In the show this time, we talk to Dr Allison Kirkpatrick about the use of infrared in the detection of star forming regions in other galaxies, Josh Hayes rounds up the latest news, and we find out what we can see in the January night sky from Ian Morison and Claire Bretherton.
"That may have been one small step for Neil, but it's a heck of a leap for me." These are the words of Bruce McCandless, the first human to make an untethered space flight, who died on 21st December at the age of 80. McCandless was immortalised in what could be one of the most stunning photos ever taken when in 1984 he used a jetpack to fly, untethered, 100m away from the Space Shuttle Challenger. There were actually two Manned Manoeuvring Units (or MMUs) onboard the Challenger and with the help of his crewmate Robert Stewart, McCandless was the first to fly in both of them. He described the experience: "I was grossly overtrained. I was just anxious to get out there and fly... I'd been told of the quiet vacuum you experience in space, but with three radio links saying 'how's your oxygen holding out?', 'Stay away from the engines!', and 'When's my turn?' it wasn't that peaceful... It was a wonderful feeling, a mix of personal elation and professional pride: it had taken many years to get to that point."
In all the images of him during these flights, McCandless has his visor down so his face cannot be seen. Whilst this is due to him facing the Sun, in an interview with the Guardian in 2015, McCandles noted about the photo "It's also one of its main attractions: my anonymity means people can imagine themselves doing the same thing. Like Neil said in 1969, I was representing mankind up there." McCandless was more than just a guy in jet pack though. He actually helped design the MMUs, was part of the space shuttle crew which delivered the Hubble Space Telescope to orbit and was the mission control capsule communicator at Houston for the Apollo 11 mission, speaking to Neil Armstrong and Buzz Aldrin as they took their first steps onto the moon. All of us at the Jodcast would like to pay our respects to one of the great pioneers of space flight and pass on our condolences to his family.
Until the 14th December, the star Kepler-90 was known to host 7 planets, putting it just one planet off matching our own Sun. An AI built by Google discovered the faint signals of a transit by an 8th planet, placing Kepler-90 equal to the Sun in terms of the number of known planets it hosts. The AI was able to find a periodic dip in flux from the star which had been missed by human researchers and existing algorithms. This is an incredibly exciting leap forward in the use of machine learning techniques and identification algorithms in the fields of astronomy. Kepler-90 is slightly larger than the Sun, coming in at 1.2 times its mass and radius, and 6 of its planets are so called super-Earths, thought to be terrestrial, or mini-Neptunes, which straddle the line between terrestrial and ice giant. The other two planets are gas giants around the size of Jupiter.
There are several interesting things about this system. The planets are arranged similarly to our Solar System, with terrestrial planets closer to their host than the gas giants. This is currently the only other system where we have seen this, possibly due to selection biases with our detection methods where we are more likely to see so-called hot Jupiters. However, whilst Kepler-90's planets are arranged similarly to our own, they are much more closely packed. The entire system of 8 planets can fit inside the orbit of Earth, leading to them having particularly high temperatures. The discovery of this system is good news for planetary scientists, as it will allow us to further probe how large multi-planet systems form and evolve.
My mother always used to tell me not to pull faces in case the wind changed and I got stuck. On Jupiter, changing winds have been an even bigger problem, as until now we have had no explanation as to why Jupiter's jet stream changes direction around every 4 Earth years. Researchers using NASA's Infrared Telescope Facility (IRTF) in Hawaii may have worked out the mechanism behind the mystery - gravity waves.
Gravity waves are waves in a fluid which are generated by the gravity of a planet, for example, the waves the wind causes in our oceans. They should not be confused with gravitational waves, which are waves in space time and generated by the motion of massive bodies. The team have proposed that gravity waves are set up by convection low in the atmosphere of Jupiter and then rise up to the stratosphere. These waves then lead to the jet stream over the equator to change direction, an effect known as quasi-quadrennial oscillation, or QQO.
The measurements required to understand this process were made using the Texas Cross Echelle Spectrograph mounted on the IRTF. This instrument allowed for measurement of the motion of thin vertical strips of Jupiter's atmosphere which led to the current theory. Jupiter is not unique in exhibiting this phenomenon. Earth's jet stream changes direction about every 28 months and Saturn's changes around every 15 Earth years. Understanding how this process can occur, and the effects which it produces means that we can explore how atmospheres in a variety of planets behave, evolve and contribute to the features of the planet.
Interview with Dr Allison Kirkpatrick
Tom Scragg and Josh Hayes talk to Dr. Allison Kirkpatrick from Yale about the use of infrared in the detection of star forming regions in other galaxies.
The Night Sky
Ian Morison tells us what we can see in the northern hemisphere night sky during January 2018.
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during January 2018.
This month we will continue our tour of some of the clusters and nebulae along the Milky Way, which stretches across the eastern sky after dark, becoming brightest in the south towards the Southern Cross /Te Punga.
Wishing you clear skies, and a very happy 2018, form the team here at Space Place at Carter Observatory.
Odds and Ends
The European Southern Observatory recently announced that a new instrument had begun operations on the Very Large Telescope. The instument, which is called the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations or ESPRESSO, is a spectrometer designed to measure the slight velocity changes in stars caused by gravitational interactions with planets. The instrument is capable of detecting motions as small as a few centimetres per second; for reference, typical walking speeds are around 1.5 metres per second. Given this and the instrument's capability to work with the combined light from all four of the 8 metre telescopes at the VLT, ESPRESSO should lead to new breakthroughs in exoplanet science. More information is available from the press release on the ESO website.
We take a look at highlights of the upcoming year in space missions and the science they're expected to do. ISRO's Chandrayaan-2 and CNSA's Chang'e 4 are due to go to the Moon, and NASA is due to send InSight to Mars. BepiColombo, a joint ESA and JAXA mission, will hopefully find its way to Mercury with its two satellite components. ESA's Solar Orbiter and NASA's Parker Solar Probe will be launched to study the Sun, and TESS (the Transiting Exoplanet Survey Satellite) will continue to expand our exoplanet discoveries. Fingers crossed for punctual and successful launches!
On the 3rd of December WMAP team wins the breakthrough prize in fundamental physics for mapping the cosmic microwave background. We discuss the impact of their work, which lead to a deeper understanding of the origins of the universe. We also discuss the various science prizes on offer.
|Interview:||Dr. Allison Kirkpatrick and Tom Scragg and Josh Hayes|
|Night sky:||Ian Morison and Claire Bretherton|
|Presenters:||Emma Alexander, George Bendo, and Joel Williams|
|Editors:||Naomi Asabre Frimpong, George Bendo, Nialh McCallum, and Tom Scragg|
|Segment Voice:||Tess Jaffe|
|Website:||Josh Hayes and Stuart Lowe|
|Cover art:||WMAP CREDIT: NASA/WMAP Science team|