International Workshop On Comets In Honor of Hans Rickman

Session

The physics of comets

18 mai 2016, 12:00

Amphitheater Building 18 (Meudon site)

Présidents de session

The physics of comets

• Nicolas Biver

The physics of comets

• Małgorzata Królikowska

The physics of comets

• Małgorzata Królikowska

6. Comets as collisional fragments of larger planetesimals

Dr alessandro morbidelli (OCA)

18/05/2016 12:00

The physics of comets

Talk

Comets are often thought of as "pristine planetesimals". However, most cometary objects that we study are just a few km in size. Planetesimals this small are highly unlikely to be pristine planetesimals. In fact, the collisional environment in the trans-Neptunian planetesimal disk was very severe both before and during the giant planet instability phase that formed and sculpted the current...

15. A concurrent comet and TNO formation scenario

Dr Bjorn Davidsson (Uppsala university)

18/05/2016 14:15

The physics of comets

Talk

For decades, comet scientists have debated whether comet nuclei are primordial rubble piles, formed at their current sizes through gentle accretion in the Solar Nebula, or if they are collisional rubble piles formed in the aftermath of violent collisions between larger parent bodies. The Rosetta mission to comet 67P/Churyumov-Gerasimenko and the Stardust sample-return mission to comet...

12. The chemical diversity and isotopic ratio in comets

Nicolas Biver

18/05/2016 15:00

The physics of comets

Talk

For the last 3 decades, infrared and especially microwave techniques have enabled the detection of up to 26 different parent molecules in the coma of comets. Several molecules have been detected in over 40 different comets. A large diversity of composition is seen in the sample, comprising comets of various dynamical origin. Abundances relative to water for the molecules can vary by a...

24. Surface properties of small icy bodies

Maria Antonietta Barucci (LESIA - Paris Observatory)

18/05/2016 16:15

The physics of comets

Talk

The study of the small bodies that orbit the Sun beyond Neptune, the transneptunian objects, has completely changed our view of the Solar System. The last decade, a huge quantity of data has been obtained by ground large telescopes and by space missions. Various surface compounds have been detected, including ices of water, methane, nitrogen, methanol, ethane and ammonia. An overview for all...

17. Anisotropic gas emission and non-uniform density distribution in a cometary coma

Slawomira Szutowicz (Space Research Centre)

18/05/2016 17:00

The physics of comets

Talk

In comets the anisotropic gas emission from their nuclei have been discovered in gas jets, fans, close-up images of cometary nuclei provided by missions, asymmetric shapes of the cometary gas production curves with respect to perihelion, asymmetric non-gravitational forces perturbing the cometary orbits and finally in the spectral imaging of comets in the molecular lines. The evidence of...