In this show, Professor Derek Ward-Thompson tells us about the early stages of star formation and Libby talks to Dr Jay Farihi about locating the remains of planets around white dwarfs. Dr Iain McDonald answers your far-out questions, we bring you the latest astronomical odds and ends and there is a round up your feedback since the last show.
Interview with Professor Derek Ward-Thompson
Professor Derek Ward-Thompson works on the earliest stages of star formation at Cardiff University. He speaks here on using ALMA to see through the layers of dust in the interstellar medium to reveal binary stars in the process of forming. He also explains why stars spin as a result of their formation, and talks about the unusuall case of a binary star system with stars spinning in different directions.
Interview with Dr Jay Farihi
Dr Jay Farihi, from the University of Leicester, is trying to answer the question: "What will planetary systems like ours look like when the central star becomes a white dwarf?" In this interview, Jay talks about his compelling evidence that contamination by heavier elements in white dwarfs is a result of rocky planetary debris, with perhaps as many as 20% of all white dwarfs contaminated in this way, and he discusses the implications this has for the proportion of stars which have terrestrial planetary systems like the Earth.
Ask an Astronomer
Libby Jones puts your far-out questions to Dr Iain McDonald:
- Our first question is from Bjornar Johansen, who says: "For two decades now I have been aware that the Big Bang theory is just a theory. What has happened to the other cosmological models?"
- In a similar vein, Nick Cook asks: "Does dark matter really exist or have we misunderstood gravity?"
- Finally, Susan Kelly asks us the simple question: "What exactly is heat?" And gets a lecture on infrared radiation and molecular vibration for her troubles.
Odds and Ends
Space Shuttle Discovery ended its 27-year career on 9th March when it safely touched down at 16:57 GMT (Greenwich Mean Time) at Kennedy Space Center, Florida. Discovery has spent a total of 365 days in space during 39 flights, and will undergo a month of decontamination before being put on display in a museum. Endeavour will be the next shuttle to retire, and its final launch is scheduled for 19th April. Atlantis, the last of the shuttles, will retire a few months later. After this, NASA astronauts will be transported to and from the ISS (International Space Station) using the Russian Soyuz rockets. Discovery's final mission lasted 12 days and delivered to the ISS a new store room and a humanoid robot called Robonaut 2 (also known as R2). Over the next year, R2 will be thoroughly tested to make sure that it incurred no damage during transport. It currently weighs 300 lbs (140 kg) and will be mounted on a pedestal in the ISS, awaiting leg attachments which should be shipped within the next year. R2's dexterity and humanoid form allow it to use the same tools as the astronauts.
NASA's Glory satellite unfortunately failed to detach from its Taurus rocket after being launched from Vandenberg Air Force Base in California. Intended to measure the Earth's energy balance from space, it instead ended up lost at sea.
The Panoramic Survey Telescope & Rapid Response System, or Pan-STARRS, is a wide-field telescope which observes the whole of the night sky looking for potentially dangerous asteroids. On the night of 29th January, the telescope set a new record by spotting 19 asteroids, the most found in a single night. This has led to some discussion regarding the classification of planets. One of the definitions of a planet as set by the International Astronomical Union states that a planet "has cleared the neighbourhood around its orbit". Some say this means that Earth should be demoted to the status of a dwarf planet, like Pluto, though what it really means is that our definition of a planet might need revision.
A number of news organisations reported the scientifically unfounded possibility that the earthquake in Japan could have been caused by a so-called 'supermoon', an event in which the Moon is closer to the Earth than usual. The proximity of the Moon varies during a month as its orbit is elliptical, but it also undergoes a similar variation due to the Sun's gravitational pull, and this month comes closer than it has done for 19 years. We get tides because the Moon's force is greater on the near side of the Earth than on the far side, and the difference is greater when the Moon is closer and when the Sun and Moon line up to pull in the same direction (causing the higher spring tides). These tidal forces also affect the solid part of the Earth. But the largest effect is that of the daily tides which occur due to the Earth's rotation - these have never been shown to correlate with the frequency or strength of large earthquakes, nor has the distance from the Earth to the Moon. The earthquake in Japan also occurred eight days before the Moon's perigee (point of closest approach), when it was only a little closer than it commonly gets. The Moon will, however, appear bigger than usual on 19th March, so that is a good time to look at it.
A space beer has been manufactured by an Australian brewing company. This stout, named "Vostok" after the spacecraft flown by Yuri Gagarin in 1961, has a stronger flavour to mitigate the loss of taste due to astronauts' taste-buds swelling in space, and a reduced carbon dioxide content to prevent gas expanding in your stomach in zero gravity.
We mentioned the Amateur Astronomers Association of New York in the show.
|Interview:||Professor Derek Ward-Thompson and Libby Jones|
|Interview:||Dr Jay Farihi and Libby Jones|
|Ask An Astronomer:||Dr Iain McDonald and Libby Jones|
|Presenters:||Scot Hickinbottom, Libby Jones, Mark Purver and Christina Smith|
|Segment voice:||Lizette Ramirez|
|Website:||Stuart Lowe and Mark Purver|
|Cover art:||Computer simulation of the formation of a binary star system in the early Universe. Credit: Copyright Matt Turk and Ralph Kaehler|