Featured Research

from universities, journals, and other organizations

Planet-formation Model Indicates Earthlike Planets Might Be Common

Date:
December 11, 2003
Source:
University Of Washington
Summary:
Astrobiologists disagree about whether advanced life is common or rare in our universe. But new research suggests that one thing is pretty certain – if an Earthlike world with significant water is needed for advanced life to evolve, there could be many candidates.

Astrobiologists disagree about whether advanced life is common or rare in our universe. But new research suggests that one thing is pretty certain – if an Earthlike world with significant water is needed for advanced life to evolve, there could be many candidates.

In 44 computer simulations of planet formation near a sun, astronomers found that each simulation produced one to four Earthlike planets, including 11 so-called "habitable" planets about the same distance from their stars as Earth is from our sun.

"Our simulations show a tremendous variety of planets. You can have planets that are half the size of Earth and are very dry, like Mars, or you can have planets like Earth, or you can have planets three times bigger than Earth, with perhaps 10 times more water," said Sean Raymond, a University of Washington doctoral student in astronomy.

Raymond is the lead author of a paper detailing the simulation results that has been accepted for publication in Icarus, the journal of the American Astronomical Society's Division for Planetary Sciences. Co-authors are Thomas R. Quinn, a UW associate astronomy professor, and Jonathan Lunine, a professor of planetary science and physics at the University of Arizona.

The simulations show that the amount of water on terrestrial, or Earthlike, planets could be greatly influenced by outer gas giant planets like Jupiter.

"The more eccentric giant planet orbits result in drier terrestrial planets," Raymond said. "Conversely, more circular giant planet orbits mean wetter terrestrial planets."

In the case of our solar system, Jupiter's orbit is slightly elliptical, which could explain why Earth is 80 percent covered by oceans rather than being bone dry or completely covered in water miles deep.

The findings are significant because of the discovery in recent years of a large number of giant planets such as Jupiter and Saturn orbiting other suns. The presence, and orbits, of those planets can be inferred from their gravitational interaction with their parent stars and their affect on light from those stars as seen from Earth.

It currently is impossible to detect Earthlike planets around other stars. However, if results from the models are correct, there could be planets such as ours around a number of other suns relatively close to our solar system. A significant number of those planets are likely to be in the "habitable zone," the distance from a star at which the planet's temperature will maintain liquid water on the surface. Liquid water is thought to be a requirement for life, so planets in a star's habitable zone are ideal candidates for life. It is unclear, however, whether those planets could harbor more than simple microbial life.

The researchers note that their models represent the extremes of what is possible in forming Earthlike planets rather than what is typical of planets observed in our galaxy. For now, they said, it is unclear which approach is more realistic.

Their goal is to understand what a system's terrestrial planets will look like if the characteristics of a system's giant planets are known, Raymond said.

Quinn noted that all of the giant planets detected so far have orbits that carry them very close to their parent stars, so their orbits are completed in a relatively short time and it is easier to observe them. The giant planets observed close to their parent stars likely formed farther away and then, because of gravitational forces, migrated closer.

But Quinn expects that giant planets will begin to be discovered farther away from their suns as astronomers have more time to watch and are able to observe gravitational effects during their longer orbits. He doubts such planets will be found before they have completed whatever migration they make toward their suns, because their orbits would be too irregular to observe with any confidence.

"These simulations occur after their migration is over, after the orbits of the gas giants have stabilized," he said.

The research is supported by the National Aeronautics and Space Administration's Astrobiology Institute, its Planetary Atmospheres program, and Intel Corp.


Story Source:

The above story is based on materials provided by University Of Washington. Note: Materials may be edited for content and length.


Cite This Page:

University Of Washington. "Planet-formation Model Indicates Earthlike Planets Might Be Common." ScienceDaily. ScienceDaily, 11 December 2003. <www.sciencedaily.com/releases/2003/12/031211074826.htm>.
University Of Washington. (2003, December 11). Planet-formation Model Indicates Earthlike Planets Might Be Common. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2003/12/031211074826.htm
University Of Washington. "Planet-formation Model Indicates Earthlike Planets Might Be Common." ScienceDaily. www.sciencedaily.com/releases/2003/12/031211074826.htm (accessed July 23, 2014).

Share This




More Space & Time News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins