"Thanks EP.

Thanks, Nick - your reply demonstrates the claim I made in Part 2: Manned Mars supporters will advocate the expenditure of several billion to deal with the NEO hazard rather than see manned Mars flight delayed

" Why don't you return to your statistics where you claim that events with a repeat interval of 100,000 years are occurring every 200 years.

There is a difference between data and statistics. The historical data (and geological data in some cases) is as I stated. In addition to confirming geological work, there is also a large amount of historical data currently being retrieved indicating even more strikes than those listed in the short list given in the post "< 1 kilometer".

Perhaps a disintegrating comet has led to a recent peak in impacts, but this has not been confirmed. In any case, there is no evidence that if a recent peak did occur, it has finished, and we are safely through it. If anything, the historical data seems to indicate that if it exists, it is on-going.

"It follows logically that many in LEO are better than many on the Moon, and they are also cheaper, btw)

While either system provides better resolution than ground based assets, the better field is only provided by
telescopes not in LEO, but rather elsewhere in free space. This being the case, the Moon is cheaper when you throw in servicing costs - and how many servicing flights has the Hubble had?

"Radar is as good from Earth as from the Moon (Trade-off noise levels vs size..."

But you can't trade off the noise levels when trying to locate Tunguska class and Meteor Crater class small impactors around 75 meters in diameter.

"My desktop PC is powerful enough to process and blink-compare every single overlapping image pair from a Hubble-class LEO observatory in real
time.

The data rates from NEO detection systems are higher than from Hubble. A small ground based NEO system currently is using 24 state of the art desktops to analyze data, and is still hitting bottle necks, and does not perform in real time. The data rates from space based sensors will be far higher -

EP