About Me

I study atmosphere-interior exchange on rocky planets, both within our Solar System and beyond. I'm interested in the initial outgassed atmospheres of rocky planets and their evolution with time due to external factors and due to interaction with the solid planet. During planet formation, all the materials that make a planet are intimately mixed together, so the physical and chemical processes of accretion and differentiation can have long term effects on the composition of both the atmosphere and the interior. I study these early processes using a combination of magma ocean, atmospheric and internal structure models. The presence of extant magma oceans on some hot rocky exoplanets provide a window into the early planet differentiation processes of the Solar System.

Full texts are available for all of my publications on my ResearchGate profile.

Contact Details

Laura Schaefer
Geological Sciences
Stanford University
450 Serra Mall
Bldg. 320 Rm.118
Stanford, CA 94305-2115

(650) 723-3090
lkschaef (at) stanford.edu


Harvard University

PhD in Astronomy & Astrophysics October 2016

Washington University in St. Louis

B.A. in Earth & Planetary Science May 2002


Stanford University

Assistant Professor Jan. 2019 - present

My group studies both Solar System objects and rocky exoplanets. We model atmosphere formation, internal structure and core formation, magma ocean processes including atmosphere-interior interactions and atmospheric escape, as well as specific planets and objects in the Solar System. Interested students should contact me directly about possible research projects and funding opportunities.

Arizona State University

Postdoctoral Scholar August 2016 - 2018

I studied magma ocean processes on the early Earth and other rocky bodies, including planetesimals. I also modeled the metallic asteroid Psyche in support of the Discovery class mission to visit that asteroid.

Washington University

Research Assistant June 2002 - July 2011

I worked as a research assistant following my undergraduate degree. I did thermochemical equilibrium modeling of many systems including: volcanic gases on Jupiter's moon Io, meteors in the Earth's atmosphere, trace elements in Venus' atmosphere, thermal metamorphism on meteorite parent bodies and outgassing of early planetary atmospheres.

Research Interests

Most of my research focuses on the interaction between volatiles and rocky materials on planetary bodies, which affects the formation and evolution of a planet's atmosphere and oceans. I started out working on Solar System objects like Io, Venus, meteorite parent bodies and the Earth. I have recently been really excited to apply similar models and techniques to the even wider variety of rocky exoplanets that have been discovered around other stars over the past few years.

Atmosphere of the Early Earth

The Earth's atmosphere has changed a lot since our planet formed. The present atmosphere is mostly made of nitrogen (N2) and oxygen (O2), but we know that O2 wasn't a major component of the atmosphere before about 2.5 billion years ago. Prior to that time, the atmosphere was probably mostly made out of N2 and CO2. However, there are no records of what the atmosphere was like during that time or earlier, so we have to rely on models to figure out what the atmosphere was made of in the earliest period of the planet (the time during which life first began). One way to approach this is to look at the kinds of materials that the Earth was made out of (e.g. meteorites) and try to calculate the composition of the atmospheres that they would produce when heated up, which simulates outgassing from a hot planetary interior.

Core Formation on super-Earths

Super-Earths - large rocky planets for which we have no analog in the Solar System - have much higher internal pressures than those found in the Earth. The effect of this higher pressure on the properties of mantle materials is mostly unconstrained, but may be significant. It's effect on viscosity may make mantle convection, and therefore heat transport and mantle outgassing, more sluggish. The high pressure may also effect chemistry in the deep interior which could hinder full interior differentiation into a silicate mantle and an iron core. Partitioning experiments at very high pressures indicate that the phase behavior that allows metal and silicate to separate during planetary differentiation may change behavior at pressures higher than those reached in the Earth's interior. Work on this issue is published in the Astrophysical Journal.

Ocean Formation and Planetary Thermal Evolution

The search for rocky exoplanets is essentially the search for possible habitable planets in other solar systems. However, astrobiologists believe that in order for life to originate on a planet, that planet must have liquid water (i.e., oceans). In our own Solar System, the Earth is the only example of a planet with surface oceans, but the presence of water on the surface is tied to our unique geological system of plate tectonics. On the Earth, volcanic outgassing of water from the mantle is balanced by loss of water to the mantle through subduction of water-rich oceanic seafloor. Much of this water is released immediately back to the surface through shallow, water-induced volcanism. However, a small but significant fraction of the water can be transported to deeper levels of the mantle. Mantle convection has therefore played an important role in controlling the size of Earth’s surface oceans over the planet’s lifetime.

The deep water cycle of Earth has been studied with parameterized convection models incorporating a water-dependent viscosity. The abundance of water in the mantle, which lowers the convective viscosity, evolves along with the mantle temperature. I have created a parameterized convection model that is extended to high pressures in order to study the deep water cycles of super-Earths. Assuming compositions similar to the Earth, our models indicate that ocean formation will be delayed on 5 MEarth planets by ~1 Gyr after planet formation. Although ocean mass on these planets increases with time, the oceans remain much shallower than for smaller planets, consistent with previous studies. Intermediate mass planets (2-4 MEarth) have immediate, but gradual outgassing and persistent oceans. Small terrestrial planets (≤ 1 MEarth) have rapid initial outgassing, but will gradually lose a significant fraction of their surface oceans due to mantle sequestration over their lifetimes.

Planetary Science Quotes

  • It is, however, a truism that no element of a complex system can ever be wholly isolated for study. In the present case, it is now very clear that the origin and composition of the atmosphere is intimately intertwined with the overall elemental composition, mineralogy, heat source strength, and melting and differentiation behaviour of the entire planet.

    John S. Lewis & Ronald Prinn, Planets and their Atmospheres: Origin and Evolution