NASA's Spitzer detects comet storm in nearby solar system

ScienceDaily (Oct. 19, 2011) — NASA's Spitzer Space Telescope has detected signs of icy bodies raining down in an alien solar system. The downpour resembles our own solar system several billion years ago during a period known as the "Late Heavy Bombardment," which may have brought water and other life-forming ingredients to Earth.

During this epoch, comets and other frosty objects that were flung from the outer solar system pummeled the inner planets. The barrage scarred our moon and produced large amounts of dust.

Now Spitzer has spotted a band of dust around a nearby bright star in the northern sky called Eta Corvi that strongly matches the contents of an obliterated giant comet. This dust is located close enough to Eta Corvi that Earth-like worlds could exist, suggesting a collision took place between a planet and one or more comets. The Eta Corvi system is approximately one billion years old, which researchers think is about the right age for such a hailstorm.

"We believe we have direct evidence for an ongoing Late Heavy Bombardment in the nearby star system Eta Corvi, occurring about the same time as in our solar system," said Carey Lisse, senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., and lead author of a paper detailing the findings. The findings will be published in the Astrophysical Journal. Lisse presented the results at the Signposts of Planets meeting at NASA's Goddard Space Flight Center in Greenbelt, Md., on Oct. 19.

Astronomers used Spitzer's infrared detectors to analyze the light coming from the dust around Eta Corvi. Certain chemical fingerprints were observed, including water ice, organics and rock, which indicate a giant comet source.

The light signature emitted by the dust around Eta Corvi also resembles the Almahata Sitta meteorite, which fell to Earth in fragments across Sudan in 2008. The similarities between the meteorite and the object obliterated in Eta Corvi imply a common birthplace in their respective solar systems.

A second, more massive ring of colder dust located at the far edge of the Eta Corvi system seems like the proper environment for a reservoir of cometary bodies. This bright ring, discovered in 2005, looms at about 150 times the distance from Eta Corvi as Earth is from the sun. Our solar system has a similar region, known as the Kuiper Belt, where icy and rocky leftovers from planet formation linger. The new Spitzer data suggest that the Almahata Sitta meteorite may have originated in our own Kuiper Belt.

The Kuiper Belt was home to a vastly greater number of these frozen bodies, collectively dubbed Kuiper Belt objects. About 4 billion years ago, some 600 million years after our solar system formed, scientists think the Kuiper Belt was disturbed by a migration of the gas-giant planets Jupiter and Saturn. This jarring shift in the solar system's gravitational balance scattered the icy bodies in the Kuiper Belt, flinging the vast majority into interstellar space and producing cold dust in the belt. Some Kuiper Belt objects, however, were set on paths that crossed the orbits of the inner planets.

The resulting bombardment of comets lasted until 3.8 billion years ago. After comets impacted the side of the moon that faces Earth, magma seeped out of the lunar crust, eventually cooling into dark "seas," or maria. When viewed against the lighter surrounding areas of the lunar surface, those seas form the distinctive "Man in the Moon" visage. Comets also struck Earth or incinerated in the atmosphere, and are thought to have deposited water and carbon on our planet. This period of impacts might have helped life form by delivering its crucial ingredients.

"We think the Eta Corvi system should be studied in detail to learn more about the rain of impacting comets and other objects that may have started life on our own planet," Lisse said.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information about Spitzer, visit http://spitzer.caltech.edu/ and http://www.nasa.gov/spitzer .

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Spitzer detects shadow of 'super-Earth' in front of nearby star

ScienceDaily (May 5, 2011) — NASA's Spitzer Space Telescope has detected the crossing of a solid planet  in front of a star located at only 42 light-years in the constellation Cancer. Thanks to this detection, astronomers know that this "super-Earth" measures 2.1 times the size of our Earth. This is the smallest exoplanet detected in the neighborhood of our Sun.

The discovery is based on data acquired by the Spitzer spacecraft last January. The data allowed astronomers to detect the "transit" of the planet, i.e. the tiny decrease of the star's brightness occurring when the planet passes in front of it.

