First Rocky Planet - Kepler-10b

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

The discovery of this so-called exoplanet is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010.

"All of Kepler's best capabilities have converged to yield the first solid evidence of a rocky planet orbiting a star other than our sun," said Natalie Batalha, Kepler's deputy science team lead at NASA's Ames Research Center in Moffett Field, Calif., and primary author of a paper on the discovery accepted by the Astrophysical Journal. "The Kepler team made a commitment in 2010 about finding the telltale signatures of small planets in the data, and it's beginning to pay off."

Kepler's ultra-precise photometer measures the tiny decrease in a star's brightness that occurs when a planet crosses in front of it. The size of the planet can be derived from these periodic dips in brightness. The distance between the planet and the star is calculated by measuring the time between successive dips as the planet orbits the star.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone, the region in a planetary system where liquid water can exist on the planet's surface. However, since it orbits once every 0.84 days, Kepler-10b is more than 20 times closer to its star than Mercury is to our sun and not in the habitable zone.

Kepler-10 was the first star identified that could potentially harbor a small transiting planet, placing it at the top of the list for ground-based observations with the W.M. Keck Observatory 10-meter telescope in Hawaii.

Scientists waiting for a signal to confirm Kepler-10b as a planet were not disappointed. Keck was able to measure tiny changes in the star's spectrum, called Doppler shifts, caused by the telltale tug exerted by the orbiting planet on the star.

"The discovery of Kepler-10b, a bona fide rocky world, is a significant milestone in the search for planets similar to our own," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Although this planet is not in the habitable zone, the exciting find showcases the kinds of discoveries made possible by the mission and the promise of many more to come," he said.

"Our knowledge of the planet is only as good as the knowledge of the star it orbits," said Batalha. Because Kepler-10 is one of the brighter stars being targeted by Kepler, scientists were able to detect high frequency variations in the star's brightness generated by stellar oscillations, or starquakes. "This is the analysis that really allowed us to pin down Kepler-10b's properties.," she added.

"We have a clear signal in the data arising from light waves that travel within the interior of the star," said Hans Keldsen, an astronomer at the Kepler Asteroseismic Science Consortium at Aarhus University in Denmark. Kepler Asteroseismic Science Consortium scientists use the information to better understand the star, just as earthquakes are used to learn about Earth's interior structure. "As a result of this analysis, Kepler-10 is one of the most well characterized planet-hosting stars in the universe next to our sun," Kjeldsen said.

That's good news for the team studying Kepler-10b. Accurate stellar properties yield accurate planet properties. In the case of Kepler-10b, the picture that emerges is of a rocky planet with a mass 4.6 times that of Earth and with an average density of 8.8 grams per cubic centimeter -- similar to that of an iron dumbbell.

"This planet is unequivocally rocky, with a surface you could stand on," commented team member Dimitar Sasselov, of the Harvard-Smithsonian Center for Astrophysics in Cambridge and a Kepler co-investigator.

"All of Kepler’s best capabilities have converged for this discovery," Batalha said, "yielding the first solid evidence of a rocky planet orbiting a star other than our sun."

Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data.

Chat with NASA Experts

A new planet discovery will be announced Monday Jan. 10 during the 'Exoplanets & Their Host Stars' presentation at the American Astronomical Society (AAS) conference in Seattle, Washington.

Kepler is NASA's first mission to look specifically for Earth-size planets in the habitable zones (areas where liquid water could exist) around stars like our sun. Kepler will spend 3-1/2 years surveying more than 100,000 stars in the Cygnus-Lyra region of our Milky Way galaxy. More than 300 exoplanets have been discovered previously, most of which are low-density gas giants such as Jupiter or Saturn in our own solar system.

Natalie Batalha of the NASA Kepler Mission Team will be online answering your questions about this new planet finding on Monday, Jan. 10 from 3:30 p.m. to 4:30 p.m. EST / 12:30 p.m. to 1:30 p.m. PST. Natalie will be chatting with you live from the conference in Seattle.

Joining the chat is easy. Simply visit this page on Monday from 3:30 p.m. to 4:30 p.m. EST / 12:30 p.m. to 1:30 p.m. PST. The chat window will open at the bottom of this page starting 15 minutes before the chat. You can log in and be ready to ask questions at 3:30 p.m.

