The SLOOH Interface

SLOOH is a robotic observatory on the Canary Islands. Every Monday, whenever conditions permit viewing, you can participate in multiple SLOOH "missions" over the course of an hour-long session.

What does SLOOH stand for? Apparently it's about putting the OOH into SLEW!

High atop Mount Teide, on Tenerife in the Canary Islands, the telescopes of SLOOH stand nestled among the facilities of a professional astronomical observatory. SLOOH is a subscription-based web site that streams live images of dozens of celestial objects viewed by its telescopes each clear night over the Internet.

SLOOH currently uses several 3-megapixel CCD cameras and four telescopes (in two domes):

  • a 14-inch diameter Schmidt Cassegrain Telescope (focal length 2160mm) high magnification scope and and Wide Field Lens System with a focal length of 135mm at f/5.6 in Dome 1
  • 14-inch diameter Schmidt Cassegrain Telescope (SCT) with a focal length of 4,000 mm, and an 85-mm diameter APO refractor telescope with a focal length of 480 mm in Dome 2
  • Paid: If you are ready to do more than join missions but want to lead them, take more photos, and share your results with friends and family, then consider upgrading to a Commander account:

    Monthly: $5.95 per month

    6 Months: $29.95

    12 Months: $49.95

    Commander level ($99.95 per year) gives you unlimited access to group missions and the ability to log on any time you like during mission hours. You can also schedule the telescopes to point to objects you select.

    Explorer level: ($29.95) lets you go on missions to 100 of your favorite celestial objects.

    Observer level: ($4.95) lets you go on missions to 10 of your favorite objects.

    To guarantee its visitors only the best experience, SLOOH tests the speed of your Internet connection and accepts only visitors with connection speeds of 40 kbps (40k) or greater.

SLOOH makes extensive use of the latest Macromedia Flash Player, a web-browser plug-in. Before you arrive at their interface, SLOOH checks to see if your browser has the latest Flash Player installed and directs you to download it if you do not.

Learn About Membership


While missions are running, SLOOH's operators often chat with visitors in the SLOOH Chat Room. You can join them if you have AOL's Instant Messenger (AIM) software installed. This is an optional feature only. For details, click the Chat button on the mission interface.

If you arrive early, the mission will start automatically at the scheduled time. If you arrive while the mission is running, you will join it in progress.

SLOOH also run a Users Group on Yahoo at: so you can check out what people have to say about it.

Mount Teide onTerife in the Canary Islands. © Gary Nugent


SLOOH 2 went live on March 18th, 2006. A year in the making, this version has been inspired its users' commitment to live astronomy. In addition to existing features, SLOOH 2 offers some bold and novel new elements that will attract an even greater membership from around the globe.

SLOOH 2.0 is designed to empower its users (from over 60 countries) to share their enthusiasm for astronomy with the greater public. Foremost among the changes is the new Member Channel, which enables members to broadcast their solo missions to the rest of the viewing membership. A new desktop alert system was also introduced, which notifies members when special missions are lined up with a live host who will narrate specifically about the celestial object in view.

Another new feature is SLOOH Radio which broadcasts live spoken audio during missions, and features leading astronomy experts, such as David Levy, co-discoverer of Comet Shoemaker-Levy, and Bob Berman of Astronomy Magazine. Speakers will respond to your questions while they show you their favorite celestial objects.

There's also a new SLOOH forum at:


With SLOOH, you have powerful telescopes at your disposal. Regardless of the quality of your own local skies, SLOOH looks deep into the clear dark skies over the Canary Islands. So get on board and look deep into to the heart of the cosmos yourself.

To whet your appetite, here are a couple of images I snapped with SLOOH:

M42 in Orion

M103 Open Cluster in Cassiopeia

Filed under: Astronomy Product Reviews