Tis the Season

1 December 2021

Tis the season for another newsletter. My gifts to you are five posts on astronomy.

Between the Moon and Stars

What is the difference between a moon and a planet? It seems pretty clear, unless you look at the history of the terms, as a recent study did. They found that the term moon is fairly recent, and even things such as the moons of Jupiter and Saturn were once called planets. Perhaps the term “worlds” would be more fitting?

Of course we might want to terraform some of these worlds in the future, and the first on the list is Mars. Terraforming Mars is a challenge because it has a weak magnetic field, but a new study shows how we might be able to give it a stronger one.

Through a Glass, Darkly

Dark matter is a seasonal favorite, and this month a study looked at how hyper-velocity stars might be used to map the distribution of dark matter in the Milky Way. One of the potential candidates for dark matter is a new type of neutrino known as the sterile neutrino. There hasn’t been much evidence for them in the past, but a new study is cautiously exciting. It will take further research to be sure.

One of the difficulties in studying neutrinos is that they interact via the weak force, which we don’t fully understand. A recent paper looks at how we might study the weak force through neutron decay. Neutron decay has been studied in the lab, but results are inconclusive. This new idea proposes looking at neutrons ejected from the surface of the Moon.

Start the Presses

In other news, I’ve finished writing a book recently: Radio Sky: 40 Years of the Very Large Array. It looks at the history of the VLA, and will be published by NRAO by the end of the year. I’ll have a link on my website when it becomes available.

As the year comes to a close, I hope you enjoy the holiday season. Here’s to 2022, and another year of science.