"So far, the exquisite capabilities of Spitzer have been extensively used to study known transiting exoplanets, all of them being giant planets similar to Jupiter or Neptune. For the first time, Spitzer is used to detect the transit of a super-Earth, a solid planet not much larger than our own Earth," says Michaël Gillon from University of Liège (Belgium), the leader of the team that made this detection. "Thanks to the high-precision of Spitzer, we now know the nature of this planet, and, interestingly, it is very different from all the planets of our solar System."

The planet name is 55 Cancri e. With 8 times the mass of the Earth, for a size 2.1 larger, it is simply too big to be purely rocky, meaning that it must have a significant fraction of ice, the favored composition being a massive shell of water ice on top of a rocky nucleus. "We could call this planet a 'naked Neptune', as it is very similar to Neptune except that it has no gazeous envelope of hydrogen above its ice shell," says Brice-Olivier Demory from the Massachusets Institute of Technology (MIT), the first author of the paper describing the discovery. "But the analogy with Neptune stops here: 55 Cancri e is more than 1900 times closer to its star than Neptune to the Sun. At such a short distance, the planet is literally baked by the intense stellar radiation."

The host star itself  has a particularity that makes this planet very interesting for astronomers. It is not a dim star that can only be seen with a telescope, but a very bright star of the solar neighborhood (42 light-years), visible even for the human eye. "The brightness of the host star will make possible the first throrough characterization of a solid planet orbiting a star similar to our Sun," says Gillon. "If this planet has an atmosphere, we will be able to study it details, unlike the other solid planets found  so far around farer and dimmer stars."

Interestingly, the study of the atmosphere of 55 Cancri e has maybe already begun. Indeed, another team of astronomers indepently announced April 29, the detection of the transits of the same planet with another space telescope, MOST. This team observed at a different wavelength than Spitzer, and their measured planet radius is 1.3 times smaller. "A possible explanation for this discrepancy would be the presence of a huge molecular enveloppe outgassed by the planet, making the planet appear larger for Spitzer," says Demory. "Only new measurements will tell us."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Liège.

Journal References:

B.-O. Demory, M. Gillon, D. Deming, D. Valencia, S. Seager, B. Benneke, C. Lovis, P. Cubillos, J. Harrington, K. B. Stevenson, M. Mayor, F. Pepe, D. Queloz, D. Segransan, S. Udry. Detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer. Astronomy & Astrophysics, 2011; (submitted) [link]Joshua N. Winn, Jaymie M. Matthews, Rebekah I. Dawson, Daniel Fabrycky, Matthew J. Holman, Thomas Kallinger, Rainer Kuschnig, Dimitar Sasselov, Diana Dragomir, David B. Guenther, Anthony F.J. Moffat, Jason F. Rowe, Slavek Rucinski, Werner W. Weiss. A Super-Earth Transiting a Naked-Eye Star. Astrophysical Journal Letters, 2011; (submitted) [link]

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Spitzer detects shadow of 'super-Earth' in front of nearby star

ScienceDaily (May 5, 2011) — NASA's Spitzer Space Telescope has detected the crossing of a solid planet  in front of a star located at only 42 light-years in the constellation Cancer. Thanks to this detection, astronomers know that this "super-Earth" measures 2.1 times the size of our Earth. This is the smallest exoplanet detected in the neighborhood of our Sun.

The discovery is based on data acquired by the Spitzer spacecraft last January. The data allowed astronomers to detect the "transit" of the planet, i.e. the tiny decrease of the star's brightness occurring when the planet passes in front of it.

"So far, the exquisite capabilities of Spitzer have been extensively used to study known transiting exoplanets, all of them being giant planets similar to Jupiter or Neptune. For the first time, Spitzer is used to detect the transit of a super-Earth, a solid planet not much larger than our own Earth," says Michaël Gillon from University of Liège (Belgium), the leader of the team that made this detection. "Thanks to the high-precision of Spitzer, we now know the nature of this planet, and, interestingly, it is very different from all the planets of our solar System."

