# What would a lunar meteorite impact look like from the Earth? **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [July 12, 2013, 5:29pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336 "2013-07-12T17:29:08Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![tfabris](https://avatars.discourse-cdn.com/v4/letter/t/3be4f8/32.png) [@tfabris](https://boards.straightdope.com/u/tfabris)\ **Post date:** [July 12, 2013, 5:29pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336/1 "2013-07-12T17:29:08Z")
I’m surprised that today’s column didn’t mention the Canterbury Monks and the Giordano Bruno crater. Supposedly these monks watched a lunar impact in the 12th century, and wrote a recorded description of it, in a time before anyone could have understood what it was they were watching. I remember this passage being quoted in Carl Sagan’s book “Cosmos”, which I read in my childhood. Here’s the Wikipedia article on it: > **[Giordano Bruno (crater)](https://en.wikipedia.org/wiki/Giordano_Bruno_(crater))** > > Giordano Bruno is a 22-kilometre (14 mi) lunar impact crater on the far side of the Moon, just beyond the northeastern limb. It lies in an area that can be viewed during a favorable libration, although the area is viewed from the side and not much detail can be seen. It lies between the craters Harkhebi to the northwest and Szilard to the southeast. > When viewed from orbit, Giordano Bruno is at the center of a symmetrical ray system of ejecta that has a higher albedo than the surrounding surfac... What did it look like? The moon was a crescent at the time, and the monks say that the “upper horn split in two”, I assume a description of the shockwave and debris cone moving away from the lit limb of the moon’s surface. Here is rest of their account of what it looked like: “From the midpoint of the division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals and sparks. Meanwhile the body of the Moon which was below writhed, as it were in anxiety, and to put it in the words of those who reported it to me and saw it with their own eyes, the Moon throbbed like a wounded snake. Afterwards it resumed its proper state. This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal. Then, after these transformations, the Moon from horn to horn, that is along its whole length, took on a blackish appearance.” The Wikipedia article is careful to point out that the connection between the monks’ observation and the Giordano Bruno crater is merely a theory, and that there are some problems with the theory. We may never know what the monks really saw, if indeed their account is even factual. But I love the idea that humans could have witnessed such an amazing and catyclysmic planetary event with the naked eye. It’s like a Doctor Who episode in real life. ---
**Author:** ![DirkGntly](https://avatars.discourse-cdn.com/v4/letter/d/d9b06d/32.png) [@DirkGntly](https://boards.straightdope.com/u/DirkGntly)\ **Post date:** [July 12, 2013, 6:42pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336/2 "2013-07-12T18:42:53Z")
Okay, I did the math. Observable lunar days per the article (rounding to full years since 2005): 960 Observable impacts during that time: 300-ish That sounds to me like there were OBSERVABLE impacts on average, of nearly 1 every 3 days! Sounds like Luna isn’t exactly the safest place to set up a permanent colony (depending, of course, on location - maybe the poles would be best?) ---
**Author:** ![tfabris](https://avatars.discourse-cdn.com/v4/letter/t/3be4f8/32.png) [@tfabris](https://boards.straightdope.com/u/tfabris)\ **Post date:** [July 12, 2013, 6:48pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336/3 "2013-07-12T18:48:56Z")
True, the moon is quite frequently pelted. And if you lived there, you wouldn’t just be worrying about the big ones. Even a tiny invisible micrometeorite could ruin your day real quick, if it caused your magic smoke to leak out. Of course, we see observable impacts on the Earth all the time too. They’re constant! They’re just impacting that nice convenient shield we’ve got enveloping our planet. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [July 12, 2013, 6:51pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336/4 "2013-07-12T18:51:26Z")
> [@tfabris](#): > > I’m surprised that today’s column didn’t mention the Canterbury Monks and the Giordano Bruno crater. Supposedly these monks watched a lunar impact in the 12th century, and wrote a recorded description of it, in a time before anyone could have understood what it was they were watching. I remember this passage being quoted in Carl Sagan’s book “Cosmos”, which I read in my childhood. Here’s the Wikipedia article on it: > > [Giordano Bruno (crater) - Wikipedia](http://en.wikipedia.org/wiki/Giordano_Bruno_(crater)) Trivial editorial heads-up: your URL is missing its trailing parenthesis. It’s there in the text, but it’s not part of the URL tag you’re using. However, it appears it’s not your fault. I tried “correcting” the URL tag and the stupid vBulletin editor did it to me, too – moved the closing parenthesis outside the URL close tag. Better bet might be to use a [different type of tag](http://en.wikipedia.org/wiki/Giordano_Bruno_(crater)) ETA: This [isn’t the first time](http://boards.straightdope.com/sdmb/archive/index.php/t-672388.html) this bug has been noted. ---
**Author:** ![tfabris](https://avatars.discourse-cdn.com/v4/letter/t/3be4f8/32.png) [@tfabris](https://boards.straightdope.com/u/tfabris)\ **Post date:** [July 12, 2013, 7:03pm UTC](https://boards.straightdope.com/t/what-would-a-lunar-meteorite-impact-look-like-from-the-earth/663336/5 "2013-07-12T19:03:42Z")
Thanks, I noticed that happened as well. It’s a common problem with any software that tries to parse URLs and turn them into links (BBS’s, email readers, usenet readers, twitter clients, etc). Hey, I pasted in a correct URL, it was the BBS software that mangled it. In my line of work, we call that NOB (“Not Our Bug”). 🙂