The 2024 SPIE (Society of Photo-optical Instrumentation Engineers) Astronomical Telescopes and Instrumentation conference is big, really big. For lack of days and days of time and effort, my observations:
– The era of submillimeter/Terahertz astronomy is coming, or arguably here now. (There’s not that much separating the 0.99mm wavelength definition from the 1000 GHz frequency definition.) Herschel is long gone, long enough for the field to have advanced to the point of a next-generation project. ALMA was always designed to reach through and past 1000 GHz, and the upgrades to do so are continuing. SPICA was a JAXA mission concept, that fell back to a JAXA/ESA concept… that fell out completely. The cancellation of SPICA did not quash the issue, it opened a gap, and plenty would like to fill that gap (which includes SOFIA getting slashed- truly pound-foolish). Besides the PRIMA concept by NASA to reconstitute a ‘SPICA-like’ mission, numerous balloon missions will observe in this range. And, in a partial sense, the Event Horizon Telescope will be upgraded to, well, approach this range. The pull of the EHT- drawing front-page headlines around the world- cannot be denied. Therefore, labs and research groups and suppliers around the world are looking to do these 0.9x mm/1xxx GHz upgrades.
– The era of infrared astronomy- Spitzer, Akari, the supplementary WISE, arguably Herschel- never ended. James Webb is certainly up and running (…finally), but the wider world of non-silicon detection isn’t waiting on, much less tied to, any one telescope/mission. There are enough industrial, medical, military, and now consumer applications of infrared (however you define that, wavelength-wise) that loss of Spitzer, Herschel, Akari, etc. meant little.
– In particular, the ELT era (commissioning of the TMT, GMT, and E-ELT telescopes) is largely going to be an infrared era. ELT, for one, is no paper project; the instruments are well advanced and intending for the telescope to have a productive first-light and beyond.
– Speaking of ELTs, the three(?) telescopes will be largely infrared, and essentially adaptive optics showcases. Without AO, the telescopes would be light buckets. Blur vacuums. The field of adaptive optics is continuing, and continuing at speed. The previous generation of telescopes, about to be relegated to ‘second-tier,’ will still be upgraded to next-generation AO systems and components. As with infrared, there are also military, telecom, and medical people to fund the research and buy the resulting systems.
– Those advanced AO systems will be driven by new detectors. The prospects of single-photon instruments are here and real, and not just microchannel/avalanche technology with noise and nonlinearities. In particular, “quantum telescopes” will not be just another buzzwordy use of “quantum.” The ability to pick out one lone photon- and time-tag its arrival- will, if the claims hold up, nearly solve the issue of ground observations through Earth’s atmosphere. The driving use case (at least, for astronomy, not lasercom or early warning) of exoplanets is leading the field towards these ultra-sensitive, ultra-precise instruments.
– and we can’t forget the ‘normal’ stuff. Optical polishing and figuring and substrates and so on. The terahertz range requires new concepts and examples in ‘optics’ that aren’t optical. The emergence of metamaterials is acceptable and tolerable at submillimeter/infrared wavelengths, so those applications are coming sooner. Only after that will visible applications unleash a tidal wave, along with diffractive and freeform optics.
– …I would be negligent if I failed to report all the AI/ML/etc. exhibitors. Even though this subfield is full of buzzwords, pretenders, speculators/bandwagon jumpers, and assorted hype-slingers, I have to admit: someone, somewhere, will find the killer app. The astronomy problem that gets solved by artificial intelligence, and solved by no one else. It’s just a bit soon to say what the someone, somewhere will be. Or maybe I’m just too tired of the pretenders and hype to make such distinctions.
– I keep coming back to infrared, but the ultraviolet people aren’t exactly giving up. The lack of a recent ultraviolet space mission just makes the questions back up like a highway accident. Exoplanets are currently drawing the headlines, attention, and funding, but stellar physics did not stop and largely takes place in ultraviolet. And galaxies are, at first glance, lots of stars. Can’t do galactic studies without stellar emissions.
I’ll have more to say- have to keep track of all this.