What kind of early detection of long period comets do we have in place?

Question

What kind of early detection of long period comets do we have in place?

Answer 1

A couple of arrays that are not looking for them. It's likely that an amateur astronomer would detect it before a larger more powerful telescope even know of it.

Answer 2

Not much.  We have sky surveys for looking for asteroids, usually concentrating on the ecliptic - where the planets and most other things orbit.  These surveys do find comets, but not all of them.  Amateur astronomers still find comets, looking by eye, and using CCD cameras on their scopes.  It seems to still take 1200 hours to find a comet, despite the surveys.

Early detection of long period comets is difficult for two reasons.  One is that to be detected early, you have to find them when they are far from the Sun.  They'd be dim if they were just far from the Sun, but they also don't develop tails way out there, so they're tiny too.  That makes them really dim.  Now, the VLT has been used to image Hale Bopp and Comet Halley when they are at the distance of Neptune.  But they knew where to look.  You don't use a billion dollar telescope to do sky surveys for comets.  And you don't know where they're going to come from (that's why you're looking), but for long period comets you are sure that they can come from anywhere.

But the Large Synoptic Survey Telescope is being built.  In March, they started working on the primary mirror.  The design is complicated, but it will have the collecting area of a 6.7 meter mirror.  It will cover the entire sky that is visible from it's location every three days.  30 terabytes of data per night.  And the survey will be able to detect objects as dim as 25th magnitude.  This is awesome for 15 second exposures.

Answer 3

i once read about a massive comet that was recorded in china, south asia ( india (pakistan), in 1100 b.c.

i read that somewhere at the library

Answer 4

The Near Earth Object (NEO) program has been running for a few years now. It's NASA led and I don't know if ESA or Russia are running similar programs.

Some people would argue that we're long overdue for a significant impact. They base this hypothesis on good mathematical probabilities. I'm more inclined to go with the lottery/chaos alternative. It's a random event that isn't based on a bus timetable. Intervals aren't regular and therefore unpredictable.