Starts With a Bang! 31 Jul 2019, 14:01 UTC When you hold out your palm and point it towards the sky, what is it that’s interacting with your hand? You might correctly surmise that there are ions, electrons and molecules all colliding with your hand, as the atmosphere is simply unavoidable here on Earth. You might also remember that photons, or particles of light, must be striking you, too. But there’s something more striking your hand that, without relativity, simply wouldn’t be possible. Every second, approximately one muon — the unstable, heavy cousin of the electron — passes through your outstretched palm. These muons are made in the upper atmosphere, created by cosmic rays. With a mean lifetime of 2.2 microseconds, you might think the ~100+ km journey to your hand would be impossible. Yet relativity makes it so, and the palm of your hand can prove it. Here’s how.
Physics World Blog 31 Jul 2019, 11:30 UTC When we look up at the Moon from our Earthly vantage point, we see a familiar face of shadowed craters and bright ridges. But nowadays, with the aid of satellites and telescopes, we’re also able to look beyond that well-known visage and see our nearest neighbour in a different light. Sarah Tesh picks some of her favourite alternative views of the Moon.
astrobites 30 Jul 2019, 17:16 UTC Have you ever wondered what the first molecule that formed in the Universe was? As the temperature of the young Universe cooled to below 4000 K (or about 7000 °F), light elements produced during Big Bang nucleosynthesis began to recombine. As a result, the helium ions He2+ and He+ first recombined with free electrons to form neutral atoms. The recombination of hydrogen followed shortly thereafter, and in this metal-free and low-density environment, the stage was set for the formation of the first molecular bond in the Universe: the helium hydride ion HeH+. As recombination progressed, the eventual destruction of HeH+ created a path to the formation of molecular hydrogen, the most abundant molecule in the present Universe. Despite its importance in models of the chemical evolution of the early Universe, the HeH+ ion had never before been unambiguously detected in interstellar space. In today’s astrobite, we take a look at how astronomers found the first molecule molecule in the Universe and the implications for the origins of chemical complexity in the present Universe.
Bad Astronomy 30 Jul 2019, 13:00 UTC OK, I promise I'll explain all this, but I have to get this out of my system first: Astronomers have found that the Crab Nebula pulsar is blasting out extraordinarily high-energy photons by watching optical shock waves in water generated by faster-than-light muons. I know, right? Just writing that down was cool.
Universe Today 29 Jul 2019, 19:35 UTC The U.S. House of Representatives have passed a bill to change the name of the Large Synoptic Survey Telescope (LSST.) Instead of that explanatory yet cumbersome name, it will be named after American astronomer Vera Rubin. Rubin is well-known for her pioneering work in discovering dark matter.
Starts With a Bang! 29 Jul 2019, 14:01 UTC It’s not volcanic activity, and it’s definitely not from a fire.