The planet name is 55 Cancri e. With 8 times the mass of the Earth, for a size 2.1 larger, it is simply too big to be purely rocky, meaning that it must have a significant fraction of ice, the favored composition being a massive shell of water ice on top of a rocky nucleus. "We could call this planet a 'naked Neptune', as it is very similar to Neptune except that it has no gazeous envelope of hydrogen above its ice shell," says Brice-Olivier Demory from the Massachusets Institute of Technology (MIT), the first author of the paper describing the discovery. "But the analogy with Neptune stops here: 55 Cancri e is more than 1900 times closer to its star than Neptune to the Sun. At such a short distance, the planet is literally baked by the intense stellar radiation."

The host star itself  has a particularity that makes this planet very interesting for astronomers. It is not a dim star that can only be seen with a telescope, but a very bright star of the solar neighborhood (42 light-years), visible even for the human eye. "The brightness of the host star will make possible the first throrough characterization of a solid planet orbiting a star similar to our Sun," says Gillon. "If this planet has an atmosphere, we will be able to study it details, unlike the other solid planets found  so far around farer and dimmer stars."

Interestingly, the study of the atmosphere of 55 Cancri e has maybe already begun. Indeed, another team of astronomers indepently announced April 29, the detection of the transits of the same planet with another space telescope, MOST. This team observed at a different wavelength than Spitzer, and their measured planet radius is 1.3 times smaller. "A possible explanation for this discrepancy would be the presence of a huge molecular enveloppe outgassed by the planet, making the planet appear larger for Spitzer," says Demory. "Only new measurements will tell us."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Liège.

Journal References:

B.-O. Demory, M. Gillon, D. Deming, D. Valencia, S. Seager, B. Benneke, C. Lovis, P. Cubillos, J. Harrington, K. B. Stevenson, M. Mayor, F. Pepe, D. Queloz, D. Segransan, S. Udry. Detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer. Astronomy & Astrophysics, 2011; (submitted) [link]Joshua N. Winn, Jaymie M. Matthews, Rebekah I. Dawson, Daniel Fabrycky, Matthew J. Holman, Thomas Kallinger, Rainer Kuschnig, Dimitar Sasselov, Diana Dragomir, David B. Guenther, Anthony F.J. Moffat, Jason F. Rowe, Slavek Rucinski, Werner W. Weiss. A Super-Earth Transiting a Naked-Eye Star. Astrophysical Journal Letters, 2011; (submitted) [link]

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Self-powered, blood-activated sensor detects pancreatitis quickly and cheaply

ScienceDaily (Apr. 25, 2011) — A new low cost test for acute pancreatitis that gets results much faster than existing tests has been developed by scientists at The University of Texas at Austin.

The sensor, which could be produced for as little as a dollar, is built with a 12-cent LED light, aluminum foil, gelatin, milk protein and a few other cheap, easily obtainable materials.

The sensor could help prevent damage from acute pancreatitis, which is a sudden inflammation of the pancreas that can lead to severe stomach pain, nausea, fever, shock and in some cases, death.

"We've turned Reynold's Wrap, JELL-O and milk into a way to look for organ failure," says Brian Zaccheo, a graduate student in the lab of Richard Crooks, professor of chemistry and biochemistry.

The sensor, which is about the size of a matchbox, relies on a simple two-step process to diagnose the disease.

In step one, a bit of blood extract is dropped onto a layer of gelatin and milk protein. If there are high levels of trypsin, an enzyme that is overabundant in the blood of patients with acute pancreatitis, the trypsin will break down the gelatin in much the same way it breaks down proteins in the stomach.

In step two, a drop of sodium hydroxide (lye) is added. If the trypsin levels were high enough to break down that first barrier, the sodium hydroxide can trickle down to the second barrier, a strip of Reynold's wrap, and go to work dissolving it.

