Tuesday, 1 September 2009

Impact in the Media

The July 19th impact of an unknown body with Jupiter has created an unprecedented level of media interest.  It’s been extremely exciting to see our results flashed around the news wires, even as we race to understand the vast amounts of data we’re now acquiring from ground-based observatories all over the world.  Since the Infrared Telescope Facility results were first described (see my previous post), we were granted Directors Discretionary Time on the newly refurbished Hubble Space Telescope (see above), the twin Gemini telescopes (North and South) and the Very Large Telescope in Chile.  Each dataset provides a new piece of the puzzle, as we seek to understand both the origin and nature of the impactor itself, and the response of Jupiter’s gaseous atmosphere to such an extreme event.  Watch this space for our findings!

For now, I’ve collected together some of the more exciting media coverage of the Jupiter impact - enjoy!

Wednesday, 29 July 2009

The Lowdown on Jupiter's Black Eye

This post was originally written by my colleague, Glenn Orton, following the 2009 impact on Jupiter:
https://www.jpl.nasa.gov/blog/2009/7/the-lowdown-on-jupiters-black-eye

Image result for jupiter impact 2009 fletcher
Hubble Space Telescope view of the Wesley impact scar, four days after the collision.

We've had such great feedback and comments to our earlier post about the recent impact at Jupiter that we wanted to give you more details, plus answer some questions. My name is Glenn Orton, a senior research scientist at JPL. My colleague and fellow JPL blogger Leigh Fletcher is on a well-deserved vacation for a bit, and he filled in for me while I was at a conference talking about another aspect of our research and the Jupiter impact last week.

I've been on Anthony Wesley's email list (as I am for many in the amateur astronomy community) for some time, so it wasn't happenstance that I was aware of his Jupiter observation. Anthony is the Australian-based amateur astronomer who alerted the world to this big impact. When we received news of his discovery, we immediately wanted to verify it with some of the sophisticated telescopes NASA uses. Having actively observed in both the visible and infrared during the Shoemaker-Levy-9 impacts in 1994, I was aware that a quick verification was possible by looking at a wavelength with lots of gaseous absorption, which suppresses light reflected from Jupiter's deep clouds.

Luck was on our side. Several months before the impact, our JPL team had been awarded observing time on NASA's Infrared Telescope Facility (IRTF) atop Mauna Kea in Hawaii. We had the midnight to 6 a.m. shift (from our Pasadena office, which meant we started work at 3 a.m.) so much of our observing time would take place before Jupiter rose over Australian skies. Another piece of luck is that Anthony's "day job" involves software engineering so he was able to watch the same telescope instrument status and data screens as we were, while we did remote-style observing from the IRTF over the Internet. He would also be doing his own (now *very important*) post-impact observing. Weather was just as "iffy" over Mauna Kea as in Australia, so it was lucky for all of us that we could catch this event.

With Leigh, several JPL summer interns and me huddled at our side-by-side computers at JPL (one with instrument controls and one showing the data), and Anthony online from Australia, we got started. We knew the location of Anthony's dark spot would be coming over Jupiter's rising limb (edge) just as our allotted time was beginning. A near-infrared spectrometer was in the center of the telescope from the previous observer. Although it wasn't our instrument of choice (we wanted images!), it has a very nice guide camera sensitive to the near infrared, so we used it rather than waiting for the 20-40 minute hiatus needed by the telescope operator to move it out of the way and put our preferred instrument in its place. This turned out to be a good decision because the very first image showed us something brighter than anyplace else on the planet -- exactly where Anthony's dark feature was located. For me, this totally clinched the case that this was an impact. Even better was the fact that Anthony was looking on in real time. We e-mailed him what was obvious - he was *definitely* the father of a new impact!

Right after this we collected data that may help us sort out any exotic components of the impactor or of Jupiter's atmosphere and just how high the particulates have spread. Then we switched instruments to something at much longer wavelengths that told us the temperatures were higher, and that ammonia gas had probably been pushed up from Jupiter's troposphere (the lower part of the atmosphere) and ejected into its stratosphere (higher up in the atmosphere). We finished up with our preferred (more versatile) near-infrared camera and ended up, pretty tired, at 9 a.m. (this was a midnight to 6 a.m. run in Hawaii, and in California we were three hours ahead). Then we took some of the screen shots we'd been making and used them to submit a press release. Another person had already alerted a clearinghouse for important astronomical bulletins, so that was another thing that was important but that we didn't need to do.

