Astronomers Discover Transiting Exoplanet with Longest Known Year

This artist's conception shows Kepler-421b, a Uranus-sized transiting exoplanet with the longest known year, circling its star once every 704 days. Kepler-421b orbits an orange, K-type star that is cooler and dimmer than our sun and is located about 1,000 light-years from Earth in the constellation Image Credit: Harvard-Smithsonian, Center for Astrophysics/D. A. Aguilar

Astronomers using NASA Kepler data have discovered a transiting exoplanet with the longest known year. Kepler-421b orbits its star once every 704 days. In comparison, Mars orbits our sun once every 780 days. Most of the more than 1,800 confirmed exoplanets discovered to date are much closer to their stars and have much shorter orbital periods.

Dr. David Kipping.

“Finding Kepler-421b was a stroke of luck,” says lead author David Kipping of the Harvard-Smithsonian Center for Astrophysics. “The farther a planet is from its star, the less likely it is to transit the star from Earth’s point of view. It has to line up just right.”

Kepler-421b orbits an orange, K-type star that is cooler and dimmer than our sun and is located about 1,000 light-years from Earth in the constellation Lyra.

The newly confirmed world circles the star at a distance of about 110 million miles. As a result, this Uranus-sized planet is chilled to a temperature of -135 degrees Fahrenheit (-93 degrees Celsius).

This research has been accepted for publication in The Astrophysical Journal and is available online.

Additional information can be found at: https://www.cfa.harvard.edu/~dkipping/kepler421.html.

NASA’s Ames Research Center is responsible for the Kepler mission concept, ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.

Ball Aerospace & 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 Kepler science data.

Kepler is NASA’s 10th Discovery Mission and was funded by the agency’s Science Mission Directorate.

 

Michele Johnson
Ames Research Center, Moffett Field, Calif.
650-604-6982
michele.johnson@nasa.gov

New Research Shows Promise in the Fight Against Drug-Resistant Microbes.

Scanning electron microscopy images of Escherichia coli before (top) and after (bottom) two-hour treatment with a polymer. The treated E. coli cells show distorted and corrugated surfaces compared to the intact control cells. Credit: American Chemical Society.

The rise of drug-resistant microbes is a major challenge facing medicine. The World Health Organization’s 2014 report on global surveillance of antimicrobial resistance warns of the very real possibility of the twenty-first century becoming “a post-antibiotic era—in which common infections and minor injuries can kill”. In the face of this threat, researchers worldwide are exploring approaches to find new compounds that combine selective antimicrobial efficacy with low toxicity toward mammalian cells.

Yi Yan Yang at the A*STAR Institute of Bioengineering and Nanotechnology in Singapore and co-workers have now created a range of large polycarbonate molecules that are potent antimicrobials and are tolerated well by rat red blood cells, suggesting that they could prove similarly effective in humans. Crucially, by subtly varying the composition of the polycarbonate molecules, the researchers could fine-tune the selectivity and activity of these candidate drugs.

Antimicrobial polycarbonates are long-chain polymers made by linking small monomer molecules. Each monomer contains two components: one that is hydrophobic and physically inserts into the cell membrane of bacteria and fungi; and one that carries a positively charged group that is attracted to the negative charge on the surface of microbial cells.

By carefully tinkering with the hydrophobic and hydrophilic balance between the components of these new monomers, the researchers were able to create polymers that adhere to microbial cells and disrupt their cell membranes, thereby killing the cells (see image).

The polycarbonates developed by the researchers have proven highly effective against a variety of clinically isolated multidrug-resistant bacteria and fungi. A further benefit is that the molecules are biodegradable, which means that, when used in clinical situations, they should take effect and then degrade naturally. This attribute provides a crucial advantage over other synthetic alternatives that persist and cause undesirable side effects.

Using scanning electron microscopy, the researchers showed that the molecules work by breaking open the microbial cell membrane—a mode of action they believe reduces the likelihood of microbes becoming resistant to the polycarbonates.

The ability to explore different compositions within the monomers may allow further enhancements, according to the researchers. “By carefully controlling the structure and the ratio of the two components, we can enhance dramatically the selectivity of the polymers toward a broad range of pathogenic microbes,” says Yang. The researchers will now study the in vivo efficacy of the optimal polymer using intravenous injection into mice infected with methicillin-resistant Staphylococcus aureus (MRSA) bacteria that have developed resistance to a broad class of antibiotics.

