Rob Barrie, Science and Technology Editor, talks to Dr Wilkins about his upcoming research using the James Webb telescope.
Dr Stephen Wilkins and his team at the University of Sussex will be amongst the first scientists in the world to use the recently launched James Webb Telescope to help unravel the mysteries of the early universe. In late January, Webb – dubbed the successor to Hubble – reached its final position 1.5 million kilometres from Earth, meaning work can soon start on the most advanced telescope scientists have built. Dr Wilkins, who has been running simulation models of the universe at Sussex since Hubble’s efficacy has plateaued, is looking forward to switching focus back to the observational side of astronomy. He and his team will be looking for the very first galaxies born in our universe, as he explains:
“We know as we look out into the universe, we’re effectively looking back in time, because light takes a certain amount of time to reach us, and so if we can look far enough away, we can see the very first stars and galaxies to form in our universe. Our focus here in Sussex is exploiting the imaging [from Webb], to actually find these galaxies. We’re a part of 7 different teams that have got time on the telescope, and so our job within several of those teams is to develop the software to find the very faintest galaxies, because we know that the galaxies that we’re interested in [are] going to be the ones that are very faint, they’re not nearby, they’re very far away, so we’re looking for the really tiny blurry dots. What we’re really caring about is developing software to find those galaxies and then once we’ve found [them], trying to figure out what we can learn from them. We’re very much on the discovery side here at Sussex, that’s what we care about, leaving other bits of the follow up to other members of the teams.”
Webb is the result of an international collaboration between NASA, the European Space Agency and the Canadian Space Agency, and is the latest in a long line of orbiting telescopes. Dr Wilkins explains how technologically advanced Webb is compared to its predecessors:
“Webb will be ten to hundred times better than its predecessors. It’s very modern so it’s got very sensitive instrumentation and it’s deep in space. All of these things are particularly important when you’re looking at very faint objects. Obviously, you want to avoid any sources of extra light like the sun and the Earth [and] you obviously want as big a telescope as possible to collect as much light. Probably the main thing that makes it different from other telescopes including Hubble, is the fact that it doesn’t look at the light that we can see with our own eyes […], it sees infrared light, and there’s lots of good scientific reasons why we want to do that. Although, one of the consequences of looking in the infrared light is – this is one of the reasons why we want to move the telescope [to its final position] to keep it very cool – because any object will produce infrared light, so the cooler you are, the less infrared light you’re going to produce. This also motivates the fact why the telescope looks gold, and that’s because the mirror actually is coated in a fine layer of gold because that reflects infrared light better than say aluminium or silver or steel. Webb also goes a little bit further beyond that and allows us to do spectroscopy. So instead of just picking an image of the universe, we can break up the light from distant objects into their constituent wavelengths which allows us to do a whole load more science and that’s something that I think is really exciting and is probably the biggest difference between Webb and Hubble.”
As he discusses further, Dr Wilkins is hopeful that findings from Webb may change our current view of the early universe:
“I’m not saying Webb will discover something as important [as dark matter and dark energy] because Webb is designed more to look at smaller things than the universe as a whole. [Webb will] look through dust, which is really important to understand how stars form and evolve, because when stars are first born, they’re formed in these very dusty clouds, and so we’ll be able to understand that for the first time. In my area obviously we’re hoping to find lots of galaxies close to the early universe. I have no idea whether they’re going to agree with our models or not. If they’re very different then that means we’ve learnt something new about the universe and we’ve got to go change the models. But if they agree with the models then that’s also a success – it’s a win-win situation.”
Dr Wilkins adds that Webb will also carry out imaging within our own solar system, and though tentative about the time-frame, he explains that the potential findings could be immense:
“I think possibly one of the things that will ultimately capture the public’s attention, though, is very ‘nearby’ science that Webb will do. In particular, Webb will look at the atmospheres of planets around other stars, and via spectroscopy it will tell us whether those atmospheres contain water, oxygen, methane, carbon dioxide – all of those crucial molecules. It will do this for planets like the Earth around other stars, […] so there is potential that Webb will discover a planet like the Earth, potentially even start telling us that that planet might be habitable, or might be inhabited – at least by some type of plant-analogous life on those planets. So that’s incredibly exciting, and that’s potentially civilisation-changing discoveries. My strong suspicion is that Webb won’t quite make that discovery, but it’ll start allowing us to actually do that experiment and maybe we’ll have to wait a little longer until we do that. But if we [do] see life somewhere else in the universe, certainly somewhere relatively nearby, then that tells us a lot about our universe and a lot about our place in the universe. Which, like I said, is potentially civilisation-changing.”
Astronomy has always attracted public interest, but in times where misinformation around science is widespread, Dr Wilkins affirms the necessity for public accessibility to findings from Webb, so this can enable scientific learning:
“I think it’s important that scientists, certainly publicly-funded scientists like most astronomers, I think it’s our responsibility to make our findings as publicly accessible as possible. I think we know that there is a strong appetite for anything to do with space – that hasn’t really changed in the last fifty or sixty years! I think there’s perhaps a bit more of an urgency over the last few years for that type of [scientific] literacy to improve, as we’re seeing so much misinformation around the pandemic. I’m not saying that astronomers can really solve that issue, but if we’re able to communicate what we found clearly and people believe us, and feel trust in us, hopefully that builds trust in science overall. I don’t think it’s crucial for people’s lives to learn more about the universe, but I think we should enable them to learn more about the universe because certainly one of my favourite things is just learning stuff, and I think a lot of other people feel the same, even if they wouldn’t say they like science. I think everybody actually enjoys learning new things, be it how to dance or the fundamental origins of the universe. It’s something that should be as accessible as possible because it does bring people happiness.”
Finally, for those in Sussex wanting to reach closer to the night sky, Dr Wilkins gives his top recommendations of where to go stargazing:
“I’m lucky enough that I live in a village in the national park which doesn’t have any streetlights despite being a relatively large village, so I’ve always been quite privileged when I jump off the bus its often pitch black when I get home, and I can look up and I can see the milky way. So this contrasts quite sharply with my upbringing. I grew up in the middle of a big city up north, and I certainly didn’t see the milky way until I was much older so probably in my late teens I think it was before I really saw the milky way, before I really had that opportunity and really noticed it. If I could go stargazing anywhere, I think sitting near Beachy Head and looking out to the sea there, obviously it’s still quite dark outside but it’s surrounded by the beautiful scenery and, I’ve never managed to do it myself, but you see people who capture astrophotography from there and the contrast of the milky way and the cliffs as well, it’s pretty impressive. So Beachy Head, Seven Sisters, Cuckmere Haven, [they are] the jewels in the landscape of Sussex’s crown.”