Wednesday, 22 July 2009

All Eyes on Jupiter: The 2009 Impact

The text below is from a blogpost originally published while I was at JPL as a NASA Postdoc:
https://www.jpl.nasa.gov/blog/2009/7/all-eyes-on-jupiter

Image result for jupiter impact 2009 fletcher
These infrared images obtained from NASA's Infrared Telescope Facility in Mauna Kea, Hawaii, show particle debris in Jupiter's atmosphere after an object hurtled into the atmosphere on July 19, 2009. Image credit: NASA/IRTF/JPL-Caltech/University of Oxford

What an incredible few hours it's been for astronomers everywhere, as we witness a chance of a lifetime event: evidence of a space rock of some sort slamming into Jupiter. Images taken after the impact show the debris field and aftermath of a gigantic collision that occurred in the southern polar region of the enormous planet.

An extremely dedicated and meticulous team of amateur astronomers observe Jupiter's changing cloud patterns on a regular basis, and it came as an amazing surprise when Anthony Wesley, near Canberra, Australia, reported his Sunday-morning (July 19, 2009) observations (http://jupiter.samba.org/jupiter-impact.html) of a dark scar that bore all the hallmarks of the Shoemaker Levy 9 impacts at Jupiter in 1994. By an amazing coincidence, I was part of a team that had already been allocated time to observe Jupiter from the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. Based on Anthony's discovery, we were crowded around our computers at 3 a.m. PDT (with Anthony observing with us remotely from Australia) as the first near- and mid-infrared images started to come in... it was such an exciting moment, seeing the high altitude particles that had been lofted by the impact (they appear bright in the infrared). Anthony celebrated with us, but then the real work began. We celebrated and then rolled up our sleeves and began an exciting night of observations.

With the assistance of William Golisch at the IRTF, Glenn Orton and I viewed the impacts in as many wavelengths and spectra as we possibly could, as Jupiter rotated and carried the impact scar out of Earth's view. We used these many views to show evidence for high temperatures at the impact location, and suggestions of ammonia and aerosols that had been carried high into the atmosphere. The observations were repeated again today, Tuesday morning, to track the shape and properties of the site. The scar is extremely large, almost as big as Earth and will continue to grow as Jupiter's atmospheric winds and jet streams redistribute the material, and then, like Shoemaker-Levy 9, it will begin to fade in the coming weeks and months. Based on comparisons to SL-9, the impactor was likely to be small despite the large aftermath, maybe a few hundreds of metres across. Not only will this tell us a lot about impacts in the outer solar system, and how they contribute to the nature of the planets and icy moons, but they'll also serve as a probe for the fundamental weather patterns in Jupiter's high atmosphere.

Amateur observers continue to flood the Internet with new images of the dark spot at approximately 60 degrees south on Jupiter, and so far it looks as though the impact took place sometime in the 24 hours preceding Anthony's discovery. The debris field now extends out to the west and northwest, with additional high-resolution images from the Keck telescope (Marchis, Wong, Kalas, Fitzgerald and Graham http://keckobservatory.org/index.php/news/jupiters_adds_a_feature/) showing the detailed morphology of the impact region. The hard work continues today, as an international team of planetary astronomers scrambles for time on some of the world's largest astronomical facilities.

Finally, it's a shame but perhaps not surprising that we didn't see the collision, or the impactor itself, given the great distance to Jupiter. Like throwing a rock in a pond, we're seeing and analyzing the splash that it's made, and we can't yet infer many details about the rock itself - the detailed shape of the impact site could help determine the trajectory and energy of the collision. But it certainly made quite a splash, and we hope to learn a lot about Jupiter from this event!

Anthony's discovery is truly astounding, as it united astronomers in looking again at the gas giant Jupiter. It's overwhelming and spectacularly exciting to watch this event unfolding before our eyes!

Friday, 18 July 2008

Royal Astronomical Society Thesis Prize

Great news today from the Royal Astronomical Society, as I was awarded the Keith Runcorn Prize for ‘Best Doctoral Thesis in Astronomy and Geophysics’ for 2007 by the Royal Astronomical Society in London. 



From the JPL website newswire:

“Fletcher’s winning entry, “Saturn’s Atmosphere: Structure and Composition from Cassini/Composite Infrared Mapping Spectrometer,” was honoured for the best doctoral thesis in exploration geophysics; physics of Earth’s atmosphere, ionosphere or magnetosphere; planetary physics; solar physics; or solid-Earth geophysics.  Fletcher’s prize was administered by the society’s Higher Education Committee.”

A list of the previous prize winners can be found here.
           

