In the show this time, Dr Paddy Leahy tells us about today's exciting new results from the Planck mission, Prof Richard Davis tells us about the Planck instruments and satellite in this month's JodBite, and your astronomical questions are answered by Dr Iain McDonald in Ask an Astronomer.
JodBite with Prof Richard Davis
Professor Richard Davis (University of Manchester) has been a lead scientist of the Low Frequency Instrument on board the Planck spacecraft. In this interview Richard talks about the operational success of the instruments aboard Planck and describes the receivers and bolometers that are used on the spacecraft (a previous interview with Professor Davis can be found here). These low-noise amplifiers were designed and produced at Jodrell Bank Observatory.
Interview with Dr Paddy Leahy
Dr Paddy Leahy works at the Jodrell Bank Centre for Astrophysics, and brings us headlines and analysis from the newly-released Planck results on which he is working. The Planck instrument has been making a detailed map of the sky at microwave frequencies since 2009, but only a general sky map had been published before now. In light of the new picture of the background radiation of our Universe, Paddy discusses what the cosmic microwave background is and why Planck has been used to measure it to greater accuracy than ever before. He reveals the vital statistics of our Universe as determined by Planck, including its age, rate of expansion and dark energy content. He also talks about what the results mean for current theories of cosmology and what further analysis of Planck data may tell us.
Ask an Astronomer
Dr Iain McDonald answers your astronomical questions:
- The first question comes from Mick Carling, who says: "My son Ben suddenly came out with "Dad, it is never a true full Moon because the Sun would have to be directly behind you and then the Moon would be in shadow". Thinking about it, I cannot fault his logic. Is it true?"
- The second question is from Henry Marston, who asks: "As the International Space Station interacts with the thin atmosphere where it orbits, it slows down and loses altitude. Every so often, rocket power has to be used to raise it to a higher orbit. On the other hand, the Moon is used to raise tides on Earth. Why does the Moon's move outwards, but artificial satellites move inward?"
- The final question this week is from John Bordelon who asks: "Watching for meteors, I notice several flashes in the sky. I have seen this in many locales many times while watching the night sky. These points of light do not return in the same spot. What I am seeing?"
Odds and Ends
NASA is switching on an experimental radar array for tracking near-Earth objects (NEOs) with better resolution than ever before. After some uncomfortably close passes to the Earth by asteroids in recent weeks, the aim is to calculate the orbital paths of NEOs to high accuracy, while also determining their sizes, shapes and compositions. It is hoped that a better knowledge of NEOs will help humanity to counter the threat of a collision in the future. Three 12-metre dishes, spaced 60 metres apart, will send out radio waves of around 30 GHz in frequency and collect their echoes, tracking NEOs as far as 1 AU (150 million km) from the Earth. In what might be regarded as a display of gallows humour, NASA has named the experiment the 'Ka-Band Objects Observation and Monitoring Project', or KaBOOM.
Astrophysics in the lab: Scientists from the University of Surrey have managed to mimic the behaviour of hydrogen in a white dwarf star , right here on Earth. The extreme conditions present in such a star, with a magnetic field of around 100,000 Tesla (1 trillion times as large as Earth's!) make it an extremely interesting object of study. The Surrey team managed to imitate this environment using silicon crystals laced with phosphorous atoms, effectively making "pretend" hydrogen made of one electron and one proton. Applying a field of 30 Tesla to the crystal then reproduced the spectrum seen in observations of white dwarfs. This discovery may soon lead to more exotic compounds being studied in the lab, as opposed to through a telescope!
ALMA observes the most distant galaxies ever observed before. The observations of these galaxies show us that stars were created of huge deposits of cosmic gas and dust. Also the main result showed that these galaxies have begun to form much earlier than previously thought.
|JodBite:||Prof Richard Davis and Libby Jones|
|Interview:||Dr Paddy Leahy and Mark Purver|
|Ask An Astronomer:||Dr Iain McDonald and Liz Guzman|
|Presenters:||Indy Leclercq, Liz Guzman, and Mark Purver|
|Editors:||Dan Thornton, Liz Guzman, and Mark Purver|
|Segment Voice:||Mike Peel|
|Website:||Mark Purver and Stuart Lowe|
|Cover art:||The newest map of the Cosmic Microwave Background Radiation (CMBR) by the Planck collaboration released on 21st March 2013 CREDIT: ESA and the Planck Collaboration|