About Dr. Natalie Batalha

Natalie Batalha is a professor of physics and astronomy at San Jose State University in the heart of Silicon Valley, California and deputy science team lead for NASA’s Kepler Mission. She holds a bachelor's in physics from the University of California (UC), Berkeley and a doctorate in astrophysics from UC Santa Cruz. Batalha started her career as a stellar spectroscopist studying young, sun-like stars. After a post-doctoral fellowship in Rio de Janeiro, Brazil, Batalha returned to California. Inspired by the growing number of exoplanet discoveries she joined the team led by William Borucki at NASA's Ames Research Center, Moffett Field, Calif., working on transit photometry -- an emerging technology for finding exoplanets. As a member of the Kepler team, Batalha is responsible for the selection of the more than 150,000 stars the spacecraft monitors and works closely with team members at Ames to identify viable planet candidates from Kepler photometry.

Giant Plumes of Gas on the Sun's Surface Help Explain Coronal Heating Mystery

Among the many constantly moving, appearing, disappearing and generally explosive events in the sun's atmosphere, there exist giant plumes of gas -- as wide as a state and as long as Earth -- that zoom up from the sun's surface at 150,000 miles per hour. Known as spicules, these are one of several phenomena known to transfer energy and heat throughout the sun's magnetic atmosphere, or corona.

Thanks to NASA's Solar Dynamics Observatory (SDO) and the Japanese satellite Hinode, these spicules have recently been imaged and measured better than ever before, showing them to contain hotter gas than previously observed. Thus, they may perhaps play a key role in helping to heat the sun's corona to a staggering million degrees or more. (A number made more surprising since the sun's surface itself is only about 10,000 degrees Fahrenheit.)

Just what makes the corona so hot is a poorly understood aspect of the sun's complicated space weather system. That system can reach Earth, causing auroral lights and, if strong enough, disrupting Earth's communications and power systems. Understanding such phenomena, therefore, is an important step towards better protecting our satellites and power grids.

"The traditional view is that all heating happens higher up in the corona," says solar physicist Dean Pesnell, SDO's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "The suggestion in this paper is that cool gas is ejected from the sun's surface in spicules and gets heated on its way to the corona. This doesn't mean the old view has been completely overturned, but this is a strong suggestion that part of the spicule material gets heated to very high temperatures and provides some coronal heating."

Spicules were first named in the 1940s, but were hard to study in detail until recently, says Bart De Pontieu of Lockheed Martin's Solar and Astrophysics Laboratory, Palo Alto, Calif. whose work on this subject appears in the January 7, 2011 issue of Science magazine.

In visible light, spicules can be seen to send large masses of so-called plasma – the electromagnetic gas that surrounds the sun -- up through the lower solar atmosphere or photosphere. The amount of material sent up is stunning, some 100 times as much as streams away from the sun in the solar wind towards the edges of the solar system. But nobody knew if they contained hot gas.

"Heating of spicules to the necessary hot temperatures has never been observed, so their role in coronal heating had been dismissed as unlikely," says De Pontieu.

Now, De Pontieu's team -- which included researchers at Lockheed Martin, the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) in Colorado and the University of Oslo, Norway -- was able to combine images from SDO and Hinode to produce a more complete picture of the gas inside these gigantic fountains.

Tracking the movement and temperature of spicules relies on successfully identifying the same phenomenon in all the images. One complication comes from the fact that different instruments "see" gas at different temperatures. Pictures from Hinode in the visible light range, for example, show only cool gas, while pictures that record UV light show gas that is up to several million degrees.

To show that the previously known cool gas in a spicule lies side by side to some very hot gas requires showing that the hot and cold gas in separate images are located in the same space. Each spacecraft offered specific advantages to help confirm that one was seeing the same event in multiple images.

First, Hinode: In 2009, scientists used observations from Hinode and telescopes on Earth to, for the first time, identify a spicule when looking at it head-on. (Imagine how tough it is, looking from over 90 million miles away, to determine that you're looking at a fountain when you only have a top-down view instead of a side view.) The top-down view of a spicule ensures an image with less extraneous solar material between the camera and the fountain, thus increasing confidence that any observations of hotter gas are indeed part of the spicule itself.

