Archive | October 2011

Halloween Moon

Humans are good at recognising patterns and picking out shapes from background noise. Sometimes we see what isn’t really there. To celebrate Halloween here are a few ghoulish “items” from our forum Pareidolia thread. You can see more here.

Ghoulish face

Thanks to forum members placidstorm and ElisabethB.

Happy Halloween!


Flaming Heart Moon fish

Forum regular Tom128 originally found this feature back in February and called it a Valentine flaming heart. It was recently rediscovered by kodemunkey, champion of the ACT-REACT Quick Map search tool and became the Moon fish. It is situated at the end of a long landslide on the walls of Chladni crater located at 4.01N, 1.04 E. Moon Zoo team member IreneAnt thought is was likely caused by a low velocity impact (either primary or secondary) which disturbed material on the crater wall enough to trigger a separate mini landslide.

NAC ref: M109229693RE

We are collecting landslides such as this on the forum. They can form quite intricate patterns and because they have not been eroded by further impacts they are thought to be relatively young features (which in lunar terms means less than 1 billion years old).

There are more unusual features to be found in the forum’s Pareidolia collection.

And the answer is…


How the voting went:

Picture 1 is Mercury      15.6%
Picture 2 is the Moon    15.6%

Picture 1 is the Moon      34.4%
Picture 2 is Mercury         34.4%

So how did you do? As you can see most people got this wrong! I managed to find a region of the Moon that didn’t look too obviously Moon-like so don’t feel too bad if you got them the wrong way round. The coordinates are the same for both Mercury and the Moon at lat –45 : long 125. This takes us to the lunar region around Planck and Van der Waals craters on the far side which looks very much like Mercury. At first glance the two bodies do look very similar but there are some differences – though not all obvious from the two pictures.

  • Mercury has more intercrater plains (its oldest surface) than the Moon.
  • Ejecta deposits and secondary craters are less extensive on Mercury due to its higher gravity field. The region of Mercury chosen is atypical in this respect though there are some clues.
  • There are more tectonic features on Mercury than on the Moon (rupes, ridges, troughs etc). The lunar region I chose highlights some lesser-known tectonic features.
  • The Moon (particularly the nearside has expanses of bright highland terrain and dark basaltic maria.  Mercury does not, though it does have splashes of bright relatively fresh craters against the darker terrain and in this respect has more in common with the lunar far side.
  • Mercury has a magnetic field indicating it still has a molten core whereas the Moon has pockets of magnetism but no global magnetic field.

Well done to those who got it right. It wasn’t easy!

The Geological History of Mercury Spudis 2001
The tectonics of Mercury Watters and Nimmo, 2009
The tectonics of Mercury Melosh and McKinnon, 1988

So you think you know the Moon

So after all the clicking on Moon Zoo you should know what the lunar surface looks like! But do you? Are you a true lunarphile? Like the Moon, Mercury is also rocky and heavily cratered. Can you spot the difference?
Study the two pictures below and decide which shows lunar craters and which shows craters on Mercury. You can vote on the Moon Zoo forum.
Voting ends Sunday 16 October. Answer next week!

Picture 1 

Picture 2


The Moonometer (TM) Challenge!

Join in the Moonometer (TM) challenge! We need you to classify 25,000 images between now and Monday to celebrate International Observe the Moon Night. Just go to Moon Zoo and start clicking!

International Observe the Moon Night – 8 October 2011

This year’s IOTMN is just one day away. This is the one day of the year when all lunarphiles hope for clear skies and if we get them there will be a lovely waxing gibbous 11 day old Moon to observe.

11 day old Moon – J Wilkinson

This will be ideal for observing the spectacular Kepler and Copernicus craters and the dramatic Apennine Mountains and Mare Imbrium. Check the IOTMN website to see if there is an observing event near you. But the great thing about the Moon is that you don’t need a telescope or binoculars to observe it – just go out and look up. If it’s a clear night why not take a photo and post it on the Moon Zoo forum? We’d love to see it. However if it is cloudy don’t worry as there are still plenty of things you can do to celebrate IOTMN. Why not spend an hour or so measuring craters or matching boulders in Moon Zoo? If you use Facebook have you discovered the excellent Moon Zoo app? The more you classify on Moon Zoo the more features you can unlock on the app starting with the most common to the rarest features on the Moon. You can learn about the features as as you collect them and even share them with your friends. The app also tells you how many classifications you have done! Did you know there’s also a Facebook Moon Zoo page? Over 400 people like it already. Let’s see if we can add some more on Saturday! And if you use Twitter why not follow @moonzoo and keep up with the latest news?

So whether it’s cloudy or clear why not make IOTMN your night to get more involved with the Moon – and Moon Zoo?

Jules is a volunteer moderator for the Moon Zoo forum