Google Sky : gateway drug

September 30, 2007

I just came back from the twice yearly Virtual Observatory Geeks meeting, otherwise known as the IVOA interoperability workshop. I am on the Exec, which means of course other people do the work and we pontificate a lot. We approved eight standards. Progress ! In an “Applications Showcase” session there were several talks on Google Sky and its possibilities, including one from Ryan Scranton, who created the beast together with Andy Connolly, while on special leave from Pittsburgh U. where they worked on a NASA predecessor called “NASA Worldwind“.

Obviously Google Sky is wonderful fun for Joe Public, and kinda cool for many amateur astronomers, but is it of any interest to professional astronomers ? Ryan thought yes – he said he thought of it as a cannabis-like “gateway drug” which many pros would play with, and then find themselves sucked into the crack-cocaine world of cone-searches, ADQL queries, workflows and so on. So where is the link ? Well several other VO stalwarts have already found ways to do VO-Google-Sky mashups of various kinds.

Example One is VOEvent. This is an IVOA protocol which gives a standard way to pass round messages from alerts made by gamma ray burst satellites, NEOs spotted by small telescopes, etc. There is a service run out of Caltech called “VO event net” which feeds these messages in various formats. Roy Williams showed they can be spat out as KML and so appear as push pins on your Google Sky.

Example Two is the PLASTIC Hub. This is a method which allows VO tools to interoperate, so that for example when you have found an image using Astroscope (from AstroGrid) you can pass it straight to Aladin (from CDS). Alasdair Allan showed how you can PLASTICise Google Sky, so that if you select a flagged object it will automatically move the cursor to the right place in the image you have open in Aladin, or whatever.

This is all very cute but I am still sure how useful it is. And as Bob Hanisch stressed a couple of times, Google Sky starts to get very confusing, and ambiguous, once you have a lot of stuff overlaid. Does this matter, if it is primarily fun for families, or Ryan’s gateway drug ? Well maybe suggested Bob, as high school teachers and kids are likely to start relying heavily on Google Sky.

By the way, there are alternatives, present or imminent. Wiki Sky performs a similar function, and is very good. ESO have a plan to use the excellent Stellarium planetarium software as a front end for VO tools. And Microsoft have been working for ages on a Google Sky equivalent, called the World Wide Telescope. Its one of the things Jim Gray was working on before he disappeared. I would never have guessed this a few years back, but I am starting to feel almost sorry for Microsoft. They have had a Google Earth equivalent for ages but it just hasn’t had the PR success of Google Earth. It was launched as “Virtual Earth” but then last year re-branded as part of “Live Search“. Its fast as well as well designed, and has an optional 3D interface.