 |
|
MIT finds young planets stay hotter longer
October 16, 2008Study shows newborn Earth-like planets could be easier to find
CAMBRIDGE, Mass. - Hot, young planets may be easier to spot because they stay that way longer than astronomers have thought, according to new work by MIT planetary scientist Linda Elkins-Tanton.
For a few million years after their initial formation, planets like Earth may maintain a hot surface of molten rock that would glow brightly enough to make them stand out as they orbit neighboring stars. Elkins-Tanton, Mitsui Career Development Professor of Geology in the Department of Earth, Atmospheric and Planetary Sciences, says the "magma ocean" stage for Earth-sized planets may last a few million years, much longer than previously estimated. "That means we may actually see them elsewhere, as detection systems get better," she said.
Elkins-Tanton presented her new findings this week at the annual meeting of the American Astronomical Society's Division for Planetary Sciences, being held this year in Ithaca, N.Y. The research shows that even after the surface magma solidifies, within about five million years, it could stay hot enough to glow brightly in infrared light for tens of millions of years, providing a relatively long window for detectability.
The big problem for astronomers hoping to detect planets around other stars is the vast difference in brightness between the star and the planet, which shines only by reflecting light from its parent star. But the difference in brightness in infrared wavelengths for a glowing, molten planetary surface would be much less, making the detection more feasible.
The long duration of the molten stage turns out to be the result of a two-stage process, Elkins-Tanton explained. The initial heating, generated by a combination of radioactivity in the planet's interior and the heat generated by the collision of millions of chunks of rock crashing together to form the planet, actually is quite short-lived: The planet's surface is expected to solidify quickly, within a few hundred thousand years, as originally thought. But then a secondary upheaval begins, in which heavier iron-rich material that has solidified at the surface begins to sink toward the core, causing other hotter material to rise to the surface.
This "overturn" process, it turns out, produces the much-longer-lived molten surface, lasting for millions of years, she said. Because the Earth's crust is so dynamic, there is no material left from that initial epoch that could be studied to test this modelling, she said, but on other planets such as Mars or Mercury there might be early remnant rocks that could be tested. The analysis also leads to specific conclusions about the surface composition of planets, so detection of certain specific minerals on Mercury, for example, which the MESSENGER spacecraft may be able to carry out when it begins its study of the planet in 2011, might support the theory.
In addition, the detection of hot, young planets around other stars, which might become possible over the next several years, might provide another line of evidence to support this conclusion, she said.
Massachusetts Institute of Technology
Elkins-Tanton presented her new findings this week at the annual meeting of the American Astronomical Society's Division for Planetary Sciences, being held this year in Ithaca, N.Y. The research shows that even after the surface magma solidifies, within about five million years, it could stay hot enough to glow brightly in infrared light for tens of millions of years, providing a relatively long window for detectability.
The big problem for astronomers hoping to detect planets around other stars is the vast difference in brightness between the star and the planet, which shines only by reflecting light from its parent star. But the difference in brightness in infrared wavelengths for a glowing, molten planetary surface would be much less, making the detection more feasible.
The long duration of the molten stage turns out to be the result of a two-stage process, Elkins-Tanton explained. The initial heating, generated by a combination of radioactivity in the planet's interior and the heat generated by the collision of millions of chunks of rock crashing together to form the planet, actually is quite short-lived: The planet's surface is expected to solidify quickly, within a few hundred thousand years, as originally thought. But then a secondary upheaval begins, in which heavier iron-rich material that has solidified at the surface begins to sink toward the core, causing other hotter material to rise to the surface.
This "overturn" process, it turns out, produces the much-longer-lived molten surface, lasting for millions of years, she said. Because the Earth's crust is so dynamic, there is no material left from that initial epoch that could be studied to test this modelling, she said, but on other planets such as Mars or Mercury there might be early remnant rocks that could be tested. The analysis also leads to specific conclusions about the surface composition of planets, so detection of certain specific minerals on Mercury, for example, which the MESSENGER spacecraft may be able to carry out when it begins its study of the planet in 2011, might support the theory.
In addition, the detection of hot, young planets around other stars, which might become possible over the next several years, might provide another line of evidence to support this conclusion, she said.
