Broadcast 2723 Zolt Levay

20 Jun 2016 Zoltan (Zolt) Levay
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Guest:  Zoltan (Zolt) Levay; Topics:  Hubble Space Telescope (HST), images, archives, operations and more. Also the JWST.  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website,   Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See

We welcomed Zoltan (Zolt) Levay to the show to discuss the Hubble Space Telescope operations, imagery, and much more.  During our single segment 97 minute program, Mr. Levay started our discussion by saying that Hubble has observed over 1.2 million objects over its 26 year history.  Mr. Levay then talked about the process used to get time on Hubble for observing. It is a very competitive process.  Note that it takes about 90 minutes for Hubble to make an orbit and time is reserved on Hubble based on the number of orbits of the telescope.  A unit is an orbit.  Also note that there is no real viewing with Hubble. Everything is virtual.  The researcher remains at his or her prime location and a computer program is sent up to Hubble that carries out the specific observing protocol.  Our guest then talked about getting data back and image processing. 

A listener asked our guest about his favorite image or images. Zolt mentioned the Hubble Deep Field images and he explained how they were made.  The original Deep Field image was made in 1995.  He said that Hubble was able to expose small points in the sky, very feint objects by exposing for longer periods of time. 

Listener Sally wanted to know about the James Webb Space Telescope (JWST). Our guest said that JWST was to be complimentary to the HST and they hoped that Hubble would continue to operate while JJWST was operating.  We have an upcoming guest on the show in a few weeks to discuss the JWST.

Paul in Los Angeles wanted to know about Hubble limitations.  Zolt did go through several of the Hubble limitations and why they are limitations.  He mentioned the Moon, Venus, Mercury and a few other objects. 

Our guest had much to say about the HST images and the archives for them which are public with free access.  He mentioned as well as Hubble MAST ( and the Hubble Legacy Archive ( 

Another question came in from Wane who wanted to know how Hubble remained clean in space.  Our guest had much to say about this as keeping the telescope serviceable is complex. He talked about the mirror and the more serious issue of impacts on the telescope.  He also talked about the ability to reposition the telescope to avoid being hit but note the orbit of Hubble does not change. 

Several listeners wanted to know how Hubble works.  Our guest went into some detail to explain the reaction wheels, the Y, & Z axis, the gyroscopes and the accuracy of Hubble with 7,000ths of an arc second!

Near the end of our program, a listener asked Zolt about being with Hubble when it was announced there would be no Hubble rescue mission.  He wanted to know what was going on with the Hubble team at that time.  Zolt had much to say about the mood and what people thought when they believed there would be no Hubble rescue.  He also described how things changed when the rescue mission was finally announced.  Don't miss all of what our guest had to say in response to this question.

Another listener asked our guest about the color field seen by Hubble as compared to what humans can see and wondered if the images were "doctored" in anyway.  Zolt explained the color field that Hubble uses which is far broader than what humans can see.  He had much to say about Hubble images, what the human eye can see, and what they expect from JWST images.  This is a great discussion, don't miss it!

As the program was ending, we talked about ground based telescopes and what they can do that Hubble can't do and how all our telescope systems work complimentary to one another.  We included amateur astronomers and their smaller scopes in this discussion.  Don't miss this ending discussion. 

Please post your comments/questions in the comments section for this archived show on TSS blog.  You can reach Mr. Levay through me or the Space Telescope Science Institute.




Hubble’s public imagery

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