|
Topic Name: APL Astronomer Spies Conditions 'Just Right' for Building an Earth
Category: STAR (Space, Telecommunications & Radioscience)
Research persons: Dr. Carey Lisse
Location: 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
Details
An Earth-like planet is likely forming 424 light-years away in a
star system called HD 113766, say astronomers using
NASA's Spitzer Space Telescope.
Scientists have discovered a huge belt of warm dust - enough to
build a Mars-size planet or larger - swirling around a distant star that is just
slightly more massive than our sun. The dust belt, which they suspect is
clumping together into planets, is located in the middle of the system's
terrestrial habitable zone. This is the region around a star where liquid water
could exist on any rocky planets that might form. Earth is located in the middle
of our sun's terrestrial habitable zone.
At approximately 10 million years old, the star is also at just
the right age for forming rocky planets.
"The timing for this system to be building an Earth is very
good," says Dr. Carey Lisse, of the Johns
Hopkins University Applied Physics Laboratory, Laurel, Md. "If the system
was too young, its planet-forming disk would be full of gas, and it would be
making gas-giant planets like Jupiter instead. If the system was too old, then
dust aggregation or clumping would have already occurred and all the system's
rocky planets would have already formed."
According to Lisse, the conditions for forming an Earth-like
planet are more than just being in the right place at the right time and around
the right star - it's also about the right mix of dusty materials.
Using Spitzer's infrared
spectrometer instrument,
he determined that the material in HD 113866 is more processed than the
snowball-like stuff that makes up infant solar systems and comets, which are
considered cosmic "refrigerators" because they contain pristine ingredients from
the early solar system. However, it is also not as processed as the stuff found
in mature planets and the largest asteroids. This means the dust belt must be in
a transitional phase, when rocky planets are just beginning to form.
How do scientists know the material is more processed than that
of comets? >From missions like NASA's Deep Impact - in which an 820-pound
impactor spacecraft collided with comet Tempel 1 - scientists know that early
star systems contain a lot of fragile organic material. That material includes
polycyclic aromatic hydrocarbons (carbon-based molecules found on charred
barbeque grills and automobile exhaust on Earth), water ice, and carbonates
(chalk). Lisse says that HD 113766 does not contain any water ice, carbonates or
fragile organic materials.
From meteorite studies on Earth, scientists also have a good
idea of what makes up asteroids - the more processed rocky leftovers of planet
formation. These studies tell us that metals began separating from rocks in
Earth's early days, when the planet's body was completely molten. During this
time, almost all the heavy metals fell to Earth's center in a process called
"differentiation." Lisse says that, unlike planets and asteroids, the metals in
HD 113766 have not totally separated from the rocky material, suggesting that
rocky planets have not yet formed.
"The material mix in this belt is most reminiscent of the stuff
found in lava flows on Earth. I thought of Mauna Kea material when I first saw
the dust composition in this system - it contains raw rock and is abundant in
iron sulfides, which are similar to fool's gold," says Lisse, referring to a
well-known Hawaiian volcano.
"It is fantastic to think we are able to detect the process of
terrestrial planet formation. Stay tuned -- I expect lots more fireworks as the
planet in HD 113766 grows," he adds.
Lisse has written a paper on his research that will be published
in an upcoming issue of Astrophysical Journal; he will also present his findings
next week at the American Astronomical Society
Division for Planetary Sciences meeting in Orlando, Fla. Lisse's research
was funded through a Johns Hopkins Applied Physics Laboratory Stuart S. Janney
Fellowship and a Spitzer Space Telescope guest observer grant.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the
Spitzer Space Telescope mission for NASA's Science Mission Directorate,
Washington. Science operations are conducted at the Spitzer Science Center at
the California Institute of Technology, also in Pasadena. Caltech manages JPL
for NASA. The University of Maryland is responsible for overall Deep Impact
mission science, and project management is handled by JPL.
