Planet race heats up: 1 month, 32 discoveries
Planet race heats up: 1 month, 32 discoveries
June 6, 2007
(PLANETQUEST) -- The race to find planets beyond our solar system heated up more than ever during the month of May, when astronomers announced 32 previously unknown planets orbiting nearby stars. The new findings increase the number of known "exoplanets" to 242.
Artist's rendering of the planet orbiting the star Gliese 436 (Lynette Cooke/California & Carnegie Planet Search)
At least four of the stars astronomers observed have multiple-planet solar systems, like our own. Three other stars are thought to contain the remains of failed stars, called "brown dwarfs," in addition to a planet.
One of the more exotic of the new discoveries is the planet HAT-P-2b, discovered by an international team using the Hungarian-made Automated Telescope (HAT). The planet is over eight times more massive than Jupiter despite being only slightly bigger around. It whips around its host star in just over five-and-a-half days. Another group of astronomers discovered a planet with an even shorter year: TrES-3, a planet a bit bigger than Jupiter and about twice as massive, takes about 31 hours to orbit its binary star host, one of the quickest orbits ever observed. The planet was discovered using a network of telescopes called the Trans-atlantic Exoplanet Survey (TrES).
Other planets found include XO-2 b, a planet the size of Jupiter and about half as massive, and CoRoT-Exo-1 b, another "hot Jupiter" with an orbital period of one-and-a-half Earth days. CoRoT-Exo-1 b is the first exoplanet discovered by the French planet-finding CoRoT satellite.
By far the biggest haul of new planets came from a joint effort between the California and Carnegie Planet Search and the Anglo-Australian Planet Search teams. Together, they discovered 28 new planets and four new multiple-planet solar systems in the month of May, announcing their findings at the semi-annual meeting of the American Astronomical Society in Honolulu.
Three of the new planets were found orbiting very large stars nearly twice the size of our sun. Typically, it's very difficult for astronomers to observe planets of massive stars because the stars spin very quickly and have pulsating atmospheres that can obscure or mimic planetary signals. In order to bypass this problem, the two teams have concentrated on retired "A" type stars - ones that have nearly completed their life cycle and stabilized temporarily. They have found that these larger stars tend to have larger planets - likely because these solar systems initially formed out of more raw material.
The team also found seven so-called "brown dwarfs," corpses of stars that were never big enough to maintain fusion, as well as two other objects that could either be massive planets or small brown dwarfs.
In addition to updating the roster of newly discovered planets, the California and Carnegie and Anglo-Australian teams made further observations of a planet orbiting the star Gilese 436. The planet, which is similar in size and density to Neptune, is thought to have a rocky core surrounded by water that has been compressed by temperature and pressure into a solid form. Its atmosphere may contain hydrogen and helium, which would give it a blue color as it reflects light from its host star, a red dwarf only 30 light-years from Earth.
With an orbit of just over two-and-a-half days, this "hot Neptune" lies extremely close to Gilese 436. It also has an unusually oblong orbital path that suggests the presence of another planet nearby, according to a press release by the astronomers.
This breakneck pace of discovery may be a sign of things to come, as astronomers' methods for spotting exoplanets become increasingly accurate. "We're just getting to the point where, if we were observing our own solar system from afar, we would be seeing Jupiter," Jason T. Wright, a member of the California and Carnegie Planet Search team, said in a statement.
Written by Joshua Rodriguez/PlanetQuest
source: Planet Quest
Oliver
Date: Jun 7, 2007 3:04 AM
Planet Pride
Date: Jun 7, 2007 4:05 PM
HiRISE Releases 1,200 Images, Launches Viewer on Newly Designed Website
By Lori Stiles
June 04, 2007
Spring Colors on the Southern Polar Cap on Mars - Truly other-worldly terrain, with exotic landforms having no earthly analogs. (Credit: NASA/JPL/University of Arizona)
Anyone connected by Internet can now see planet Mars better than at any time in history, through the eye of HiRISE, the most powerful camera ever to orbit another planet.
A University of Arizona-based team that runs the High Resolution Imaging Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter has just released more than 1,200 Mars images to the Planetary Data System, the U.S. space agency's mission data archive.
Not only has the team released 1.7 Terabytes of HiRISE data -- the largest single dataset ever delivered to NASA's space mission data library -- but also a user-friendly way for the public to easily see HiRISE images.
Thanks to tools available on HiRISE's new Webpage at http://hirise.lpl.arizona.edu, any Internet user can quickly pull up and explore the same remarkable images that both thrill and confound scientists.
