This month sees the start of one mission and the end of another. NASA’s OSIRIS-REx mission launched at the start of the month to go and study asteroid Bennu, and even bring back a sample to Earth.
Meanwhile, the end of the month sees the finale of ESA’s Rosetta mission, which has spent two years studying comet 67P/Churyumov-Gerasimenko. With stunning images accompanied by fascinating results from other instruments, not to mention the plucky little Philae lander, Rossetta has been one of the most exciting missions of recent years.
This month, the Open University’s Professor Monica Grady tells me about comets, asteroids, and these two exciting missions.
Artist’s Impression of a Juno and Jupiter. Credit: NASA
In July 2016 NASA’s Juno spacecraft completed its five year journey to the planet Jupiter. On board is a suite of instruments and experiments that will provide exquisite insight into the history of our Solar System’s largest planet.
The process of Jupiter’s formation is a long-standing mystery that planetary scientists have been trying to answer for decades. As the University of Leicester’s Dr Leigh Fletcher explains, Juno will make careful measurements of Jupiter’s gravitational field and yield crucial information about its interior.
On 15th June 2016 the LIGO collaboration released more detections of gravitational waves. As with the first detection, announced back in February, these gravitational waves were emitted by pairs of black holes, spiralling together and merging,
But of course, those black holes need to come from somewhere, and in this case it’s thought to be the deaths of some of the most massive stars in the Universe. To understand more about the deaths of massive stars, and the formation of black holes, I talked to Professor Stephen Smartt, from Queen’s University Belfast, who’s been on the hunt for black holes.
This month’s focus is on two different stories, but both involving the same spacecraft: Kepler. Edward Gomez and I discuss a result from the outer edge of our Solar System, regarding the icy world that goes by the catchy name of “2007 OR10”. By combining information from the Kepler Spacecraft, now in the second phase of its mission with a partially-functioning spacecraft, with results from the Herschel Space Observatory, astronomers have made a new estimate of its size. Continue reading →
Earlier this week we heard the announcement of a new project from the “Breakthrough Initiatives”. The group is led by Yuri Milner, a Russian entrepreneur apparently named after Yuri Gagarin, along with Stephen Hawking and Mark Zuckerberg, and with support of an advisory panel of astronomers, theoretical physicists, space scientists, engineers and business leaders. The new initiative, Breakthrough Starshot, has the goal of sending a fleet of tiny spacecraft to the nearest star system. It gathered a fair bit of attention, at least for 24 hours—BBC Radio Wales even asked me to chat to them about it on Good Evening Wales. Continue reading →
March 2016 saw the launch of the first part of Europe’s two-part mission to Mars. The mission, called ExoMars, comprises the “Trace Gas Orbiter” – the part that’s just launched – and a large rover, which launches in 2018. The orbiter will sniff the atmosphere to test for evidence of past – or maybe even present – life. Elsewhere in the world of astronomy, this month has also seen the discovery a cluster of “monster stars”, and the most distant galaxy ever seen. I chatted to Edward Gomez and Tim Davis, a relatively new arrival here in Cardiff, about these discoveries.
It probably didn’t escape your notice that yesterday was 29th February – a date that comes round but once every 4 years. The reason for having leap years is explained in detail by Phil Plait on his Bad Astronomy blog (which is actually quite good). It’s essentially because the Earth’s rotation and the Earth’s orbit around the Sun aren’t quite in sync. Although a year is usually 365 days long, the Earth actually takes around 365.25 to get to the same place in space around its orbit. (It’s not exactly 365.25, and Phil Plait explains the details so I’ll defer to him.) Continue reading →
The gravitational waves detected by LIGO tend to be in the frequency range of a few tens of Hertz to a few hundred Hertz. That’s not just a coincidence – it’s the frequency that LIGO is designed to operate at, and that in turn is because that’s the frequency at which it’s expected that some of the most common relatively powerful gravitational wave sources in the sky occur at. It’s also a feature of the design of the instrument, with higher frequencies limited by the laser power (more photons = more sensitive) and lower frequencies limited by things like the seismic isolation, thermal variations in the mirrors and suspension, and a range of other things. If you are interested in finding out more, you should play Space Time Quest.
Because frequency range to which LIGO is sensitive is is within the human hearing range, it’s possible to convert the gravitational wave signals directly into sound. They’re often a bit low, so it’s common to shift them up in frequency – it can be that’s not really any different from shifting infrared data into the visible to make an image we can actually, well, see! The result, in the case of GW150914 (the first gravitational wave detection) is a sound like the one below. Continue reading →
Last week Patrick Sutton and I recorded an episode of BBC Science Cafe, a weekly BBC Radio Wales show hosted by Adam Walton. The show was broadcast earlier this evening, and you can listen to it here – at least for about a month after first broadcast (and probably only in the UK). Continue reading →