Markus Hammonds is a final year PhD student in Molecular Astrophysics who’s normally found blogging at Supernova Condensate. He spends his life looking at very small things on very large scales, and trying to better understand the chemistry of interstellar space.
Isaac Newton taught us that every action has an equal and opposite reaction. What he didn’t mention, however, was the fact that this is true for more than just physics. It’s an unfortunate fact in the academic world, that science costs money. Typically, the better or more exciting the feat being attempted, the more expensive it is. While as scientists we all have to learn to accept this, it still comes as little consolation to those who get caught in the aftermath of cancelled projects.
Sadly, I’m no stranger to this. I was welcomed into the world of astronomy research in 2007 by the Science and Technology Facilities Council (STFC) slashing £80 million from the UK physics and astronomy budget and in all honesty, the less said about that debacle, the better. However, despite the loss of considerable amounts of hands-on training I might otherwise have had, things could have been a lot worse. Unfortunately, for some of us, things just did get a lot worse. The European Space Agency’s (ESA’s) recent decision to discontinue work on the Advanced Telescope for High Energy Astrophysics (ATHENA) X-ray observatory has provoked quite a reaction from the worldwide community of high energy astronomers. A letter of support urging ESA to, “take all necessary steps to adopt the X-ray observatory Athena as soon as possible for operation in the 2020s”, received over a thousand signatures within the first 24 hours.
PhD students and early career researchers are among the hardest hit by setbacks such as these. We grudgingly have to acknowledge that we depend upon whoever controls the purse strings. After all, we’re all at the mercy of limited budgets. There’s only so much money available to fund the science we all so eagerly want to be getting on with. Unfortunately, difficult decisions have to be made and often as one group of scientists rejoices, another has to deal with the gloomy consequences. Unfortunately in this case, the fallout from delays to ATHENA are potentially a bit worse than simply having to wait until 2028 for the next ESA funding opportunity.
You see, X-ray astronomy is something of a specialist art. The realm of high energy astrophysical phenomena, concerns curious and poorly understood objects, such as black hole event horizons, supernova remnants and active galactic nuclei. Speaking as someone who works mostly with optical telescopes, without sufficient help and guidance I’d be quite lost in the world of X-rays. But therein lies the problem. With a huge setback like this, many specialists will be forced to disperse to other fields, or even (the thing we all fear the most) leave astronomy altogether. There won’t be the same amount of experts to guide the field anymore and certainly not with the same skill level. The fear is that all of X-ray astronomy will lose momentum and the skill levels of those involved will be set back by years. Simultaneously, while research into high energy astrophysics stagnates, all other fields will be progressing at an even faster rate. Over the next few decades, as some areas of astronomy move forward in leaps and bounds, life is going to get difficult for the X-ray community. With mostly ageing instruments available, there’s likely to be a shortage of both data and funding to go around. X-rays may well be left out in the cold.
ATHENA has not been without her setbacks already. The original plan was for an X-ray observatory called XEUS (X-ray Evolving Universe Spectroscopy), as a successor to the current X-ray Multi-Mirror Newton (XMM-Newton). XEUS was being planned in cooperation with the Japan Aerospace Exploration Agency (JAXA). Then around 2008, when NASA joined the team, XEUS was renamed to the International X-ray Observatory (IXO). Unfortunately, the plans for IXO fell apart last year when NASA abruptly withdrew their support for the project. Just like the axe to Zeus’ skull in Greek mythology, this spawned ATHENA as ESA’s attempt to save all of the work they’d put into the project.
A space observatory is the only really viable option for such observations, as Earth’s atmosphere blocks X-rays from reaching the surface (while this may be good news for sunbathers, it’s less helpful for astronomers). And ATHENA was set to be a truly grand space telescope; the largest of its kind ever constructed, with the only size constraint being the ability to actually get it into orbit. Richard Willingale from Leicester University is quoted as saying;
“It is as big as we can get inside an Ariane 5 rocket.”
A dramatic improvement over XMM Newton’s 4300 square centimetre collecting area, ATHENA would have 3 square metres of X-ray mirror, giving an angular resolution of 5 arcseconds (1/3600 of a degree). Other huge projects are underway to improve all other areas of astronomy, such as the Square Kilometre Array (SKA) at radio frequencies, and the 40 metre European Extremely Large Telescope (E-ELT) for visible light. All the pieces fit perfectly. A missing X-ray observatory of the same calibre doesn’t just affect X-ray astronomy, but astronomy in general. In a world where more and more astronomers are coming to realise that seeing the big picture requires looking across a wide range of wavelengths, without ATHENA we’ll be missing a large piece of the picture. In many cases, perhaps a vital one.
The project which beat ATHENA to funding is, of course, not an uninteresting one. The JUpiter ICy moon Explorer (making the rather forced acronym of JUICE) is currently proceeding as ESA’s number one. Perhaps at the end of the day, visiting other planets and venturing back to the outer solar system is simply more captivating to most people than looking at X-ray emissions from black holes (and don’t get me wrong, I’m a firm advocate of solar system exploration). I guess it’s understandable that JUICE was chosen. With the exception of New Horizons’ trip to Pluto, it’s been quite a long time since anything from Earth has travelled to the outer reaches of the solar system. Sadly, this comes at the cost of potentially bleak futures in other areas of science. For some people, this particular JUICE tastes decidedly bitter.