Category Astronomy/Space

Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called “impossible early galaxy problem.”

“Our newly-devised model stretches the galaxy formation time by a several billion years, making the universe 26.7 billion years old, and not 13.7 as previously estimated,” says author Rajendra Gupta, adjunct professor of physics in the Faculty of Science at the University of Ottawa.

For years, astronomers and physicists have calculated the age of our universe by measuring the time elapsed since the Big Bang and by studying the oldest stars based on the redshift of light coming from distant galaxies...

Rivers have flowed on two other worlds in the solar system besides Earth: Mars, where dry tracks and craters are all that’s left of ancient rivers and lakes, and Titan, Saturn’s largest moon, where rivers of liquid methane still flow today.

A new technique developed by MIT geologists allows scientists to see how intensely rivers used to flow on Mars, and how they currently flow on Titan. The method uses satellite observations to estimate the rate at which rivers move fluid and sediment downstream.

Applying their new technique, the MIT team calculated how fast and deep rivers were in certain regions on Mars more than 1 billion years ago...

The origin of Mercury, the closest planet to the sun, is mysterious in many ways. It has a metallic core, like Earth, but its core makes up a much larger fraction of its volume—85% compared to 15% for Earth.

The NASA Discovery-class MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) mission, and first spacecraft to orbit Mercury, captured measurements revealing that the planet also strongly differs chemically from Earth. Mercury has relatively less oxygen, indicating that it formed from different building blocks in the early solar system. However, it has proven difficult to precisely pin down Mercury’s oxidation state from available data.

In a new st...

Charged cosmic rays, high-energy clusters of particles moving through space, were first described in 1912 by physicist Victor Hess. Since their discovery, they have been the topic of numerous astrophysics studies aimed at better understanding their origin, acceleration and propagation through space, using satellite data or other experimental methods.

The Alpha Magnetic Spectrometer (AMS) collaboration, a large research group analyzing data collected by a large magnetic spectrometer in space, recently gathered new insight about the properties and composition of specific types of cosmic rays...