Kinetic Inductance Detector Arrays at 25 Microns

Dr. Peter Day (JPL)

We have been developing techniques for implementing Kinetic Inductance Detector (KID) arrays for a FIR space mission covering a wavelength range of approximately 200 to 25 microns. There has been little work so far on KIDs at the short wavelength end of that range. We will present a possible design and a couple of technical advances enabling closely packed detectors covering a band from about 25 to 40 microns. One advance is an absorber design that allows for efficient absorption in a small metal volume consistent with the demanding sensitivity requirement. The other involves the fabrication of small area capacitors with suitably low dielectric noise.

The Didymos Binary Asteroid System in the Infrared - Observations with JWST and the NASA IRTF

Dr. Cristina Thomas (Northern Arizona University)

NASA’s DART (Double Asteroid Redirection Test) impacted Dimorphos, the secondary of the near-Earth binary asteroid (65803) Didymos, on September 26, 2022, in the first test of kinetic impact for asteroid deflection. Telescopes around the world and in space monitored the Didymos-Dimorphos system before, during, and after the impact. I will discuss the physical properties of the targets as observed by JWST and the NASA IRTF in the time near the impact when the target was close to Earth.

JWST observed the Didymos system with NIRCam over a period of approximately 5 hours before and after impact. These observations show the evolution of the ejecta near the asteroids in the hours after impact. We also obtained NIRSpec fixed slit spectroscopy (0.6 – 5.3 microns) and MIRI medium resolution spectroscopy (4.9 – 27.9 microns) in two months after impact. The NIRSpec data show significant thermal excess and we performed an independent assessment of Didymos’ thermal properties. The MIRI spectra have spectral features consistent with S-type, ordinary chondrite-like objects.

Our NASA IRTF observations were taken in a nightly sequence around the time of impact. Our first observations after the impact contained a large fraction of dust from Dimorphos which enabled us to study the secondary and investigate space weathering.