"These images must contain hundreds of important discoveries about Mars," HiRISE Principal Investigator Alfred McEwen of UA's Lunar and Planetary Laboratory said. "We just need time to realize what they are."
The HiRISE camera takes images of 3.5-mile-wide (6 km) swaths as the orbiter flies at about 7,800 mph between 155 and 196 miles (250 to 316 km) above Mars' surface. For at least the next 18 months, HiRISE will collect thousands of color, black-and-white and stereo images of the Martian surface, resolving features as small as 40 inches across, covering about one percent of the planet.
The team based at UA's HiRISE Operations Center (HiROC) began releasing selected images on the Internet when science operations began in November 2006. Team members began reprocessing all the images taken up to March 25, 2007, using improved calibration, or image correction techniques, in April.
HiRISE BECOMES PDS 'DATA NODE'
With the first 1,200 images, HiRISE becomes a Planetary Data System (PDS) "data node."
The Planetary Data System (PDS) is used by scientists, students, textbook writers and a growing number of others who follow the latest planetary discoveries. NASA started the archive two decades ago when planetary scientists requested a system to keep the expanding volume of data collected from NASA missions in a form accessible at any time in the future, said NASA's R. Stephen Saunders, the PDS program scientist. The PDS is online at http://pds.jpl.nasa.gov.
"As computers evolve and change, we expect to always be able to access the data, a national treasure," Saunders said.
"A PDS data node is designed to provide access to a particular data set during an active mission, when the data are of greatest interest," Saunders said. Also, "NASA wants to draw on the team's expertise to make sure the data are validated, archived and useful for meeting the objectives of the MRO mission," he said. "NASA has made a large investment in software and hardware at Mars and at UA, and this is a way to capitalize further on that investment."
IAS VIEWER FOR QUICK CLOSE-UPS
The newly designed HiRISE Web site at http://hirise.lpl.arizona.edu gives general users, as well as scientists, a tool to quickly home in on any location within a single huge HiRISE image, which often will be a gigabyte image measuring 20,000 pixels by 50,000 pixels. The tool, which was developed by ITT-Visual Information Solutions in Boulder, Co., is called the IAS Viewer. Users can download it for free directly from the HiRISE Website.
Richard Cooke, president and CEO of ITT Visual Information Systems said, "ITT is committed to supporting the space science community with technology and services that advance the pursuit of discovery. Integrating our IAS technologies with the HiRISE project is very exciting for us, as it helps bring space science applications to a wider community of users, including the general public."
The advantage to IAS-Viewer technology is that it transmits only the amount of data needed to render that portion of the image displayed on the computer screen. That is, each time a user zooms in on a image, he or she doesn't download a completely new set of pixels. Instead, the user is downloading only the higher resolution parts of the image data, which are added to the image data already downloaded by the viewer. The IAS Viewer ultimately renders the selected part of the image in high resolution by adding more and more pixels.
The tool, which also has defense, intelligence and disaster management applications, delivers high quality images regardless of slow or limited network connections.
"I've run this at home, with my little cable modem," said HiROC Manager Eric Eliason. "The tool allows you to zoom in on small pieces of the image quickly, without having to download all of the information in the entire image, which would take hours. IAS Viewer will make our images much more accessible not only to our science team, but to the world."
NEW HiRISE WEBSITE FEATURES STUNNING IMAGES
HiRISE communications team member Yisrael Espinoza said he designed the new HiRISE Website to be image-driven. Visitors can take a quick look at an image, or see a larger browse version, or the full-resolution version according to how interested they are in a particular picture. The full-resolution version will launch the IAS Viewer once users have downloaded the free software onto their computers.
Tantalizing, recent results HiRISE include:
An image of a crater from an impact blast that triggered 100,000 dust avalanches.
New details on the fine-layered sedimentary rocks on plains next to Juventae Chasma, which features intriguing repeating layers.
Buried sedimentary rocks exposed in ancient terrain in the southern highlands.
A "black hole," a possible cavern on Mars. HiRISE saw no detail in the shadow, which is consistent with a deep hole and overhanging walls.
South polar 'geysers' that possibly result from the explosive release of carbon dioxide gas, trapped under pressure beneath translucent carbon dioxide ice.
"Spiders" on Mars, channels near the South Pole that apparently converge and flow uphill.
HiRISE is called "The People's Camera" because the HiRISE team provides processed images to the world to stimulate learning, discussion and investigation. HiRISE researchers encourage the scientific community and the public to help target and analyze images.
Information about the Mars Reconnaissance Orbiter is online at http://www.nasa.gov/mro. The mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona. Ball Aerospace and Technologies Corp., Boulder, Colo., built the HiRISE instrument.
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