Jean-Luc Margot (original) (raw)

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Belgian-born astronomer and professor

Jean-Luc Margot (born 1969) is a Belgian-born astronomer and a UCLA professor with expertise in planetary sciences and SETI.

Margot has discovered and studied several binary asteroids with radar and optical telescopes. His discoveries include (87) Sylvia I Romulus, (22) Kalliope I Linus, S/2003 (379) 1, (702) Alauda I Pichi üñëm, and the binary nature of (69230) Hermes.

In 2000, he obtained the first images of binary near-Earth asteroids and described formation of the binary by a spin-up process.[1][2] Margot and his research group have studied the influence of sunlight on the orbits and spins of asteroids, the Yarkovsky and YORP effects.[3][4][5]

In 2007, Margot and collaborators determined that Mercury has a molten core from the analysis of small variations in the rotation rate of the planet.[6][7] These observations also enabled a measurement of the size of the core based on a concept proposed by Stan Peale.[8][9]

In 2012, Margot and graduate student Julia Fang analyzed Kepler space telescope data to infer the architecture of planetary systems.[10] They described planetary systems as "flatter than pancakes."[11] They also showed that many planetary systems are dynamically packed.[12]

Margot proposed an extension to the IAU definition of planet that applies to exoplanets.[13][14]

Between 2006 and 2021, Margot and collaborators measured the spin of Venus with a radar speckle tracking technique. They measured the orientation and precession of the spin axis. They also measured the duration of the length of day and the amplitude of length-of-day variations, which they attribute to transfer of momentum between the atmosphere and the solid planet.[15][16]

Since 2016, he has conducted searches for technosignatures using large radio telescopes with UCLA students.[17][18] Volunteers can contribute to SETI through the "Are we alone in the universe?" citizen science collaboration.[19]

Margot was awarded the H. C. Urey Prize by the American Astronomical Society in 2004.[20] The asteroid 9531 Jean-Luc is named after him.[21]

1. ^ "Some Asteroids Have Astronomers Seeing Double". JPL press release. 11 April 2002. Archived from the original on 17 July 2012. Retrieved 10 November 2015.
2. ^ Margot, Jean-Luc; et al. (2002). "Binary Asteroids in the Near-Earth Object Population". Science. 296 (5572): 1445–1448. Bibcode:2002Sci...296.1445M. doi:10.1126/science.1072094. PMID 11951001. S2CID 8768432.
3. ^ "Prediction Proved: Light Speeds Up an Asteroid as it Spins". The New York Times. 13 March 2007.
4. ^ Taylor, Patrick; et al. (2007). "Spin Rate of Asteroid (54509) 2000 PH5 Increasing due to the YORP Effect". Science. 316 (5822): 274–277. Bibcode:2007Sci...316..274T. doi:10.1126/science.1139038. PMID 17347415. S2CID 29191700..
5. ^ Greenberg, Adam H.; Margot, Jean-Luc; Verma, Ashok K.; Taylor, Patrick A.; Hodge, Susan E. (7 February 2020). "Yarkovsky Drift Detections for 247 Near-Earth Asteroids". The Astronomical Journal. 159 (3): 92. arXiv:1708.05513. Bibcode:2020AJ....159...92G. doi:10.3847/1538-3881/ab62a3. S2CID 119502545.
6. ^ "Mercury's spin reveals molten, not solid core". Reuters. 3 May 2007.
7. ^ Margot, Jean-Luc; et al. (2007). "Large longitude libration of Mercury reveals a molten core". Science. 316 (5825): 710–714. Bibcode:2007Sci...316..710M. doi:10.1126/science.1140514. PMID 17478713. S2CID 8863681.
8. ^ Peale, S. J. (1976). "Does Mercury have a molten core?". Nature. 262 (5571): 765–766. Bibcode:1976Natur.262..765P. doi:10.1038/262765a0. S2CID 4210179.
9. ^ Margot, Jean-Luc; et al. (2012). "Mercury's moment of inertia from spin and gravity data". Journal of Geophysical Research. 117: n/a. Bibcode:2012JGRE..117.0L09M. doi:10.1029/2012JE004161.
10. ^ Fang, Julia; Margot, Jean-Luc (2012). "Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity". The Astrophysical Journal. 761 (2): 92. arXiv:1207.5250. Bibcode:2012ApJ...761...92F. doi:10.1088/0004-637X/761/2/92. ISSN 0004-637X. S2CID 20234144.
11. ^ "Most Alien Solar Systems Are 'Flatter Than Pancakes'". Space.com. 15 October 2012.
12. ^ Fang, Julia; Margot, Jean-Luc (2013). "Are Planetary Systems Filled to Capacity? A Study Based on Kepler Results". The Astrophysical Journal. 767 (2): 115. arXiv:1302.7190. Bibcode:2013ApJ...767..115F. doi:10.1088/0004-637X/767/2/115. ISSN 0004-637X. S2CID 53706876.
13. ^ "Why we need a new definition of the word 'planet'". Los Angeles Times. 14 November 2015.
14. ^ Margot, Jean-Luc (1 December 2015). "A Quantitative Criterion for Defining Planets". The Astronomical Journal. 150 (6): 185. arXiv:1507.06300. Bibcode:2015AJ....150..185M. doi:10.1088/0004-6256/150/6/185. S2CID 51684830.
15. ^ Crockett, Christopher. "How long is a day on Venus? Scientists crack mysteries of our closest neighbor". phys.org.
16. ^ Margot, Jean-Luc; Campbell, Donald B.; Giorgini, Jon D.; Jao, Joseph S.; Snedeker, Lawrence G.; Ghigo, Frank D.; Bonsall, Amber (July 2021). "Spin state and moment of inertia of Venus". Nature Astronomy. 5 (7): 676–683. arXiv:2103.01504. Bibcode:2021NatAs...5..676M. doi:10.1038/s41550-021-01339-7. S2CID 232092194.
17. ^ "Researchers Just Scanned 14 Worlds From the Kepler Mission for "Technosignatures", Evidence of Advanced Civilizations". Universe Today. 15 February 2018.
18. ^ Margot, Jean-Luc; Li, Megan G.; Pinchuk, Pavlo; Myhrvold, Nathan; Lesyna, Larry; et al. (1 November 2023). "A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15–1.73 GHz". The Astronomical Journal. 166 (5): 206. arXiv:2308.02712. Bibcode:2023AJ....166..206M. doi:10.3847/1538-3881/acfda4.
19. ^ "UCLA is asking for the public's help in finding signs of extraterrestrial intelligence". Los Angeles Times. 15 February 2023.
20. ^ "Harold C. Urey Prize in Planetary Science". Division of Planetary Sciences of the American Astronomical Society. Retrieved 11 December 2021.
21. ^ "Small Body Orbital Elements 9531 Jean-Luc (1981 QK)". JPL. Retrieved 11 December 2021.

• Department of Earth, Planetary, and Space Sciences, UCLA
• Department of Physics and Astronomy, UCLA
• Personal web page