Enlarge / All galaxies have large amounts of gas that influence their star-formation rates. (credit: NASA, ESA, CSA, and J. Lee (NOIRLab))

Galaxies pass gas—in the case of galaxy NGC 4383, so much so that its gas outflow is 20,000 light-years across and more massive than 50 million Suns.

Yet even an outflow of this immensity was difficult to detect until now. Observing what these outflows are made of and how they are structured demands high-resolution instruments that can only see gas from galaxies that are relatively close, so information on them has been limited. Which is unfortunate, since gaseous outflows ejected from galaxies can tell us more about their star formation cycles.

The MAUVE (MUSE and ALMA Unveiling the Virgo Environment) program is now changing things. MAUVE’s mission is to understand how the outflows of galaxies in the Virgo cluster affect star formation. NGC 4383 stood out to astronomer Adam Watts, of the University of Australia and the International Centre for Radio Astronomy Research (ICRAR), and his team because its outflow is so enormous.

Enlarge (credit: NASA Goddard/ASU)

Our Moon may appear to shine peacefully in the night sky, but billions of years ago, it was given a facial by volcanic turmoil.

One question that has gone unanswered for decades is why there are more titanium-rich volcanic rocks, such as ilmenite, on the near side as opposed to the far side. Now a team of researchers at Arizona Lunar and Planetary Laboratory are proposing a possible explanation for that.

The lunar surface was once flooded by a bubbling magma ocean, and after the magma ocean had hardened, there was an enormous impact on the far side. Heat from this impact spread to the near side and made the crust unstable, causing sheets of heavier and denser minerals on the surface to gradually sink deep into the mantle. These melted again and were belched out by volcanoes. Lava from these eruptions (more of which happened on the near side) ended up in what are now titanium-rich flows of volcanic rock. In other words, the Moon’s old face vanished, only to resurface.

Enlarge / Artist impression of a glory on exoplanet WASP-76b. (credit: ESA)

Do rainbows exist on distant worlds? Many phenomena that happen on Earth—such as rain, hurricanes, and auroras—also occur on other planets in our Solar System if the conditions are right. Now we have evidence from outside our Solar System that one particularly strange exoplanet might even be displaying something close to a rainbow.

Appearing in the sky as a halo of colors, a phenomenon called a "glory" occurs when light hits clouds made up of a homogeneous substance in the form of spherical droplets. It might be the explanation for a mystery regarding observations of exoplanet WASP-76B. This planet, a scorching gas giant that experiences molten iron rain, has also been observed to have more light on its eastern terminator (a line used to separate the day side from the night side) than its western terminator. Why was there more light on one side of the planet?

After observing it with the CHEOPS space telescope, then combining that with previous observations from Hubble, Spitzer, and TESS, a team of researchers from ESA and the University of Bern in Switzerland now think that the most likely reason for the extra light is a glory.

Enlarge / Mayans built impressive structures and occasionally put interesting items in the construction fill. (credit: Dr. Jürgen Tenckhoff)

As civilizations evolve, so do the political regimes that govern them. But the transition from one era to another is not always quiet. Some ancient Mayan rulers made a very fiery public statement about who was in charge.

When archaeologists dug up the burned fragments of royal bodies and artifacts at the Mayan archaeological site of Ucanal in Guatemala, they realized they were looking at the last remnants of a fallen regime. There was no scorching on the walls of the structure they were found beneath. This could have only meant that the remains (which had already been in their tombs a hundred years) were consumed by flames in one place and buried in another. But why?

The team of archaeologists, led by Christina T. Halperin of the University of Montreal, think this was the doing of a new leader who wanted to annihilate all traces of the old regime. He couldn’t just burn them. He also had to bury them where they would be forgotten.