The second aid to tracking a single spicule is SDO's ability to capture an image of the sun every 12 seconds. "You can track things from one image to the next and know you're looking at the same thing in a different spot," says Pesnell. "If you had an image only every 12 minutes, then you couldn't be sure that what you're looking at is the same event, since you didn't watch its whole history."

Bringing these tools together, scientists could compare simultaneous images in SDO and Hinode to create a much more complete image of spicules. They found that much of the gas is heated to a hundred thousand degrees, while a small fraction of the gas is heated to millions of degrees. Time-lapsed images show that this hot material spews high up into the corona, with much of it falling back down towards the surface of the sun. However, the small fraction of the gas that is heated to millions of degrees does not immediately return to the surface."Given the large number of spicules on the Sun, and the amount of material in the spicules, if even some of that super hot plasma stays aloft it would make a fair contribution to coronal heating," says Scott McIntosh from NCAR, who is part of the research team.

Of course, De Pontieu cautions that this does not yet solve the coronal heating mystery. The main result, he says, is that they're challenging theorists to incorporate the possibility that some coronal heating occurs at lower heights in the solar atmosphere. His next step is to help figure out how much of a role spicules play by studying how spicules form, how they move so quickly, how they get heated to such high temperatures in a short time, and how much mass stays up in the corona.

Astrophysicist Jonathan Cirtain, who is the U.S. project scientist for Hinode at NASA's Marshall Space Flight Center, Huntsville, Ala. points out that incorporating such new information helps address an important question that reaches far beyond the sun. "This breakthrough in our understanding of the mechanisms which transfer energy from the solar photosphere to the corona addresses one of the most compelling questions in stellar astrophysics: How is the atmosphere of a star heated?" he says. "This is a fantastic discovery, and demonstrates the muscle of the NASA Heliophysics System Observatory, comprised of numerous instruments on multiple observatories."

Hinode is the second mission in NASA's Solar Terrestrial Probes program, the goal of which is to improve understanding of fundamental solar and space physics processes. The mission is led by the Japan Aerospace Exploration Agency (JAXA) and the National Astronomical Observatory of Japan (NAOJ). The collaborative mission includes the U.S., the United Kingdom, Norway and Europe. NASA Marshall manages Hinode U.S. science operations and oversaw development of the scientific instrumentation provided for the mission by NASA, academia and industry. The Lockheed Martin Advanced Technology Center is the lead U.S. investigator for the Solar Optical Telescope on Hinode.

SDO is the first mission in a NASA science program called Living With a Star, the goal of which is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society. NASA Goddard built, operates, and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington.

Andromeda spiral galaxy is So Hot and Cold

This mosaic of the Andromeda spiral galaxy highlights explosive stars in its interior, and cooler, dusty stars forming in its many rings. The image is a combination of observations from the Herschel Space Observatory taken in infrared light (seen in orange hues), and the XMM-Newton telescope captured in X-rays (seen in blues). NASA plays a role in both of these European Space Agency-led missions.

Herschel provides a detailed look at the cool clouds of star birth that line the galaxy's five concentric rings. Massive young stars are heating blankets of dust that surround them, causing them to glow in the longer-wavelength infrared light, known as far-infrared, that Herschel sees.

In contrast, XMM-Newton is capturing what happens at the end of the lives of massive stars. It shows the high-energy X-rays that come from, among other objects, supernova explosions and massive dead stars rotating around companions. These X-ray sources are clustered in the center of the galaxy, where the most massive stars tend to form.

Andromeda is our Milky Way galaxy's nearest large neighbor. It is located about 2.5 million light-years away and holds up to an estimated trillion stars. Our Milky Way is thought to contain about 200 billion to 400 billion stars.

Read more at: http://www.esa.int/SPECIALS/Herschel/SEMY1K0SDIG_0.html .

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

Cassini Celebrates Ten Years Since Jupiter Encounter

Ten years ago, on Dec. 30, 2000, NASA's Cassini spacecraft made its closest approach to Jupiter on its way to orbiting Saturn. The main purpose was to use the gravity of the largest planet in our solar system to slingshot Cassini towards Saturn, its ultimate destination. But the encounter with Jupiter, Saturn's gas-giant big brother, also gave the Cassini project a perfect lab for testing its instruments and evaluating its operations plans for its tour of the ringed planet, which began in 2004.

