Old Equation May Shed New Light on Planet Formation

EXO WORLDS

Europa is a world that been shaped and reshaped over and over again by the massive tides Jupiter exerts over the moon.

by Mari N. Jensen
Tucson - Jan 12, 2004
New work with an old equation may help scientists calculate the thickness of ice covering the oceans on Jupiter's moon Europa and ultimately provide insight into planet formation.

Planetary bodies, such as the Earth and its moon, exert such gravitational force on one another that tides occur, not just in the oceans, but also in bodies of the planets themselves. The surfaces of planets actually rise and fall slightly as they orbit one another.

The standard for calculating how the gravity of one celestial body affects the shape of a second is an equation published in 1911 by A.E.H. Love. Sarah Frey, a doctoral candidate at the University of Arizona in Tucson, decided to see if she could figure out the thickness of ice on Europa by using Love's equation to calculate planetary tides.

"Love looked at two cases, which were very well behaved, very similar to Earth's values," she said.

However, Love didn't have the power of modern computers at his disposal.

Working with Terry Hurford, a graduate student in UA's department of planetary sciences and Richard Greenberg, a professor of planetary sciences at UA, Frey used computers to calculate what Love's equations predicted for various spheres that differed from one another in density, compressibility and rigidity. The spheres serve as proxies for planets.

To their surprise, the researchers found that in specific cases, the computer calculations suggested that the sphere would change shape dramatically. Frey said these special circumstances, called singularities, might ultimately reveal situations that would prevent the formation of planets.

Greenberg said, "If a rocky planet was a little bit bigger than Earth or Venus, it would be in the danger zone where the formula would predict a substantial distortion in the planet's shape. We're wondering if in some way this regulated the size of the planets."

Frey discussed the team's findings about Love's equations, "Characterization of instabilities in the tidal deformation of a planetary body," at the joint annual meeting of the American Mathematical Association and Mathematical Association of America (MAA) held last week.

EXO WORLDS

Suns Of All Ages Possess Comets, Maybe Planets

Atlanta - Jan 06, 2004
In early 2003, Comet Kudo-Fujikawa (C/2002 X5) zipped past the Sun at a distance half that of Mercury's orbit. Astronomers Matthew Povich and John Raymond (Harvard-Smithsonian Center for Astrophysics) and colleagues studied Kudo-Fujikawa during its close passage. Today at the 203rd meeting of the American Astronomical Society in Atlanta, they announced that they observed the comet puffing out huge amounts of carbon, one of the key elements for life. The comet also emitted large amounts of water vapor as the Sun's heat baked its outer surface.

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.