Scientists found a way to explain bird flocks that “defy” Newton’s third law - Science Daily

Gravity is best known as the force that pulls objects toward Earth, but its role extends far beyond falling apples. Across the universe, gravity acts as an invisible framework that influences how galaxies, galaxy clusters, and the largest cosmic structures form and evolve. For decades, however, astronomers have faced observations that do not seem to fit neatly with what can be seen. Some stars and galaxies move much faster than their visible mass appears capable of explaining. That mystery has led cosmologists such as University of Pennsylvania researcher Patricio A. Gallardo to investigate whether the laws of gravity established by Isaac Newton and Albert Einstein remain valid everywhere in the universe.

The biggest galaxy in the Deer Lick Group, galaxy NGC 7331 has lots to offer through a telescope, so track it down tonight. Looking for a sky event this week? Check out our full Sky This Week column.