Levandowski before he left Google.

  • Blood test offers hope for better lung cancer treatment

Researchers have taken an important step toward better lung cancer treatment by using blood tests to track genetic changes in tumors as they progress from their very earliest stages.

With experimental tests that detect bits of DNA that tumors shed into the blood, they were able to detect some recurrences of cancer up to a year before imaging scans could, giving a chance to try new therapy sooner.

It’s the latest development for tests called liquid biopsies, which analyze cancer using blood rather than tissue samples. Some doctors use these tests now to guide care for patients with advanced cancers, mostly in research settings. The new work is the first time tests like this have been used to monitor the evolution of lung tumors at an early stage, when there’s a much better chance of cure.

Only about one third of lung cancer cases in the United States are found at an early stage, and even fewer in other parts of the world. But more may be in the future as a result of screening of longtime smokers at high risk of the disease that started a few years ago in the U.S.

Early-stage cases are usually treated with surgery. Many patients get chemotherapy after that, but it helps relatively few of them.

  • YouTube ad boycott could spell trouble for Alphabet’s Google

YouTube’s inability to keep big-brand ads off unsavory videos is threatening to transform a rising star in Google’s digital family into a problem child.

It’s not yet clear whether a recent ad boycott of YouTube will be short-lived or the start of a long-term shift away from the video service — one that could undercut Google’s growth and that of its corporate parent, Alphabet Inc.

Alphabet’s first-quarter results, released Thursday, provided few clues. Major advertisers didn’t start pulling their money from YouTube until the three-month period was nearly over.

The company’s earnings rose 29 percent to $5.4 billion while revenue climbed 22 percent to $24.8 billion. Shares surged nearly 5 percent, to $933, in Thursday’s extended trading.

But the fallout from the YouTube boycott is likely to be felt through the rest of this year. Skittish advertisers have curtailed their spending until they are convinced Google can prevent their brands from appearing next to extremist clips promoting hate and violence.

“There is no entity in the world that is more risk averse than a senior marketing person,” says Larry Chiagouris, a marketing professor at Pace University in New York. “They don’t want to go with a media choice that presents problems for a brand, and they don’t have to because they have many other choices.”

Google CEO Sundar Pichai told analysts during a Thursday review of the first quarter that the company has had “thousands and thousands” of conversations with advertisers as YouTube takes steps to protect their brands. “We are evolving overall to a better place,” Pichai said.