In this show, Professor Martin Rees tells us about gamma-ray bursts and the future of humanity and two new work experience students ask doctor-in-waiting Adam Avison about the ALMA telescope. Dr Iain McDonald answers your astronomical questions, we report on some odds and ends from the universe of astronomy and there is a round up your feedback since the last show.
Interview with Professor Martin Rees
Professor Martin Rees is an emeritus professor of cosmology at the University of Cambridge. He has been active in astronomical research for over 45 years, and is the current Astronomer Royal as well as a member of the House of Lords. Professor Rees tells us about his long-standing interest in gamma-ray bursts, events so energetic that they can be seen across the visible Universe. Most of these are believed to come from supernovae at the ends of the lives of massive stars, so researchers use them to look back to the time of the first galaxies and to try to determine the epoch of reionisation, when the first stars began to shine. He also looks forward to the advent of the Square Kilometre Array, a radio telescope that will be able to detect the signal from distant cold hydrogen and pinpoint the time at which it became heated by that first generation of stars. These stars were not yet seeded with the heavy elements produced in supernovae, and existed in galaxies much smaller than those that surround us today. Professor Rees discusses the Swift satellite, which monitors the sky from optical to gamma-ray wavelengths in order to catch gamma-ray bursts and alert other observers before they fade away. He then goes on to talk about the popular books he has written, some on physics and others concerning the human race. He refers to Our Final Century, in which he argues that the problems and possibilities facing us in this century will shape the future of life on Earth as never before. He encourages everyone to think about how to manage the coming era when humans will control their own development as a species, when people may migrate away from the Earth and when humanity will have to act collectively in order to survive. He advocates awareness of the increasing pace of change in the World, and urges idealistic and able young people to consider working in politics in order to secure a future in which mankind flourishes and all people have a high standard of living.
Interview with Dr Adam Avison
Work experience students Lizzie Campbell and Ruth Wood interviewed our own Dr Adam Avison about his new job working for the UK ALMA Regional Centre, the UK hub for all things related to the Atacama Large Millimeter/submillimeter Array. Adam reveals how ALMA will provide an unprecedented insight into the Universe at millimetre wavelengths (high radio and microwave frequencies) and what interesting things it will look at. He also explains how an interferometer such as ALMA can be used to make images.
Ask an Astronomer
Libby Jones puts your astronomical questions to Dr Iain McDonald:
- Our first question comes from Philip Murphy, who asks: "If it takes 8 minutes for light to reach the Earth from the Sun (1 AU distance), and Saturn is approximately 9 AU away, does that mean that, if the Sun stop shining, Saturn would disappear 144 minutes (9x8x2) later for us? When would we stop seeing Venus: before, at the same time as, or after the Sun went out?"
- Artemi has sent us an e-mail, saying: "As far as I understand, astronomers are relatively confident about the parameters of the habitable zone around a star. Are the same parameters and relationships applicable to moons? Can a habitable moon exist around a planet that is outside its star's habitable zone?"
- We have also had a question from Chris Giltnane, who asks: "Is there any way of telling, from the radiation given off by the accretion disc around a black hole, whether that black hole is swallowing ordinary matter or dark matter?"
- Finally, very similar questions have been posed by MarkC, iam and Lydnen Baldwin, who all want to know: "What is space expanding into?" and: "If the Universe is expanding at an accelerating rate, what is the maximum speed it can attain?"
Odds and Ends
NASA's Kepler mission announced its latest exoplanet discoveries, including a system containing six planets orbiting their host star. The mission has now identified 15 planets and 1,235 candidates which need reobservation. 5 of the candidates may be Earth-sized planets in the habitable zone. Kepler monitors about 150,000 stars, looking for periodic drops in light intensity that would indicate planets transiting across them. You can help the search by joining the Planet Hunters.
On Valentine's Day, the NASA spacecraft Stardust made a flyby of Comet Tempel 1, the comet visited by the Deep Impact mission. At closest approach, the spacecraft was just 178 metres from the comet's surface. It returned images of Tempel 1, including pictures of the crater left by Deep Impact.
Another NASA mission, STEREO, provided the first-ever 360° snapshot of the Sun on the 6th of February. Its two spacecraft are in the Earth's orbital track on opposite sides of the Sun, and between them they can see almost the whole surface. Their complete view will allow coronal mass ejections and the solar wind to be better understood.
Scientists in Arizona have found that the dunes surrounding the north pole of Mars are not static as was originally thought. Repeated observations of the same dunes by HiRISE (High Resolution Imaging Science Experiment) on board the Mars Reconnaisance Orbiter have found that they change both gradually (such as by wind erosion) and by more sudden changes such as avalanches (often caused by the melting of the seasonal carbon dioxide ice).
The Channel Island of Sark could become the holiday destination of choice for amateur astronomers after being designated as the World's first 'dark sky island' by the International Dark-Sky Association. There are no street lights or private cars on the island, making objects such as the Milky Way and regular meteors easily visible.
If you are studying for GCSEs or A-levels and want to do work experience at the Jodrell Bank Centre for Astrophysics, have a look at this information page.
|Interview:||Professor Martin Rees and Mark Purver|
|Interview:||Dr Adam Avison, Lizzie Campbell and Ruth Wood|
|Ask An Astronomer:||Dr Iain McDonald and Libby Jones|
|Presenters:||Evan Keane, Cat McGuire, Mark Purver and Christina Smith|
|Editors:||Jen Gupta, Adam Avison, Melanie Gendre and Mark Purver|
|Segment voice:||Lizette Ramirez|
|Website:||Stuart Lowe and Mark Purver|
|Cover art:||An artist's conception of the star Kepler-11 and its six planets, with three transiting simultaneously. Credit: NASA/Tim Pyle|