I'm Joshua Peek
an astronomer and archive scientist at STScI.

I work on the diffuse universe and
improving science communication and productivity with archives.


We have moved from asking What is in the universe? to How did the those things come to be?
I try to answer this question by examining the diffuse phase of the universe. The story of every object in the universe can be simply told as "diffuse material became dense under the influence of gravity". My work aims to understand the flow of this diffuse material. To do this I use spectroscopic measurements of gas (chiefly the 21-cm line) as well as observations of the effects of dust obscuration. The spectroscopy helps me better understand the velocities of gas; the dust helps me understand where the enriched material is in our universe.


I lead the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) survey of neutral hydrogen in the Galaxy in the 21-cm line, which covers 13,000 square degrees at 4' resolution. DR1 is public; contact me about DR2, which covers the whole Arecibo sky.

Galactic Fibers

I explore and characterize diffuse, fibrous features in the neutral interstellar medium which we discovered with GALFA-HI. Their strongly magnetized character makes them powerful probes of the dynamic ISM.

Kinetic Tomography

I work on methods that combine data from 3D extinction maps with cubes from radio telescopes (CO, HI) in pursuit of 4D maps of the Galaxy.

STScI Archives

At STScI I work in the Archives, developing scientific functionality of the
Mikulski Archive for Space Telescopes .


I am leading an effort at STScI called MARC to better integrate our holdings with the literature using DOIs. Our new tool allows researches to easily find their own data, and assign it an unique, long-lasting identifier.


I lead STScI's Archive for WFIRST. WFIRST, launching in 2024, will be a physics experiment, a survey, and an observatory, and our archive must provide for users who use it in all of these many ways.


Science is storytelling. I tell scientific stories and help others do the same.

The "Paper" of the Future

With Alyssa Goodman I wrote an article describing and showcasing what as possible in digital publishing in astronomy.


I am assisting the AAS and STScI in transitioning the World Wide Telescope into a fully open source tool for the astronomical community

AAS Journals

I advise and assist the AAS Journals in providing enhanced digital storytelling tools for authors, including my service on the AAS Journals Task Force.


With Adrian Price-Whelan I developed methods for easily generating interactive figures for publications.

Public Lectures

I give award-winning public lectures!

Invisible Universe

In an Xperia Studio project I developed software for viewing the sky in wavelengths beyond the optical.


I advise PhD students at Columbia University and JHU.

Susan Clark

I advise Susan on her PhD work in neutral gas morphology in the ISM and magnetic fields.

Kirill Tchernyshyov

I advise Kirill on his PhD work developing the field of kinetic tomography using applied mathematics methods.

Yong Zheng

I advise Yong on her PhD work in the circumgalactic medium and the disk-halo interface.

About Me

I am married to the fabulous Katie Peek, and we reside in lovely Baltimore, Maryland. We have a son, Maxwell Peek, born 2012. If you have questions about my name, you can check out my name FAQ. I enjoy a number of activities beyond astrophysics. I am the emeritus technical director for the small theater company elastic future, and have designed many sets for small theaters and spaces in Cambridge, Princeton, and San Francisco. I am a veteran burner, having attended Burning Man in 2001 and from 2006 to 2011 and in 2015. I am a technical lead of gnomecamp, a NYC and SF-based themecamp at Burning Man. I enjoy rock climbing, and am mostly a gym rat, although I have bouldered in Yosemite, the Grand Tetons and around Berkeley. I have also been known to play Ultimate (frisbee) from time to time. These days I mostly just carry Max around.