The Applied Physics Laboratory, a division of The Johns Hopkins
University, meets critical national challenges through the innovative
application of science and technology. For more information, visit
www.jhuapl.edu
About Researcher:
Dr. Carey Lisse
Email: carey.lisse@jhuapl.edu
Note to editors: an image to accompany this release is available at: http://www.jhuapl.edu/newscenter/pressreleases/2007/071003.asp
Science Contact: Dr. Carey Lisse
(240) 228-0535 or (443) 778-0535
The Applied Physics Laboratory, a division of The Johns Hopkins University,
meets critical national challenges through the innovative application of science
and technology. For more information, visit
http://www.jhuapl.edu
Media Contact: Michael Buckley
Michael.Buckley@jhuapl.edu
phone: 240-228-7536
Johns Hopkins University
About Spitzer Space
Telescope:
The Spitzer Space Telescope (formerly the Space Infrared Telescope Facility
or SIRTF) is an infrared space observatory, the fourth and final of NASA's Great
Observatories.
The time frame of the mission will be a minimum of 2.5 years, with 5 or more
optimal. In keeping with NASA tradition, the telescope was renamed after
successful demonstration of operation, on December 18, 2003. Unlike most
telescopes which are named after famous deceased astronomers by a board of
scientists, the name for SIRTF was obtained from a contest open to the general
public (to the delight of science educators).
The name chosen was that of Dr. Lyman Spitzer, Jr., the first to propose placing
telescopes in space, in the mid-1940s.
The US$ 800 million Spitzer was launched on Monday 25 August 2003 at 1:35:39
(EDT) from Cape Canaveral Air Force Station on a Delta II 7920H ELV rocket. It
follows a rather unusual orbit, heliocentric instead of geocentric, following
earth in its orbit, and drifting away from Earth at approximately 0.1
astronomical unit per year (a so-called "earth-trailing" orbit). The primary
mirror is 85 cm in diameter, f/12 (i. e. the focal length is 12 times the
diameter of the primary mirror) and made of beryllium and cooled to 5.5 K. The
satellite contains three instruments that will allow it to perform imaging and
photometry from 3 to 180 micrometers, spectroscopy from 5 to 40 micrometers, and
spectrophotometry from 5 to 100 micrometers.
Related Links:
http://www.stsci.edu/
http://www.spacetelescope.org/
http://www.spitzer.caltech.edu/
http://www.jwst.nasa.gov/
http://www.nasa.gov/spitzer/
 
| Related research: |
'Thermometer Camera' ; 12-m telescope which allow to map large areas on the sky with high sensitivity, A new milestone in the GMES Space Component Programme successfully achieved, An international team of physicists suggests burst of gamma rays possibly lacked a gravitational wave, Arecibo Observatory finds Neutron Stars can be Considerably more Massive and also difficult to form Black Holes, Astronomers have Found 10 new Planets Outside Solar System Using a System of Robotic Cameras, Chandra discovers One of the fastest moving stars, cosmic cannonball, Did the big bang spawn trillions of black holes?, Discovery of the largest example of a “small” black hole, Fe-60 in the galaxy, Fleeting blue flashes of radiation emitted by particles may help crack cosmic mystery, Haptic technology ; the sense of touch to virtual worlds, Hawaii Reveals Steamy Martian Underground, Lava may have buried signs of Mars water, MU Engineers Develop an efficient and highly sophisticated mathematical algorithm for Complex Space Missions, Nano-sized Electronic Circuit Promises Bright View of Early Universe, NASA and NOAA Regarding Concerns Over NPOESS Preparatory Project VIIRS Sensor, NASA celebrates a decade observing climate impacts on health of world's oceans, NASA Goddard Lunar Science on a Roll, NASA Mars Reconnaissance Orbiter Provides Insights About Mars Water and Climate, NASA Orbiter Finds Possible Cave Skylights on Mars, Nasa satellite shows regional variation in warming from sun during solar cycle, NASA Scientist Available for Interviews About New Jupiter Findings, NASA Spacecraft Is a 'Go' for Asteroid Belt, New Research Found that Comet Dust resembles Asteroid Materials with Samples from the Comet Wild 2 Carried by Stardust Mission, New Research have Made the Best Determination of the Power of a Supernova Explosion Using X-ray and Optical Observations
|
|
