NLSI Director's Virtual Seminar Series with Hal Levison
Please join the NASA Lunar Science Institute for its Fall 2009 Director’s Virtual Seminar Series. The first seminar will be on TUESDAY, OCTOBER 20, 2009 at 9:00 AM Pacific.
TITLE: A Review of the Dynamical Models Associated with the Late Heavy
Bombardment
SPEAKER: Dr. Hal Levison, a member of the NLSI team from the Southwest Research Institute in Boulder, CO
ABSTRACT: Since the time of Apollo there has been a controversy over whether the youngest lunar basins formed as a result of the tail-end of terrestrial planet formation or as a result of an impact spike that occurred some 3.9G years ago. Historically, one of the difficulties with understanding such a late heavy bombardment (or LHB) was a lack of a dynamical mechanism that would suddenly release a large number of small bodies. In the last decade, however, we have learned that not only are the orbits of the planets formally chaotic, but that they might have changed significantly, and perhaps violently, since the planets formed. Such a redistribution of the planets' orbits would have naturally led to a release of small bodies from heretofore stable reservoirs and thus to a LHB on the Moon (and elsewhere). In this talk, I will review the current dynamical models of the early dynamical evolution of the Solar System, concentrating on the period near 3.9Ga. Mostly I will discuss the so-called Nice Model. In addition to supplying a natural explanation for the LHB, this model explains, for the first time, many of the observed characteristics of the Solar System, thereby placing the LHB in the context of the evolution of the system as a whole.
TO JOIN USING A VIDEOCONFERENCING SYSTEM:
Please RSVP to Delia Santiago (Delia.L.Santiago -at- nasa.gov) if you will be joining by Polycom. Do not connect to the teleconference if you will be joining by Polycom.
TO JOIN USING PHONE and WEB BROWSER: The slides for this meeting will be presented using Adobe Connect. To join the meeting, connect to http://nasa-nai.acrobat.com/nlsi_director_seminars/
The teleconference number will be displayed when joining the meeting.
SPEAKER: Dr. Hal Levison, a member of the NLSI team from the Southwest Research Institute in Boulder, CO
ABSTRACT: Since the time of Apollo there has been a controversy over whether the youngest lunar basins formed as a result of the tail-end of terrestrial planet formation or as a result of an impact spike that occurred some 3.9G years ago. Historically, one of the difficulties with understanding such a late heavy bombardment (or LHB) was a lack of a dynamical mechanism that would suddenly release a large number of small bodies. In the last decade, however, we have learned that not only are the orbits of the planets formally chaotic, but that they might have changed significantly, and perhaps violently, since the planets formed. Such a redistribution of the planets' orbits would have naturally led to a release of small bodies from heretofore stable reservoirs and thus to a LHB on the Moon (and elsewhere). In this talk, I will review the current dynamical models of the early dynamical evolution of the Solar System, concentrating on the period near 3.9Ga. Mostly I will discuss the so-called Nice Model. In addition to supplying a natural explanation for the LHB, this model explains, for the first time, many of the observed characteristics of the Solar System, thereby placing the LHB in the context of the evolution of the system as a whole.
TO JOIN USING A VIDEOCONFERENCING SYSTEM:
Please RSVP to Delia Santiago (Delia.L.Santiago -at- nasa.gov) if you will be joining by Polycom. Do not connect to the teleconference if you will be joining by Polycom.
TO JOIN USING PHONE and WEB BROWSER: The slides for this meeting will be presented using Adobe Connect. To join the meeting, connect to http://nasa-nai.acrobat.com/nlsi_director_seminars/
The teleconference number will be displayed when joining the meeting.
