Pedro H. A. Hasselmann

Carioca, Brazilian and Astronomer. Living in Paris, France since 2016. I postdoctoral researcher in Italy at the INAF-Osservatorio Astronomico di Roma since 2021.

Major scientific interest: The photometric behavior of surfaces of the Small Bodies of the Solar System.

Did you know that for a few dozens of minutes every few years the brightness of Moon almost doubles? This phenomenon happens at Full Moon and is related to the Opposition Effect, an anomalous non-linear increase in brightness. It was attested by Dr. T. Gehrels in 1956 when studying the phases of asteroids and is also verified for many other atmosphereless bodies in the Solar System. The effect arises from the  distribution and optical properties of grains covering the surface of those bodies. It can also be verified on Earth over sand beaches, canopy of trees and soil, for example.

In my past and actual research, I studied this same phenomenon happening for the asteroid (21) Lutetia, the cometary nucleus of 67P/Churyumov-Gerasimenko, and the Near-Earth Asteroid Bennu. I work with reconstructing their phase curves (see below) using body-resolved space mission images to derive hints of the micro-physical state of their surface grains.

International and Brazilian Collaborations:

• ASI/LICIACube and NASA/DART (2021-). DRACO & LUKE/LEIA instruments.

• JAXA/Hayabusa 2 (2018-). NIRS3 & ONC instruments.

• NASA/OSIRIS-REX (2018-). OVIRS & OCAMS instruments. www.asteroidmission.org.

• OSIRIS/ESA/Rosetta camera team (2014-2018). Principal Investigator: Sierks, H (MPS-Germany). https://planetgate.mps.mpg.de/

• VIRTIS/ESA/Rosetta instrument team (2017-2018). Principal Investigator: Capaccioni, F (IAPS-Italy). http://virtis-rosetta.lesia.obspm.fr/VIRTIS-the-instrument.html

• NEOSHIELD (2016). EU/Horizon 2020 Project. http://www.neoshield.eu/science-technology-asteroid-impact/

• IMPACTON - Observatório Nacional (2009-2013). Principal Investigator: Daniela Lazzaro (ON-Brazil). http://www.on.br/impacton/

Past and current postdoctoral research positions:

• Current (since 10/2021) : INAF-Osservatorio Astronomico di Roma, Italia. Supervisor: E. Dotto.

• 11/2018. DIm-ACAV. Supervisor: S. Fornasier (OBSPM-France).

• 03/2017. DOMAINE D'INTÉRÊT MAJEUR EN ASTROPHYSIQUE ET CONDITIONS D'APPARITION DE LA VIE. LESIA- Observatoire de Paris-Meudon (https://dimacav.obspm.fr/). Supervisor: Barucci, M. A (OBSPM-France).

• 02/2016-02/2017. NEOSHIELD-2. LESIA- Observatoire de Paris-Meudon. Supervisor: Barucci, M. A.

• 10/2015-01/2016. Observatório Nacional. Supervisor: Lazzaro, D.

Degrees:

• PhD in Astronomy. Observatório Nacional, Brazil. 2015. Advisor: Lazzaro, D.

• PhD exchange program. LESIA-Observatoire de Paris-Meudon. 2013-2014. Supervisor: Barucci, M. A.

• MSc in Astronomy. Observatório Nacional, Brazil. 2011. Advisor: Lazzaro, D.

• BSc in Astronomy. Universidade Federal do Rio de Janeiro, Brazil. 2009.

Expertises:

• Phase curve & Bi-Directional Reflectance Distribution Function analysis.

• Small body surface properties & composition (VIS, NIR).

• Scientific computing. Multi-size data minimization.

• Advanced Python coder. From Numpy to Cython.

• Data structure and databases. SQL & HDF5.

• Approximate radiative transfer methods for packed discreet media (i.e., IMSA-Hapke, 2012; Van Ginneken, 1998;  Shkuratov et al., 2011).

• Image processing: body-resolved astronomical images; Image registration, geo-referencing, 3D-shape manipulation,  photo-topographic correction.

Talks available on-line:

• EPSC 2020, Online Conference. English.

• Pega a Visão with A. Ribeiro. Science outreach. Portuguese

• Missão OSIRIS-REx, Observatorio Nacional, RJ, Brazil. Portuguese.

• Missão Rosetta, Observatorio Nacional, RJ, Brazil. Portuguese.

• Scipy 2013, Austin, Texas, USA. English.