GSC Logan Club Series: Dr. Linda T. Elkins-Tanton

Thursday, January 23, 2014

11:30 AM

3120 Herzberg (HP), Carleton University

Five Great Mysteries from the First 10 Myr of the Solar System

To begin to understand what makes a planet habitable, and thus where to look for life both within and outside of Earth’s solar system, we need to understand what in planetary formation and what in its subsequent evolution combine to produce a habitable planet. Though many things may help to make a habitable planet, only one thing is indispensible: liquid water. We will track water through the process of building planets, and along the way touch on these five major mysteries:

  1. How do dust grains in the disk around a young star accrete into rocky bodies that can form planets?
  2. Could planet formation processes make metal planets, in addition to rocky, icy, and gas planets?
  3. Where did the Earth’s water come from?
  4. Why aren’t there more moons?
  5. Can we still think our solar system is an average solar system, or do observations of exoplanets show ours is an unusual place?

Tracking water through planet formation requires information not just from the Earth and other planets in our solar system, but from meteorites, observations of exoplanetary systems, and from theory. Together with new data from missions to Mercury, the Moon, and Mars, more of these questions are being answered. Water on both the Earth and Mars seems to have come from rocky material like asteroids, and mission data shows that giant accretionary impacts do not dry out their planets. Thus, rocky planets everywhere have a good chance of forming with water oceans, and of being habitable, at least for a while.