Llama. In the show this time, Prof. Valery Nakariakov talks to us about waves and oscillations in the Sun, Dr. Liz Guzman tells us about life at ALMA in a special guest JodBite all the way from the Atacama Desert and your astronomical questions are answered by Prof. Tim O'Brien in Ask an Astronomer.
JodBite with Dr. Liz Guzman
Ex-Jodcaster Dr. Liz Guzman talks to Indy about the ALMA (Atacama Large Millimeter/Submillimeter Array) project from the telescope site itself. ALMA is an array of more than 60 antennas situated on the Chajnantor plateau in the Atacama desert, 5000 meters above sea level. Liz talks us through her role as an ESO fellow in Chile, explains how the array works (and how to take observations using an interferometer) and describes an important early result with the data already taken.
Interview with Prof. Valery Nakariakov
Prof. Valery Nakariakov from the University of Warwick tells us about magnetohydrodynamic waves and oscillations in the solar corona. The Solar corona is a layer of plasma surrounding the Sun, part of the Solar atmosphere. Its temperature is millions of degrees higher than that of the surface of the sun, a phenomena known as the coronal heating problem. Within the plasma of the Solar corona, waves and oscillations exist, oscillating on time-scales of minutes to hours. This area of Solar physics is known as Coronal Seismology. These are regularly observed by telescopes such as the Solar Dynamic Observatory. By studying coronal seismology, we can learn a large amount about the dynamics and make-up of the corona, as well as potentially gaining insights into the coronal heating problem.
Ask an Astronomer
Prof. Tim O'Brien answers your astronomical questions:
- The first question is from Ted Thomas. He says 'When is a vacuum not a vacuum? In the space between the Sun and the Earth, we have electrons and protons, the solar wind. What density...would be required for photons to say, "This is not a vacuum; I have to travel slower."'.
- The next question is 'I was looking at APOD's image of NGC 2736, the pencil nebula. My question is, given the statistic about the speed it is moving and everything else, would we notice it if the Sun and Earth passed through the shock wave?'
- The third question is 'Does the CMB change in real time or is it a frozen moment? If we observe the CMB in a year's time do we see radiation that was released a year later than now or do we see the same thing but it is further away due to expansion of the universe? I assume that any changes would in reality be too small to detect with our resolution.'
- Final question for this month is from Lindsay Robertson who asks 'Why did the original singularity of the Big Bang not remain as a perfectly stable ultra-massive black hole, and what triggered the spectacular instability at one particular instant in time?'.
Odds and Ends
The Cygnus Spacecraft from Orbital Sciences Corp. successfully docked with the ISS on the 12th January. This is the first commercial re-supply of the ISS by Orbital Sciences and is part of a 6-resupply-mission contract with NASA. The Cygnus capsule carried a number of experiments, provisions, hardware and spareparts for the ISS as well as Christmas presents for the astronauts from their families and some fresh fruit from NASA.
High-quality pictures have been released from China's Chang'e-3 lunar lander and its Yutu (or 'Jade Rabbit') Moon rover. They show the first shots taken from the lunar surface in almost 40 years, as well as pictures from observational instruments, such as an extreme ultraviolet image of the Earth's plasmasphere.
Scientists at the recent American Astronomical Society (AAS) meeting have defined a new category of exoplanet, describing a type of planet that does not exist in our Solar System: so-called "mini-Neptunes" These planets are midway in size between Earth and Neptune, and are believed to be composed of a hard, rocky core surrounded by a thick envelope of hydrogen and helium gas.
As mentioned in the show, one of our listeners, Dennis Quinn, has produced a music track using pulsar recordings as the beat. Check it out here!
|JodBite:||Dr. Liz Guzman and Indy Leclercq|
|Interview:||Prof. Valery Nakariakov and Christina Smith|
|Ask An Astronomer:||Prof. Tim O'Brien and Indy Leclercq|
|Presenters:||Indy Leclercq, Mark Purver and Christina Smith|
|Editors:||Indy Leclercq, Tim O'Brien and Mark Purver|
|Segment Voice:||Iain McDonald|
|Website:||Indy Leclercq and Stuart Lowe|
|Cover art:||The Chinese Lunar Rover Yutu, or 'Jade Rabbit', trundles off into the distance on the surface of the Moon. CREDIT: Chinese Academy of Sciences/China National Space Administration|