Massachusetts Institute of Technology
Planetary Science Current Events and Planetary Science News RSSA Lightning Strike in Africa Helps Take the Pulse of the Sun
Sunspots, which rotate around the sun's surface, tell us a great deal about our own planet. Scientists rely on them, for instance, to measure the sun's rotation or to prepare long-range forecasts of the Earth's health.
Cave Study Links Climate Change to California Droughts
California experienced centuries-long droughts in the past 20,000 years that coincided with the thawing of ice caps in the Arctic.
'Ultra-primitive' particles found in comet dust
Dust samples collected by high-flying aircraft in the upper atmosphere have yielded an unexpectedly rich trove of relicts from the ancient cosmos, report scientists from the Carnegie Institution.
Meteorite from September 25 fireball event recovered and presented
When Tony Garchinski heard a loud crash just after 9 p.m. on Friday, September 25 he didn't think much of it. That is, until he awoke the next morning to find the windshield of his mom's Nissan Pathfinder with a huge crack in it. Making note of the 'unusual' rocks he later found on the car's hood, Garchinski chalked the incident up to vandalism and filed a police report.
Western astronomers capture spectacular meteor footage and images
Astronomers from The University of Western Ontario have released footage of a meteor that was approximately 100 times brighter than a full moon. The meteor lit up the skies of southern Ontario two weeks ago and Western astronomers are now hoping to enlist the help of local residents in recovering one or more possible meteorites that may have crashed in the area of Grimsby, Ontario.
Alfalfa sprouts key to discovering how meandering rivers form and maintain
Sinuous, meandering streams produce diverse and wildlife-rich habitats and are the aim of many river restoration efforts, but until now, the bank, water flow and sediment conditions required to form and maintain meanders have been largely a matter of speculation.
Nullarbor fireball cameras find rare meteorite
Using cameras which capture fireballs streaking across the night sky and sophisticated mathematics, a world-wide team of scientists have managed to find not only a tiny meteorite on the vast Nullarbor Plain, but also its orbit and the asteroid it came from.
NASA Researchers Make First Discovery of Life's Building Block in Comet
NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.
How the moon got its stripes
A new study has revealed the origins of tiger stripes and a subsurface ocean on Enceladus- one of Saturn's many moons. These geological features are believed to be the result of the moon's unusual chemical composition and not a hot core, shedding light on the evolution of planets and guiding future space exploration.
Caltech scientists predict greater longevity for planets with life
Roughly a billion years from now, the ever-increasing radiation from the sun will have heated Earth into inhabitability; the carbon dioxide in the atmosphere that serves as food for plant life will disappear, pulled out by the weathering of rocks; the oceans will evaporate; and all living things will disappear.
More Planetary Science Current Events and Planetary Science News Articles
 |
Planetary Sciences by Imke de Pater (Author), Jack J. Lissauer (Author) Planetary Sciences presents a comprehensive coverage of this fascinating and expanding field at a level appropriate for graduate students and researchers in the physical sciences. The book explains the wide variety of physical, chemical and geological processes that govern the motions and properties of planets. Observations of the planets, moons, asteroids, comets and planetary rings in our Solar System, as well as extrasolar planets, are described, and the process of planetary formation is discussed. |
 |
Introduction to Planetary Science: The Geological Perspective by Gunter Faure (Author), Teresa M. Mensing (Author) This textbook is intended to be used in a lecture course for college students majoring in Earth Sciences. Planetary science provides an opportunity for these students to apply a wide range of subject matter pertaining to the Earth to the study of other planets and their principal satellites. In this way, planetary science tends to unify subjects in the Earth Sciences that are traditionally taught separately. Therefore, planetary science is well-suited to be taught as a capstone course for senior undergraduates in geology departments and as an introduction to the solar system in astronomy departments. Both groups of students will benefit because planetary science bridges the gap between geology and astronomy and it prepares geologists and astronomers to participate actively in the... |
