21.6 New perspectives on planet formation  (Page 4/22)

Key concepts and summary

The ensemble of exoplanets is incredibly diverse and has led to a revision in our understanding of planet formation that includes the possibility of vigorous, chaotic interactions, with planet migration and scattering. It is possible that the solar system is unusual (and not representative) in how its planets are arranged. Many systems seem to have rocky planets farther inward than we do, for example, and some even have “hot Jupiters” very close to their star. Ambitious space experiments should make it possible to image earthlike planets outside the solar system and even to obtain information about their habitability as we search for life elsewhere.

For further exploration

Articles

Star Formation

Blaes, O. “A Universe of Disks.” Scientific American (October 2004): 48. On accretion disks and jets around young stars and black holes.

Croswell, K. “The Dust Belt Next Door [Tau Ceti].” Scientific American (January 2015): 24. Short intro to recent observations of planets and a wide dust belt.

Frank, A. “Starmaker: The New Story of Stellar Birth.” Astronomy (July 1996): 52.

Jayawardhana, R. “Spying on Stellar Nurseries.” Astronomy (November 1998): 62. On protoplanetary disks.

O’Dell, C. R. “Exploring the Orion Nebula.” Sky&Telescope (December 1994): 20. Good review with Hubble results.

Ray, T. “Fountains of Youth: Early Days in the Life of a Star.” Scientific American (August 2000): 42. On outflows from young stars.

Young, E. “Cloudy with a Chance of Stars.” Scientific American (February 2010): 34. On how clouds of interstellar matter turn into star systems.

Young, Monica “Making Massive Stars.” Sky&Telescope (October 2015): 24. Models and observations on how the most massive stars form.

Exoplanets

Billings, L. “In Search of Alien Jupiters.” Scientific American (August 2015): 40–47. The race to image jovian planets with current instruments and why a direct image of a terrestrial planet is still in the future.

Heller, R. “Better Than Earth.” Scientific American (January 2015): 32–39. What kinds of planets may be habitable; super-Earths and jovian planet moons should also be considered.

Laughlin, G. “How Worlds Get Out of Whack.” Sky&Telescope (May 2013): 26. On how planets can migrate from the places they form in a star system.

Marcy, G. “The New Search for Distant Planets.” Astronomy (October 2006): 30. Fine brief overview. (The same issue has a dramatic fold-out visual atlas of extrasolar planets, from that era.)

Redd, N. “Why Haven’t We Found Another Earth?” Astronomy (February 2016): 25. Looking for terrestrial planets in the habitable zone with evidence of life.

Seager, S. “Exoplanets Everywhere.” Sky&Telescope (August 2013): 18. An excellent discussion of some of the frequently asked questions about the nature and arrangement of planets out there.

Seager, S. “The Hunt for Super-Earths.” Sky&Telescope (October 2010): 30. The search for planets that are up to 10 times the mass of Earth and what they can teach us.