This month’s issue (Oct) of PSJ (Planetary Science Journal) has planetary defense coverage. In vol 5, #10:
Masiero, J. R. Linder, T. Mainzer, A. et al. Visual-band Brightnesses of Near-Earth Objects that will be Discovered … p. 222 ad7859
leva, S. Mazotta Epifani, E. Dotto E. et al. Near-infrared Spectral Homogeneity of the Didymos System Before and After the DART… p. 225 ad793e
The NEO Surveyor Mission is being built as I type. The observatory will view in infrared, from space (the Sun-Earth L1 point), to spot asteroid threats. As a search telescope, it should get follow-up observations from other telescopes. As an infrared telescope at L1, the correspondence between NEOSM and some hypothetical follow-up is not obvious. Are there objects which will show up in infrared, but not in optical bands (or “visual-band,” which is where most telescopes work)? Are there objects which will be in the Sun’s glare from the ground, and how would we follow that up? NEOSM has some ability to revisit a sky field, which means we’ll have more than just that initial detection, but the questions still stand. The mission will launch in a few more years now (“few” by OldSpace norms, not NewSpace); the astronomy community should be making preparations.
Preparations… a bit like we did for the DART program. Knowing that a spacecraft would be sent to its ‘death’ as a divert experiment, telescopes around the world (and Hubble, and Webb) were poised to study the impact event. Here, a team using the TNG (Italy’s Galileo telescope, or Telescopio Nazionale Galileo) took “before” observations of the Didymos-Dimorphos binary system. They then got additional data as the “after.” From a ground telescope, the amount seen is nothing dramatic (that’s what the Hera mission is for) but it doesn’t hurt to have the data. In particular, lots of telescopes can do visual-band studies, but TNG made it a point to view in the near-infrared. This is important because some qualities of asteroids are seen just beyond the red limit of our visual band; the olivine absorption feature at ~0.9 micrometers, and in general a spectral slope, running from visual into the infrared. Ieva et al.’s paper checks Didymos for this.