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We have used Minor Planet Center data and tools to explore the discovery circumstances and properties of the currently known population of over 10,000 NEAs, and to quantify the challenges for follow-up from ground-based telescopes. The increasing rate of discovery has grown to ~1,000/year as surveys have become more sensitive, by 1mag every ~7.5 years. However, discoveries of large (H =< 22) NEAs have remained stable at ~365/year over the past decade, at which rate the 2005 Congressional mandate to find 90% of 140m NEAs will not be met before 2030. Meanwhile, characterization is falling farther behind: Fewer than 10% of NEAs are well characterized in terms of size, rotation periods, and spectra, and at current rates of follow-up it will take about a century to determine them even for the known population. Over 60% of NEAs have an orbital uncertainty parameter, U >= 4, making reacquisition more than a year following discovery difficult; for H > 22 this fraction is over 90%. We argue that rapid follow-up will be essential to characterize newly-discovered NEAs. Most new NEAs are found within 0.5mag of peak brightness and fade quickly, typically by 0.5/3.5/5mag after 1/4/6 weeks. About 80% have synodic periods of <3 years that bring them close to Earth several times a decade. However, follow-up observations on subsequent apparitions will be near impossible for the bulk of new discoveries, as these will be H > 22 NEAs that tend to return 100 times fainter. We show that for characterization to keep pace with discovery would require: Visible spectroscopy within days with a dedicated >2m telescope; long-arc astrometry, used also for phase curves, with a >4m telescope; and fast-cadence (<min) lightcurves obtained within days with a >= 4m telescope. For the already-known large (H =< 22) NEAs, subsequent-apparition spectroscopy, astrometry, and photometry could be done with 1-2m telescopes.
In August 2002, the near-Earth asteroid 2002 NY40, made its closest approach to the Earth. This provided an opportunity to study a near-Earth asteroid with a variety of instruments. Several of the telescopes at the Maui Space Surveillance System were
The Apollo-type near-Earth asteroid (155140) 2005 UD is thought to be a member of the Phaethon-Geminid meteor stream Complex (PGC). Its basic physical parameters are important for unveiling its origin and its relationship to the other PGC members as
The near-Earth asteroid (3200) Phaethon is an intriguing object: its perihelion is at only 0.14 au and is associated with the Geminid meteor stream. We aim to use all available disk-integrated optical data to derive a reliable convex shape model of P
A small number of anomalously bright boulders on the near-Earth, rubble-pile asteroid (101955) Bennu were recently identified as eucritic material originating from asteroid (4) Vesta. Building on this discovery, we explored the global presence of exo
Small near-Earth asteroids (>20 meters) are interesting because they are progenitors for meteorites in our terrestrial collection. Crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors is the physical