 |
Planetary Science: The Science of Planets Around Stars by George H. A. Cole (Author), Michael M. Woolfson (Author) There are many planetary systems other than our own, but it is only through a detailed understanding of the relatively accessible bodies in our solar system that a thorough appreciation of planetary science can be gained. This is particularly pertinent with the recent discovery of extra-solar planets and the desire to understand their formation and the prospect of life on other worlds. Planetary Science: The Science of Planets Around Stars focuses on the structure of planets and the stars they orbit and the interactions between them. The book is written in two parts, making it suitable for students at different levels and approaching planetary science from differing backgrounds. Twelve independent descriptive chapters reveal our solar system and the diverse bodies it contains,... |
![Jbk Earth and Planetary Science [CD on Demand]](http://ecx.images-amazon.com/images/I/51Ql1xmOG6L._SL160_.jpg) |
Jbk Earth and Planetary Science [CD on Demand] by Jumping Bacteria Kids Jbk Earth and Planetary Science by Jumping Bacteria Kids This product is manufactured on demand using CD-R recordable media. Amazon.com's standard return policy will apply. |
 |
HARRY POTTER HOGWARTS TELESCOPE and ASTRONOMY SPACE SCIENCE - CELESTIAL STAR CHARTING and MAGICAL WORKING SKY VIEWING TELESCOPE CRAFT KIT by Troll Delta Kids Educational Materials Make Your Own Working Hogwarts Enchanted Telescope with Real Glass Lenses using Hogwarts Lab Materials and easy to follow instructions. We are featuring a New Sealed and Unopened Delta Troll Educational Media Harry Potter Spells and Potions Series Home & School Self Teaching Activity, Craft & Experiment Packet Titled: HARRY POTTER HOGWARTS SPELLS & POTIONS / ASTRONOMY, CELESTIAL STAR CHARTING, AND TELESCOPE CONSTRUCTION SPACE SCIENCE ACTIVITY KIT. From the Troll Delta SPELLS & POTIONS SERIES! Study the Stars, Planets, and Constellations / Make Your Own Sundial and more with Hogwarts approved materials, parts, components, and easy illustrated instructions. This ASTRONOMY & SPACE SCIENCE 10" X 13" kit Includes: Experiment and Activity Series Collector Lab Binder Pages, BiConclave... |
 |
Planetary Traveler Starring: Nathan House Directed By: Jan Nickman |
 |
Our Solar System (Planetary Information) Art Poster Print - 24" X 36" |
 |
A Space Viz Production - Planetary Defense Starring: Rusty Schweickart, David Morrison, Simon P. Worden, Freeman Dyson, David H. Levy, more.. Sir Arthur C. Clarke Directed By: Mark Moidel Also With: Mark Moidel (Writer), Space Viz Productions www.SpaceViz.com (Producer) Watch more clips of this movie, visit our site at www.SpaceViz.com "Planetary Defense" nominated for the prestigious 2008 Clarke Awards, the Oscars for Space Achievements. Fellow nominees include Sir Richard Branson, Professor Stephen Hawking and Ron Howard. Synopsis Who will save Earth? Scientists and the military have only recently awakened to the notion that impacts with Earth do happen. "Planetary Defense" meets with both the scientific and military communities to study our options to mitigate an impact from asteroids and comets, collectively known as NEO's (Near Earth Objects). "Civilization is ill prepared for the inevitable. It's not if an impact will happen with the Earth, it's when!" Mark Moidel's "Planetary... |
 |
Jbk Earth and Planetary Science Jumping Bacteria Kids (Primary Contributor) |
 |
Planetary Crusts: Their Composition, Origin and Evolution (Cambridge Planetary Science) by S. Ross Taylor (Author), Scott McLennan (Author) This is the first book ever published to explain how and why solid planets and satellites develop crusts. Written by two leading authorities on the subject, it presents a geochemical and geological survey of the crusts of the Moon, Mercury, Venus, Earth, Mars, the asteroid Vesta, and several satellites such as Europa, Ganymede, and Callisto. After describing how solar system bodies are formed, the authors compare the different planetary crusts and discuss current controversies on the subject. They introduce the theory of stochastic processes dominating crustal development, and debate the possibility of Earth-like planets existing elsewhere in the cosmos. Extensively referenced and annotated, this book presents an up-to-date survey of the scientific problems of crustal development, and is... |
| © 2009 BrightSurf.com |