Thursday, 3 January 2008

Hot Cyclones Churn at Both Ends of Saturn

Cassini thermal infrared observations in 2007 have revealed a surprise at Saturn’s north pole:  the first thermal observations of Saturn’s bizarre hexagonal wave (proving that the mechanism creating the hexagon perturbs the atmospheric temperature structure as well as the cloud patterns), and the detection of a small, localised tropospheric hotspot, sat right at Saturn’s north pole, despite 15 years of winter darkness.  We report our findings in today’s issue of Science, where we describe the symmetry in the dynamics governing Saturn’s winter and summer poles, and extrapolate these ideas to the other gas giants in our solar system.

The image shown above shows Saturn’s temperatures just below the tropopause (the temperature minimum), with the hexagon and the hotspot clearly defined by enhanced emission.  Surrounding the hotspot, you see Saturn’s typical belt/zone structure of alternating hot belts and cold zones, creating a ‘bulls-eye’ effect in this image.

The results were widely featured in the media, and some of the coverage is collected below.  I’ve also reprinted the original NASA/JPL press release which accompanied the story.

https://www.sciencemag.org/cgi/content/abstract/319/5859/79

Hot Cyclones Churn at Both Ends of Saturn
http://www.nasa.gov/mission_pages/cassini/media/cassini-20080103.html

False color image of Saturn's north pole This image shows newly discovered "hot spot" on Saturn's north pole and the mysterious hexagon that encircles the pole. The "hot spot" appears to be related to Saturn's dynamic weather systems, rather than to seasonal changes in the amount of sunlight at the pole.

Despite more than a decade of winter darkness, Saturn's north pole is home to an unexpected hot spot remarkably similar to one at the planet's sunny south pole. The source of its heat is a mystery. Now, the first detailed views of the gas giant's high latitudes from the Cassini spacecraft reveal a matched set of hot cyclonic vortices, one at each pole. Image credit: NASA/JPL/GSFC/Oxford University



While scientists already knew about the hot spot at Saturn's south pole from previous observations by the W. M. Keck Observatory in Hawaii, the north pole vortex was a surprise. The researchers report their findings in the Jan. 4 issue of Science.

"We had speculated that the south pole hot spot was connected to the southern, sunlit conditions," said Glenn Orton, a senior research scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and co-investigator on Cassini's composite infrared spectrometer. "Since the north pole has been deprived of sunlight since the arrival of winter in 1995, we didn't expect to find a similar feature there."

The infrared data show that the shadowed north pole vortex shares much the same structure and temperature as the one at the sunny south pole. The cores of both show a depletion of phosphine gas, an imbalance probably caused by air moving downward into the lowest part of Saturn's atmosphere, the troposphere. Both polar vortices appear to be long-lasting and intrinsic parts of Saturn and are not related to the amount of sunlight received by one pole or the other.

"The hot spots are the result of air moving polewards, being compressed and heated up as it descends over the poles into the depths of Saturn," said Leigh Fletcher, a planetary scientist from the University of Oxford, England, and the lead author of the Science paper. "The driving forces behind the motion, and indeed the global motion of Saturn's atmosphere, still need to be understood."

Though similar, the two polar regions differ in one striking way. At the north pole, the newly discovered vortex is framed by the distinctive, long-lived and still unexplained polar hexagon. This mysterious feature encompassing the entire north pole was first spotted in the 1980s by NASA's Voyager 1 and 2 spacecraft. Cassini's infrared cameras also detected the hexagon in deep atmospheric clouds early in 2007.

In their paper, Fletcher and his colleagues report that the bright, warm hexagon is much higher than previous studies had shown. "It extends right to the top of the troposphere," says Fletcher. "It is associated with downward motion in the troposphere, though the cause of the hexagonal structure requires further study."

Winter lasts about 15 years on Saturn. Researchers anticipate that when the seasons change in the coming years and Saturn's north pole is once again in sunlight, they will be able to see a swirling vortex with high eye walls and dark central clouds like the one now visible at the south pole. "But Saturn may surprise us again," says Fletcher.

"The fact that Neptune shows a similar south polar hot spot whets our appetite for the strange dynamics of the poles of the other gas giants," Fletcher says.

More information about Jupiter's poles will come from NASA's Juno mission, currently scheduled for launch in 2011 and arrival in 2016.

Fletcher's research was funded by the United Kingdom's Science and Technology Facilities Council.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. The science team for Cassini's composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md.

Oxford News Item:
http://www.ox.ac.uk/media/news_releases_for_journalists/080104.html

http://www.space.com/scienceastronomy/080103-saturn-spots.html


Monday, 26 March 2007

PM Hosts Reception for Inspiring Scientists

Along with more than 100 other scientists, I was invited to attend a Downing Street reception to mark the contribution that young scientists, engineers and researchers make to the UK's economy and quality of life.

