Month: September 2022

Enlarge / One of the last images from DART. (credit: NASA/APL)

About 24 hours prior to its collision, NASA's Double Asteroid Redirect Test (DART) probe performed its last course correction based on commands sent by ground controllers. "It's pointed to within a football field of the central body," said Bobby Braun of the Johns Hopkins Applied Physics Lab (APL). "That last maneuver was spot-on."

Even at this late stage, DART's onboard camera couldn't resolve its ultimate target, the small asteroid Dimorphos, so the central body it was targeting is the partner Dimorphos orbits, called Didymos. DART's onboard navigation couldn't start navigating toward its target until it could see it, which was only expected to occur about 90 minutes before impact. At that point, the navigation started adjusting DART's course to get it heading straight at Dimorphos. Ground controllers, separated by about a minute of communications time, could only watch.

"Space is full of moments, and we're going to have a moment tonight, hopefully," said Braun.

Enlarge (credit: Bloomberg / Contributor | Bloomberg)

This month, LinkedIn researchers revealed in Science that the company spent five years quietly researching more than 20 million users. By tweaking the professional networking platform's algorithm, researchers were trying to determine through A/B testing whether users end up with more job opportunities when they connect with known acquaintances or complete strangers.

To weigh the strength of connections between users as weak or strong, acquaintance or stranger, the researchers analyzed factors like the number of messages they sent back and forth or the number of mutual friends they shared, gauging how these factors changed over time after connecting on the social media platform. The researchers' discovery confirmed what they describe in the study as "one of the most influential social theories of the past century" about job mobility: The weaker the ties users have, the better the job mobility. While LinkedIn says these results will lead to changes in the algorithm to recommend more relevant connections to job searchers as "People You May Know" (PYMK) moving forward, The New York Times reported that ethics experts said the study "raised questions about industry transparency and research oversight."

Among experts' biggest concerns was that none of those millions of users LinkedIn analyzed were directly informed they were participating in the study—which "could have affected some people's livelihoods," NYT's report suggested.