Hubble Sees an Unexpected Population of Young-Looking Stars

The NASA/ESA Hubble Space Telescope offers an impressive view of the center of globular cluster NGC 6362. The image of this spherical collection of stars takes a deeper look at the core of the globular cluster, which contains a high concentration of stars with different colors.

Tightly bound by gravity, globular clusters are composed of old stars, which, at around 10 billion years old, are much older than the sun. These clusters are fairly common, with more than 150 currently known in our galaxy, the Milky Way, and more which have been spotted in other galaxies.

Globular clusters are among the oldest structures in the Universe that are accessible to direct observational investigation, making them living fossils from the early years of the cosmos.


Astronomers infer important properties of globular clusters by looking at the light from their constituent stars. For many years, they were regarded as ideal laboratories for testing the standard stellar evolution theory. Among other things, this theory suggests that most of the stars within a globular cluster should be of a similar age.

Recently, however, high precision measurements performed in numerous globular clusters, primarily with the Hubble Space Telescope, have led some to question this widely accepted theory. In particular, certain stars appear younger and bluer than their companions, and they have been dubbed blue stragglers. NGC 6362 contains many of these stars.

Since they are usually found in the core regions of clusters, where the concentration of stars is large, the most likely explanation for this unexpected population of objects seems to be that they could be either the result of stellar collisions or transfer of material between stars in binary systems. This influx of new material would heat up the star and make it appear younger than its neighbors.

SpaceX Transitions to Third Commercial Crew Phase

 This artist concept shows the second stage engine of a SpaceX Falcon 9
rocket igniting to send the company's Dragon capsule
into orbit as the first stage falls away.

Space Exploration Technologies (SpaceX) has completed its first three performance milestones for NASA's Commercial Crew Integrated Capability (CCiCap) initiative, which is intended to lead to the availability of commercial human spaceflight services for government and commercial customers. 

During the company's first milestone, a technical baseline review, NASA and SpaceX reviewed the Dragon spacecraft and Falcon 9 rocket for crew transportation to low-Earth orbit and discussed future plans for ground operations for crewed flights. The second milestone included a review of the company's plan to achieve the CCiCap milestones established during SpaceX's $440 million Space Act Agreement. SpaceX also presented the company's financial resources to support its co-investment in CCiCap. 

At the company's headquarters in Hawthorne, Calif., on Oct. 29, SpaceX presented techniques it will use to design, build and test its integrated system during the third milestone, called an integrated systems requirements review. The company also provided NASA with the initial plans it would use for managing ground operations, launch, ascent, in-orbit operations, re-entry and landing should they begin transporting crews.

SpaceX is one of three U.S. companies NASA is working with during CCiCap to set the stage for a crewed orbital demonstration mission around the middle of the decade. SpaceX already is executing a contract with NASA for 12 cargo resupply missions to the International Space Station.

"The Dragon spacecraft has successfully delivered cargo to the space station twice this year, and SpaceX is well under way toward upgrading Dragon to transport astronauts as well," said SpaceX President Gwynne Shotwell. 

High-Resolution Self-Portrait by Curiosity Rover Arm Camera

NASA Rover Finds Clues to Changes in Mars' Atmosphere

PASADENA, Calif. -- NASA's car-sized rover, Curiosity, has taken significant steps toward understanding how Mars may have lost much of its original atmosphere.

Learning what happened to the Martian atmosphere will help scientists assess whether the planet ever was habitable. The present atmosphere of Mars is 100 times thinner than Earth's.

A set of instruments aboard the rover has ingested and analyzed samples of the atmosphere collected near the "Rocknest" site in Gale Crater where the rover is stopped for research. Findings from the Sample Analysis at Mars (SAM) instruments suggest that loss of a fraction of the atmosphere, resulting from a physical process favoring retention of heavier isotopes of certain elements, has been a significant factor in the evolution of the planet. Isotopes are variants of the same element with different atomic weights.

This picture shows a lab demonstration of the measurement
chamber inside the Tunable Laser Spectrometer, an instrument that is part of
the Sample Analysis at Mars investigation on NASA's Curiosity rover.

Initial SAM results show an increase of five percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed. These enriched ratios of heavier isotopes to lighter ones suggest the top of the atmosphere may have been lost to interplanetary space. Losses at the top of the atmosphere would deplete lighter isotopes. Isotopes of argon also show enrichment of the heavy isotope, matching previous estimates of atmosphere composition derived from studies of Martian meteorites on Earth.

Scientists theorize that in Mars' distant past its environment may have been quite different, with persistent water and a thicker atmosphere. NASA's Mars Atmosphere and Volatile Evolution, or MAVEN, mission will investigate possible losses from the upper atmosphere when it arrives at Mars in 2014.

Scientists Monitor Comet Breakup

The Hergenrother comet is currently traversing the inner-solar system. Amateur and professional astronomers alike have been following the icy-dirt ball over the past several weeks as it has been generating a series of impressive outbursts of cometary-dust material. Now comes word that the comet's nucleus has taken the next step in its relationship with Mother Nature.

With more material to reflect the sun's rays, the comet's coma has brightened considerably.

Comet 168P-Hergenrother was imaged by the NOAO/Gemini telescope on
 Nov. 2, 2011 at about 6 a.m.

"The comet fragments are considerably fainter than the nucleus," said James Bauer, the deputy principal investigator for NASA's NEOWISE mission, from the California Institute of Technology. "This is suggestive of chunks of material being ejected from the surface."

For those interested in viewing Hergenrother, with a larger-sized telescope and a dark sky, the comet can be seen in between the constellations of Andromeda and Lacerta.

The orbit of comet 168P/Hergenrother comet is well understood. The comet, nor any of its fragments, are a threat to Earth.