First, what science are we trying to do? This tutorial page goes into a fair bit of detail, but briefly, we’re using small craters on the Moon (around 10 meters to 1 km across — that’s about 13 ft to 0.6 miles) to better understand the chronology (what happened when?) and the details about how we actually identify craters in the first place.
To do this, we ask you to identify craters. Simple as that, right?
Not quite — we don’t just have you look at an image and then that’s it. We aim to have 15 different people look at every small, 450 by 450 pixel sub-image, each sub-image being part of a larger image taken by the Lunar Reconnaissance Orbiter Camera (“LROC”). All that you see is the individual images, and the number of craters that everyone has marked.
At the moment, we have 15 different “master images” that cover the Apollo 15 landing site that we’ve divided into the sub-imagees that we’re trying to have fully marked up. Of those 15 images, I’ve already identified the craters in one, and we’re using that as calibration to see how my craters compare with all of yours’.
Of those 15 images, all but 1 have at least been looked at a little bit by some people. 6 of those 15 have been completely finished: An average of 15 to 18.4 people have looked at each sub-image that makes them up. One of the remaining is half-way done with just over 8 people having looked at each sub-image. Another has 4 people per sub-image, while the remaining are under 3. So in the end, we’re around half-way through this initial science question at the Apollo 15 landing site.
We’re also nearly ready to submit our first paper — how we actually go from each of your individual markings to a “consensus crater.” But that’s a different blog post.
Greetings AstroStu, do you know if there exists a database on Mars craters larger than 1 km that can be downloaded or consulted online? Thanks !
Yes, for this was my dissertation work. USGS hosts it, and I have a searchable site for it.
although in the ASCII database I did not find, for example, Hellas, Argyre, Isidis…
I did not include those largest basins (Cryse, Acidallia are also missing) because there is SO much uncertainty with their rims. Other people have studied them much more extensively, so I left them out.
The USGS Gazetteer of Planetary Nomenclature has the generally agreed upon sizes and center locations for those kinds of features. Most of them are in the planitia area.
is there any publication where all these large basins are shown once with their ages?
thanks
r u sjrobbins?
Indeed, he is me. Well, I’m not the first Stuart J Robbins that shows up on Google, that’s just some actor guy. Oh wait, I take that back, apparently that IMDB link is me for photos I provided the BBC. Anyway …
The most complete paper that is currently published is by Stephanie Werner (Werner, S.C. (2008) “The Early Martian Evolution – Constraints from Basin Formation Ages”). Caleb Fassett also has a paper where he dated three of the basins (Fassett, C.I., and J.W. Head (2011) “Sequence and Timing of Conditions on Early Mars”). And then there’s Herb Frey’s work dating possible basins (Frey, H.V. (2008) “Ages of Very Large Impact Basins on Mars – Implications for the Late Heavy Bombardment in the Inner Solar System”).
I have a paper currently in review that’s age-dating 78 of the ≥150 km diameter craters on Mars. But other than that Stephanie’s paper is probably what you would want.
That was excellent ! thanks a lot ! cheers !