Universe Is Expanding Faster Than We Thought
How fast is our universe expanding? Over the decades, there have been different estimates used and heated debates over those approximations, but now data from the Spitzer Space Telescope have provided the most precise measurement yet of the Hubble constant, or the rate at which our universe is stretching apart.
The result? The universe is getting bigger a little bit faster than previously thought.
The newly refined value for the Hubble constant is 74.3 plus or minus 2.1 kilometers per second per megaparsec. The best previous estimation came from a study from the Hubble Space Telescope, at 74.2 plus or minus 3.6 kilometers per second per megaparsec. A megaparsec is roughly 3 million light-years.
To make the new measurements, Spitzer scientists looked at pulsating stars called Cepheid variable stars, taking advantage of being able to observe them in long-wavelength infrared light. In addition, the findings were combined with previously published data from NASA’s Wilkinson Microwave Anisotropy Probe. The new determination brings the uncertainty down to 3 percent, a significant advance in accuracy for cosmological measurements, scientists say.