Recent Projects

Atmosphere and mantle composition

Magma flow in super-Earths

Rocky planets of similar size and larger than Earth are expected to undergo internal geochemical reactions that promote oxidized secondary atmospheres rich in water and carbon dioxide. But chemical exchange timescales between magma ocean interiors and equilibrated atmspheres may change this simplified picture. I show that the highly turbulent magma circulation regime in the interiors of sub-Neptunes may preserve initially reduced mantle compositions inherited from planetary formation, which affects the climate states we can expect to find with exoplanet surveys.
[Lichtenberg / ApJL, 2021]

Decarbonizing rocky exoplanets

Timing carbon loss during planet formation

Carbon compounds are essential for climate stability and power the chemistry of life, but they are strongly depleted on the terrestrial planets. We quantify carbon depletion during the primary accretion phase to establish observational predictions that may isolate extrasolar planetary systems with similar devolatization trends as the Solar System. Our work highlights how timing can crucially influence carbon fractionation during planet formation.
[Lichtenberg & Krijt / ApJL, 2021]

Atmosphere formation

Magma ocean diversity on exoplanets

Our own world started out as a literal hell — at the onset of the ‘Hadean’ eon the Moon-forming impact melted and vaporized large parts of the adolescent Earth. The resulting ‘magma ocean’ cooled down over a few million years, eventually allowing the water vapor in the atmosphere to rain out and form the earliest oceans not too long after the last giant collision — or so the story goes, according to the combined picture from geochemical, astronomical, and planetary science studies. But does this story hold equally well for other planets, such as Venus, Mars, or even rocky planets in other, extrasolar planetary systems?
[Lichtenberg, Bower, Hammond, Boukrouche, Sanan, Tsai, Pierrehumbert / JGR Planets, 2021]

Origin of the Solar System

Composition of planetary building blocks

The earliest history of the Solar System is inscribed in meteorites and the present-day structure of the inner terrestrial and outer gaseous and ice-rich planet population. We developed a new theory that explains our own home planetary system as the result of formation in two distinct episodes. This sets the inner and outer planets on divergent evolutionary paths already during the accretion of the proto-Sun and reinterprets the origins of the Earth’s earliest atmosphere and oceans.
[Lichtenberg, Drążkowska, Schönbächler, Golabek, Hands / Science, 2021]

Volatile delivery

Formation and distribution of extrasolar ocean worlds

Stochasticity during formation and the variety in exoplanet compositions suggest that the majority of rocky exoplanets are covered in global water layers – ocean worlds. In this project we demonstrate that variations in short-lived radionuclides across planetary systems – such as 26Al in the early Solar System – can prohibit this fate. By dehydrating water-rich planetesimals via outgassing, short-lived radionuclides desiccate forming terrestrial worlds and can generate planetary systems with balanced volatile abundances.
[Lichtenberg, Golabek, Burn, Meyer, Alibert, Gerya, Mordasini / Nature Astronomy, 2019]

Science Communication

Comic exhibition

Expedition Solar System

A comic exhibition centered on Solar system and space exploration that ran from 2018–2019. Research projects were presented in comic format for the interested public and for use in classrooms.

Blogging

Astrobites

From 2014–2016 I was a monthly contributor to the popular Astronomy blog Astrobites (~200k readers/yr). Until 2019 I remained active in the Astrobites community in administrative and supportive roles, covering hiring of new authors, internal communication, public relations, and devising strategies for extension and future development of the Astrobites network.