CNN's October 31, 2022 ‘Planet killer’ asteroid spotted hiding in the sun’s glare links to Sheppard et al. (2022) A Deep and Wide Twilight Survey for Asteroids Interior to Earth and Venus. The abstract is long, and includes sentences like
We are conducting a survey using twilight time on the Dark Energy Camera with the Blanco 4 m telescope in Chile to look for objects interior to Earth’s and Venus’ orbits.
Our new discovery 2021 PH27 has the smallest semimajor axis known for an asteroid, 0.4617 au, and the largest general relativistic effects (53 arcsec/century) known for any body in the solar system. The survey has detected ∼15% of all known Atira NEOs. We put strong constraints on any stable population of Venus co-orbital resonance objects existing, as well as the Atira and Vatira asteroid classes.
Atria asteroids never go out as far as Earth's orbit; Vatria and Vulcanoids never as far as Venus' and Mercury's, respectively.
However, it's hard for me to understand how much we can get from the following sentence in the abstract.
To date we have covered 624 square degrees of sky near to and interior to the orbit of Venus.
Since both the Earth and the asteroids are rotating around the Sun and at substantially different rates, somehow citing the amount of sky covered seems a bit misleading. Couldn't all those square degrees that have been covered be full of undiscovered objects a year or two later? They're not marked "finished, done, no need to revisit later" are they?
Question: What exactly is the meaning of "To date we have covered 624 square degrees of sky near to and interior to the orbit of Venus"?
Isn't there a higher dimensional space that takes into account period vs radius (as well as the problem with the Sun's glare" that is a more honest metric of how far along they've progressed?