Recently we’ve had some problems with access to the WISE and SDSS surveys (but not the SDSS DR7). We access these remotely using a standard protocol where we first find a list of the images in the region of interest and then download the ones we want. For WISE the initial queries were failing which meant that all WISE requests failed. We notified IPAC of the problem and they quickly rectified it.
For the SDSS the initial query for the list of images works fine, but if we try to download any image file the request fails. This means that some SDSS SkyView requests will succeed and some may succeed partially. SkyView caches the results from remote queries, so if anyone had requested a particular image previously, we don’t try to download it again, we just use our cached copy.
Both the SDSS and WISE data have been restored. It appears that the SDSS changed their output format several months ago so that SDSS queries that requested new regions have been failing for some while — but since we had rather large amount of data in the cache many SDSS queries succeeded.
The SDSS surveys are now pointing to DR9 data and since we do not have these cached SDSS queries will generally slow down as we rebuild our local cache.
Only the surveys labeled SDSSx are affected. The SDSS DR7 release which uses different servers and returns data in a somewhat different format, seems to be working without any problems. However it has somewhat less total sky coverage than the DR8 release.
The SDSS team are aware of the problems are are working to fix them. We apologize for any inconvenience to our users.