Provided by: Agency for Science, Technology and Research (A*STAR), Singapore

NASA Taking Steps to Protect Mars Orbiters From Approaching Comet.

This graphic depicts the orbit of comet C/2013 A1 Siding Spring as it swings around the sun in 2014. On Oct. 19, the comet will have a very close pass at Mars. Its nucleus will miss Mars by about 82,000 miles (132,000 kilometers). Image Credit: NASA/JPL-Caltech

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.

Image 1: Conceptual image depicting the Mars Reconnaissance Orbiter (MRO) in an elliptical low-planet orbit around Mars

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.

“Three expert teams have modeled this comet for NASA and provided forecasts for its flyby of Mars,” explained Rich Zurek, chief scientist for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “The hazard is not an impact of the comet nucleus, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles — or it might not.”

During the day’s events, the smallest distance between Siding Spring’s nucleus and Mars will be less than one-tenth the distance of any known previous Earthly comet flyby. The period of greatest risk to orbiting spacecraft will start about 90 minutes later and last about 20 minutes, when Mars will come closest to the center of the widening dust trail from the nucleus.

NASA’s Mars Reconnaissance Orbiter (MRO), seen in Image 1 above, made one orbit-adjustment maneuver on July 2 as part of the process of repositioning the spacecraft for the Oct. 19 event. An additional maneuver is planned for Aug. 27. The team operating NASA’s Mars Odyssey orbiter, seen in Image 2, is planning a similar maneuver on Aug. 5 to put that spacecraft on track to be in the right place at the right time, as well.

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, seen in Image 3, is on its way to the Red Planet and will enter orbit on Sept. 21. The MAVEN team is planning to conduct a precautionary maneuver on Oct. 9, prior to the start of the mission’s main science phase in early November.

Image 2: Conceptual drawing of Mars Odyssey over Mars.

In the days before and after the comet’s flyby, NASA will study the comet by taking advantage of how close it comes to Mars. Researchers plan to use several instruments on the Mars orbiters to study the nucleus, the coma surrounding the nucleus, and the tail of Siding Spring, as well as the possible effects on the Martian atmosphere. This particular comet has never before entered the inner solar system, so it will provide a fresh source of clues to our solar system’s earliest days.

Image 3: Artist concept of MAVEN.

MAVEN will study gases coming off the comet’s nucleus into its coma as it is warmed by the sun. MAVEN also will look for effects the comet flyby may have on the planet’s upper atmosphere and observe the comet as it travels through the solar wind.

Odyssey will study thermal and spectral properties of the comet’s coma and tail. MRO will monitor Mars’ atmosphere for possible temperature increases and cloud formation, as well as changes in electron density at high altitudes. The MRO team also plans to study gases in the comet’s coma. Along with other MRO observations, the team anticipates this event will yield detailed views of the comet’s nucleus and potentially reveal its rotation rate and surface features.

The Curiosity Rover. Image Credit: NASA/JPL-Caltech/MSSS

Mars’ atmosphere, though much thinner than Earth’s, is thick enough that NASA does not anticipate any hazard to the Opportunity and Curiosity rovers on the planet’s surface, even if dust particles from the comet hit the atmosphere and form into meteors. Rover cameras may be used to observe the comet before the flyby, and to monitor the atmosphere for meteors while the comet’s dust trail is closest to the planet.

Self-Portrait by Freshly Cleaned Opportunity Mars Rover, False Color. Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

 

 

 

Observations from Earth-based and space telescopes provided data used for modeling to make predictions about Siding Spring’s Mars flyby, which were in turn used for planning protective maneuvers. The three modeling teams were headed by researchers at the University of Maryland in College Park, the Planetary Science Institute in Tucson, Arizona, and JPL.

 

 

For more information about the Mars flyby of comet Siding Spring, visit: 

http://mars.nasa.gov/comets/sidingspring/

For more information about NASA’s Mars Exploration Program, visit:

http://www.nasa.gov/mars

 

 

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
guy.webster@jpl.nasa.gov

Delta IV to Launch AFSPC-4 July 24th at 6:59 pm EDT

Delta IV Medium 4,2. Image Credit: ULA

UPDATE:  The AFSPC4 launch on a DeltaIV has been scrubbed again because of weather and is rescheduled for July 28 (Monday). 65-min launch window opens at 6:55 pm EDT.

