Category Astronomy/Space

The further we move away from a heat source, the cooler the air gets. Bizarrely, the same can’t be said for the Sun, but University of Otago scientists may have just explained a key part of why.

Study lead Dr Jonathan Squire, of the Department of Physics, says the surface of the Sun starts at 6000 degree C, but over a short distance of only a few hundred kilometers, it suddenly heats up to more than a million degrees, becoming its atmosphere, or corona.

“This is so hot that the gas escapes the Sun’s gravity as ‘solar wind’, and flies into space, smashing into Earth and other planets.

“We know from measurements and theory that the sudden temperature ju...

Researchers have built the world’s first physics-based computer simulation of oxygen transport on Europa, finding that it’s possible for oxygen to drain through the moon’s icy shell and into its ocean of liquid water — where it could potentially help sustain alien life — by hitching a ride on salt water under the moon’s ‘chaos terrains.’ The results show that not only is the transport possible, but that the amount of oxygen brought into Europa’s ocean could be on a par with the quantity of oxygen in Earth’s oceans today.

This theory has been proposed by others, but the researchers put it to the test by building the world’s first physics-based computer s...

Using data from ESA’s Gaia mission, astronomers have shown that a part of the Milky Way known as the ‘thick disc’ began forming 13 billion years ago, around 2 billion years earlier than expected, and just 0.8 billion years after the Big Bang.

This surprising result comes from an analysis performed by Maosheng Xiang and Hans-Walter Rix, from the Max-Planck Institute for Astronomy, Heidelberg, Germany. They took brightness and positional data from Gaia’s Early Data Release 3 (EDR3) dataset and combined it with measurements of the stars’ chemical compositions, as given by data from China’s Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) for roughly 250 000 stars to derive their ages.

They chose to look at sub giant stars...

Astronomers identified a nearby star whose sunspot cycles appear to have stopped. Studying this star might help explain the unusual period from the mid 1600s to the early 1700s when our Sun paused its sunspot cycles.

The number of sunspots on our Sun typically ebbs and flows in a predictable 11-year cycle, but one unusual 70-year period when sunspots were incredibly rare has mystified s...