Jonathan McDowell

Jonathan Christopher McDowell (born 1960) is an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. He is a staff member at the Chandra X-ray Center. McDowell is the author and editor of Jonathan's Space Report, an e-mail-distributed newsletter documenting satellite launches.

McDowell has a BA in Mathematics (1981) from Churchill College and a PhD in Astrophysics (1986) from the Institute of Astronomy, both at the University of Cambridge, England. After high school, McDowell worked for six months at the Royal Observatory, Greenwich and held a summer job at the Royal Observatory, Edinburgh before he began his PhD studies. His first post-doctoral position was at Jodrell Bank followed by another at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. McDowell then moved to Huntsville, Alabama, where he spent a year at NASA's Marshall Space Flight Center. In 1992, McDowell returned to Cambridge, Massachusetts, and currently works there as a staff member at the Chandra X-ray Center.

McDowell's main research interests include:

• the cosmological microwave background
• the X-ray emission from the merging galaxy Arp 220
• the nature of the broad emission line region in quasars
• the broad-band spectral energy distribution in quasars
• studying nearby galaxies with the Chandra X-ray Observatory

In software, McDowell helped design the CIAO data analysis package and the software infrastructure for the Chandra X-ray Observatory data processing pipelines. More recently, McDowell led the creation of an exhibit of astronomical images at the Smithsonian. He is co-director of an undergraduate summer research program whose alumni include Alicia M. Soderberg and Planet Hunters scientist Megan Schwamb .

In his free time, McDowell conducts research into the history of spaceflight, and since 1989 has written and edited Jonathan's Space Report, a free internet newsletter documenting technical details on satellite launches. This information, obtained from original sources including declassified Department of Defense documents and Russian-language publications, can also be found on McDowell's web site.

In 1994 McDowell published a history of the North American X-15 spaceplane, in which he suggested that 80 km should be adopted as the boundary of space.In the mesosphere, 80 km is nearly equal to 50 mi, the altitude used by the United States to confer astronaut status on pilots, as in the X-15 program itself.It also differs from the internationally accepted Kármán line altitude of 100 km, used by the Fédération Aéronautique Internationale for the same purpose.In 2018 McDowell published a refereed journal paper in Acta Astronautica making detailed physical arguments for the 80 km value.

From 1993 to 2010, McDowell wrote a monthly column for Sky and Telescope. In addition, McDowell has been interviewed on numerous television and radio programs with regard to rocket launches or other celestial phenomena that generated interest amongst the general public.

The main-belt asteroid 4589 McDowell was named after him in 1993.

In addition to his astronomical activities, McDowell has been engaged in progressive activism, for example Planned Parenthood, and other social endeavors such as promoting skepticism and atheism .