Carl A. Schmidt

Planetary Science

schmidtc @
Curriculum Vitae
PhD Thesis
Recent Talks


I'm a research scientist at the Boston University Center for Space Physics studying tenuous planetary atmospheres, also known as exospheres. Prior, I was a post-doc at CNRS/LATMOS, where I maintain a joint appointment, and a post-doc at University of Virginia. This site contains scattered bits of information about my various projects.


Atmospheres of the bodies below are being actively studied using the Rapid Imaging Planetary Spectroagraph (RIPS), a new instrument built here at Boston University. It's currently installed on the AEOS 3.7m telescope at Haleakala. More about RIPS


Mercury's atmospheric content is comparable to the air in a small building, spread over the whole planet. Still, the extreme brightness of the sodium and potassium D emission lines are easily observed via small ground-based telescopes. Interpreting such observations, alongside the extensive MESSENGER dataset, however requires complex numerical models and so their development is one of my main projects. More on Mercury


Cometary atmospheres are rich in complexity. Using an integral field spectrograph, I've studied the composition, structure, and dynamics of Comet C/2012 S1 (ISON), which, well. . . fell into the Sun. Then I worked with the STEREO spacecraft to study striae formation in Comet C/2011 L4 (Pan-STARRS). Now I'm onto another comet, 46P/Wirtanen, which will make a pass near Earth in December 2018.


Jupiter's volcanic moon Io is certainly one of the most interesting object's in our Solar System. I use infrared wavelengths to study volcanoes on its surface, various telescopes to observe its atmospheric changes and escape, and a spectrograph at Apache Point Observatory to track a wobbly doughnut orbiting Jupiter called the Io Plasma Torus. Current work revolves around coordinated datasets using RIPS, Hubble's Cosmic Orgins Spectrograph and Apache Point. I also lead some ground-based telescope efforts for Juno mission support related to Io studies.


Io can potenitally transfer some of its massively extended atmosphere to an adjacent moon, Europa. I'm currently working on a better understanding of the fraction of the sodium in Europa's atmosphere that is transferred from Io, rather than of native origins. Addressing this question ultimately helps solve another; what is the salinity of Europa's subsurface ocean?


Earth's moon also has a sodium atmosphere similar to Mercury's. During the LCROSS impact, colleagues at McDonald Observatory recorded a time series of a plume of sodium extending some 200 km above the impact site. A simulation of these data is in the works, for comparison with Mercury where no sodium signature of the MESSENGER impact was observed. RIPS also took some really interesting data of the lunar atmosphere during its comissioning at Lowell Observatory last March and this model is going to be critial in interpreting those results. More about the Moon's atmosphere