The foil corrodes, and with both barriers now permeable, a circuit is able to form between a magnesium anode and an iron salt at the cathode. Enough current is generated to light up a red LED. If the LED lights up within an hour, acute pancreatitis is diagnosed.

"In essence, the device is a battery having a trypsin-selective switch that closes the circuit between the anode and cathode," write Zaccheo and Crooks in a paper recently published in Analytical Chemistry.

Zaccheo and Crooks, who have a provisional patent, can envision a number of potential uses for the sensor. It might help providers in the developing world who don't have the resources to do the more complex tests for pancreatitis. It could be of use in situations where batteries are in short supply, such as after a natural disaster or in remote locations. And because of the speed of the sensor, it could be an excellent first-line measure even in well-stocked hospitals.

For Zaccheo, the most appealing aspect of the project isn't so much the specific sensor. It is the idea we might be able to save time, money and even lives by adopting this kind of low-tech approach.

"I want to develop biosensors that are easy to use but give a high level of sensitivity," he says. "All you need for this, for instance, is to know how to use a dropper and a timer."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Texas at Austin.

Journal Reference:

Brian A. Zaccheo, Richard M. Crooks. Self-Powered Sensor for Naked-Eye Detection of Serum Trypsin. Analytical Chemistry, 2011; 83 (4): 1185 DOI: 10.1021/ac103115z

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Self-powered, blood-activated sensor detects pancreatitis quickly and cheaply

ScienceDaily (Apr. 25, 2011) — A new low cost test for acute pancreatitis that gets results much faster than existing tests has been developed by scientists at The University of Texas at Austin.

The sensor, which could be produced for as little as a dollar, is built with a 12-cent LED light, aluminum foil, gelatin, milk protein and a few other cheap, easily obtainable materials.

The sensor could help prevent damage from acute pancreatitis, which is a sudden inflammation of the pancreas that can lead to severe stomach pain, nausea, fever, shock and in some cases, death.

"We've turned Reynold's Wrap, JELL-O and milk into a way to look for organ failure," says Brian Zaccheo, a graduate student in the lab of Richard Crooks, professor of chemistry and biochemistry.

The sensor, which is about the size of a matchbox, relies on a simple two-step process to diagnose the disease.

In step one, a bit of blood extract is dropped onto a layer of gelatin and milk protein. If there are high levels of trypsin, an enzyme that is overabundant in the blood of patients with acute pancreatitis, the trypsin will break down the gelatin in much the same way it breaks down proteins in the stomach.

In step two, a drop of sodium hydroxide (lye) is added. If the trypsin levels were high enough to break down that first barrier, the sodium hydroxide can trickle down to the second barrier, a strip of Reynold's wrap, and go to work dissolving it.

The foil corrodes, and with both barriers now permeable, a circuit is able to form between a magnesium anode and an iron salt at the cathode. Enough current is generated to light up a red LED. If the LED lights up within an hour, acute pancreatitis is diagnosed.

"In essence, the device is a battery having a trypsin-selective switch that closes the circuit between the anode and cathode," write Zaccheo and Crooks in a paper recently published in Analytical Chemistry.

Zaccheo and Crooks, who have a provisional patent, can envision a number of potential uses for the sensor. It might help providers in the developing world who don't have the resources to do the more complex tests for pancreatitis. It could be of use in situations where batteries are in short supply, such as after a natural disaster or in remote locations. And because of the speed of the sensor, it could be an excellent first-line measure even in well-stocked hospitals.

For Zaccheo, the most appealing aspect of the project isn't so much the specific sensor. It is the idea we might be able to save time, money and even lives by adopting this kind of low-tech approach.

"I want to develop biosensors that are easy to use but give a high level of sensitivity," he says. "All you need for this, for instance, is to know how to use a dropper and a timer."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Texas at Austin.

Journal Reference:

Brian A. Zaccheo, Richard M. Crooks. Self-Powered Sensor for Naked-Eye Detection of Serum Trypsin. Analytical Chemistry, 2011; 83 (4): 1185 DOI: 10.1021/ac103115z

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here