Stood on the doorstep of 10 Downing Street before attending Tony Blair’s reception for young scientists.


From the press release:

“The PM told them that science was vitally important to the future of Britain, which should be a magnet for attracting the best people in the field.  The event, part of National Science and Engineering Week, celebrated those who inspire other young people to become the scientists of tomorrow - including science and engineering ambassadors. Other guests included those who have made breakthroughs in medicine, transport and new technology.”

The Prime Minister said: "Science is vitally important to the future of Britain. We have to be a magnet for scientific endeavour, attracting the best people and turning scientific knowledge into commercial enterprise. We need our young people today to embrace science and to realise that a career in science is an exciting prospect. These scientists provide the advice and practical examples to truly inspire.

Saturday, 3 March 2007

Voice of the Future 2007

I recently attended the Voice of the Future 2007 (VOF) event organised by the Royal Society of Chemistry at Portcullis House in London.

The event was designed to to enable dialogue between more than 200 young scientists, from A-level science students to postdocs and engineers, and members of parliament.  The main focuses of the event were an hour-long session with the Science Minister, Malcolm Wicks MP, followed by nearly two hours of questions answered by members of the Science & Technology Select Committee.

Also we had arranged beforehand to meet our local MPs Andrew Smith (Oxford East) and Dr Evan Harris (Oxford West and Abingdon and member of the select committee) which gave us the opportunity to address some issues face to face.

The Committee selected questions submitted by the audience during lunch and did their best to answer them - although in our opinion they seemingly hand-picked those which were relatively easy for them to discuss such as climate change and sustainable energy and scientific strategies to tackle them, nanotechnology, or if and how creationism should be taught in schools (as belief).

From the RSC Website:
http://www.rsc.org/AboutUs/News/PressReleases/2007/voiceofthefuture.asp

More than 200 young scientists and engineers from all over the UK attended the House of Commons to meet Science Minister Malcolm Wicks and members of the Science and Technology Select Committee (STSC).

The Voice of the Future Event, organised by the Royal Society of Chemistry's Parliamentary Affairs team, saw Mr Wicks give a speech which covered a number of important scientific issues, including climate change and the fight to improve healthcare on all frontiers.  Mr Wicks said: "This is a tremendously exciting time to be involved in scientific disciplines."  He was then asked a number of questions by the audience. One student asked why the government had sanctioned cuts to the research budget - to which Mr Wicks replied that his department (The Department for Trade and Industry) had to balance its books just like any other organisation. In this case, the cuts had been made to compensate for loss making projects such as those in the collapsed MG Rover.  Whilst the government was not happy to make the cuts, Mr Wicks described them as a blip, and said that the Labour Government had doubled science spending since coming to power.  Mr Wicks was also asked about the closure of Reading University's Physics Department, as well as renewable energy and energy security.

Back Row (from Left to Right) Mr. James Cottam (Oxford University), Mr. Ramin Lolachi (Oxford University), Dr. Evan Harris MP, Mr. Phil Willis (MP and Chair of Select Committee), Dr. Richard Pike (RSC Chief Executive) , Miss Anne Osterrieder (Oxford Brookes University), Dr. Imogen Sparkes (Oxford Brookes University), Dr. Brian Iddon MP, Dr. Stephen Benn (Parliamentary Advisor to the RSC).  Front Row (from Left to Right) Mr. Leigh Fletcher (Oxford University), Mr. Richard Branch (Oxford University), Dr. Carly Howett (Oxford University), Mr. Hugh Mortimer (Oxford University)


Voice of the Future also featured a special science "Question Time", chaired by Phil Willis MP, in which STSC members fielded questions from the audience as in the popular BBC TV show of the same name. RSC chief executive Dr Richard Pike was on the panel, as were Des Turner and Brian Iddon MPs.  The panel were asked about creationism being taught in schools, clean coal technology and making the school science curriculum more exciting.  Voice of the Future is one of a number of events taking place in Parliament during National Science week - but the only one in which both Mr Wicks and the Select Committee have both taken part.  Members of the UK Youth Parliament and some A-level students were among the young scientists in attendance.

RSC chief executive Dr Richard Pike said: "This was a unique opportunity for young scientists from all over the country to find out first hand how science is dealt with by government and parliament.  The Select Committee spends its whole year asking questions - on this occasion they were answering them!"  The young scientists and engineers also had the opportunity to meet their local constituency MPs.