"The Jupiter flyby allowed the Cassini spacecraft to stretch its wings, rehearsing for its prime time show, orbiting Saturn," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Ten years later, findings from the Jupiter flyby still continue to shape our understanding of similar processes in the Saturn system."

Cassini spent about six months - from October 2000 to March 2001 - exploring the Jupiter system. The closest approach brought Cassini to within about 9.7 million kilometers (6 million miles) of Jupiter's cloud tops at 2:05 a.m. Pacific Time, or 10:05 a.m. UTC, on Dec. 30, 2000.

Cassini captured some 26,000 images of Jupiter and its moons over six months of continual viewing, creating the most detailed global portrait of Jupiter yet.

While Cassini's images of Jupiter did not have higher resolution than the best from NASA's Voyager mission during its two 1979 flybys, Cassini's cameras had a wider color spectrum than those aboard Voyager, capturing wavelengths of radiation that could probe different heights in Jupiter's atmosphere. The images enabled scientists to watch convective lightning storms evolve over time and helped them understand the heights and composition of these storms and the many clouds, hazes and other types of storms that blanket Jupiter.

The Cassini images also revealed a never-before-seen large, dark oval around 60 degrees north latitude that rivaled Jupiter's Great Red Spot in size. Like the Great Red Spot, the large oval was a giant storm on Jupiter. But, unlike the Great Red Spot, which has been stable for hundreds of years, the large oval showed itself to be quite transient, growing, moving sideways, developing a bright inner core, rotating and thinning over six months. The oval was at high altitude and high latitude, so scientists think the oval may have been associated with Jupiter's powerful auroras.

The imaging team was also able to amass 70-day movies of storms forming, merging and moving near Jupiter's north pole. They showed how larger storms gained energy from swallowing smaller storms, the way big fish eat small fish. The movies also showed how the ordered flow of the eastward and westward jet streams in low latitudes gives way to a more disordered flow at high latitudes.

Meanwhile, Cassini's composite infrared spectrometer was able to do the first thorough mapping of Jupiter's temperature and atmospheric composition. The temperature maps enabled winds to be determined above the cloud tops, so scientists no longer had to rely on tracking features to measure winds. The spectrometer data showed the unexpected presence of an intense equatorial eastward jet (roughly 140 meters per second, or 310 mph) high in the stratosphere, about 100 kilometers (60 miles) above the visible clouds. Data from this instrument also led to the highest-resolution map so far of acetylene on Jupiter and the first detection of organic methyl radical and diacetylene in the auroral hot spots near Jupiter's north and south poles. These molecules are important to understanding the chemical interactions between sunlight and molecules in Jupiter's stratosphere.

As Cassini approached Jupiter, its radio and plasma wave instrument also recorded naturally occurring chirps created by electrons coming from a cosmic sonic boom. The boom occurs when supersonic solar wind - charged particles that fly off the sun - is slowed and deflected around the magnetic bubble surrounding Jupiter.

Because Cassini arrived at Jupiter while NASA's Galileo spacecraft was still orbiting the planet, scientists were also able to take advantage of near-simultaneous measurements from two different spacecraft. This coincidence enabled scientists to make giant strides in understanding the interaction of the solar wind with Jupiter. Cassini and Galileo provided the first two-point measurement of the boundary of Jupiter's magnetic bubble and showed that it was in the act of contracting as a region of higher solar wind pressure blew on it.

"The Jupiter flyby benefited us in two ways, one being the unique science data we collected and the other the knowledge we gained about how to effectively operate this complex machine," said Bob Mitchell, Cassini program manager based at JPL. "Today, 10 years later, our operations are still heavily influenced by that experience and it is serving us very well."

In celebrating the anniversary of Cassini's visit 10 years ago, scientists are also excited about the upcoming and proposed missions to the Jupiter system, including NASA's Juno spacecraft, to be launched next August, and the Europa Jupiter System Mission, which has been given a priority by NASA.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, Calif., manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md., where the instrument was built. The radio and plasma wave science team is based at the University of Iowa, Iowa City, where the instrument was built.