Click here to watch live coverage of the Delta IV launch. Coverage begins July 24 at 6:39 p.m. EDT.
•    Mobile devices: click here

Delta IV AFSPC-4 Mission Brochure

Rocket/Payload: 
 A Delta IV Medium+ (4,2) will launch the AFSPC-4 mission for the U.S Air Force.

Date/Site/Launch Time: Wednesday, July 24, from Space Launch Complex (SLC)-37 at Cape Canaveral Air Force Station, Florida. Launch is planned for 6:59 p.m. EDT.

Viewing the Launch by Webcast: The live webcast will begin at 6:39 p.m. EDT.

Mission Description: The AFSPC-4 mission will deliver two Geosynchronous Space Situational Awareness Program (GSSAP) satellites to near-geosyn¬chronous orbit and will also carry an Automated Navigation and Guidance Experiment for Local Space (ANGELS) satellite.

The twin GSSAP spacecraft will support U.S. Strategic Command space surveillance operations as a dedicated Space Surveillance Network (SSN) sensor. The GSSAP will also support Joint Functional Component Command for Space (JFCC SPACE) tasking to collect space situ¬ational awareness data, allowing for more accurate tracking and characterization of man-made orbiting objects.

The ANGELS satellite is managed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate. As part of AFRL’s research in advanced Space Situational Awareness (SSA), ANGELS examines techniques for providing a clearer picture of the environment surrounding our nation’s vital space assets.

Launch Notes: AFSPC-4 will be the 33rd ULA mission for the U.S. Air Force. It will be the eighth of 15 planned missions ULA is slated to launch in 2014, and ULA’s 85th since the company formed in 2006.

Current Weather Radar at Kennedy Space Center:  http://archive.firstcoastnews.com/weather/radar/kennedyspace.aspx

Launch Updates: To keep up to speed with updates to the launch countdown, dial the ULA launch hotline at 1-877-852-4321 or join the conversation at www.facebook.com/ulalaunch and twitter.com/ulalaunch.

Go Delta! Go AFSPC-4!

Chandra X-ray Observatory Celebrates Its 15th Anniversary

Image credit: NASA/CXC/SAO

In commemoration of the 15th anniversary of NASA’s Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate Chandra’s unique ability to explore high-energy processes in the cosmos.

The images of the Tycho and G292.0+1.8 supernova remnants show how Chandra can trace the expanding debris of an exploded star and the associated shock waves that rumble through interstellar space at speeds of millions of miles per hour. The images of the Crab Nebula and 3C 58 show how extremely dense, rapidly rotating neutron stars produced when a massive star explodes can create clouds of high-energy particles light years across that glow brightly in X-rays.

Tycho: More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of the exploded star produced a shock wave moving outward into the surrounding interstellar gas, and another, reverse shock wave moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion in exquisite detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that these shock waves may be responsible for some of the cosmic rays – ultra-energetic particles – that pervade the Galaxy and constantly bombard the Earth.

G292.0+1.8: At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded.

The Crab Nebula: In 1054 AD, Chinese astronomers and others around the world noticed a new bright object in the sky. This “new star” was, in fact, the supernova explosion that created what is now called the Crab Nebula. At the center of the Crab Nebula is an extremely dense, rapidly rotating neutron star left behind by the explosion. The neutron star, also known as a pulsar, is spewing out a blizzard of high-energy particles, producing the expanding X-ray nebula seen by Chandra. In this new image, lower-energy X-rays from Chandra are red, medium energy X-rays are green, and the highest-energy X-rays are blue.

3C58: 3C58 is the remnant of a supernova observed in the year 1181 AD by Chinese and Japanese astronomers. This new Chandra image shows the center of 3C58, which contains a rapidly spinning neutron star surrounded by a thick ring, or torus, of X-ray emission. The pulsar also has produced jets of X-rays blasting away from it to both the left and right, and extending trillions of miles. These jets are responsible for creating the elaborate web of loops and swirls revealed in the X-ray data. These features, similar to those found in the Crab, are evidence that 3C58 and others like it are capable of generating both swarms of high-energy particles and powerful magnetic fields. In this image, low, medium, and high-energy X-rays detected by Chandra are red, green, and blue respectively.