Tag Archives: Jpl

NASA Space Place – Comet Campaign: Amateurs Wanted

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in January, 2017.

By Marcus Woo

2013february2_spaceplaceIn a cosmic coincidence, three comets will soon be approaching Earth—and astronomers want you to help study them. This global campaign, which will begin at the end of January when the first comet is bright enough, will enlist amateur astronomers to help researchers continuously monitor how the comets change over time and, ultimately, learn what these ancient ice chunks reveal about the origins of the solar system.

Over the last few years, spacecraft like NASA’s Deep Impact/EPOXI or ESA’s Rosetta (of which NASA played a part) discovered that comets are more dynamic than anyone realized. The missions found that dust and gas burst from a comet’s nucleus every few days or weeks—fleeting phenomena that would have gone unnoticed if it weren’t for the constant and nearby observations. But space missions are expensive, so for three upcoming cometary visits, researchers are instead recruiting the combined efforts of telescopes from around the world.

“This is a way that we hope can get the same sorts of observations: by harnessing the power of the masses from various amateurs,” says Matthew Knight, an astronomer at the University of Maryland.

By observing the gas and dust in the coma (the comet’s atmosphere of gas and dust), and tracking outbursts, amateurs will help professional researchers measure the properties of the comet’s nucleus, such as its composition, rotation speed, and how well it holds together.

The observations may also help NASA scout out future destinations. The three targets are so-called Jupiter family comets, with relatively short periods just over five years—and orbits that are accessible to spacecraft. “The better understood a comet is,” Knight says, “the better NASA can plan for a mission and figure out what the environment is going to be like, and what specifications the spacecraft will need to ensure that it will be successful.”

The first comet to arrive is 41P/Tuttle–Giacobini–Kresák, whose prime window runs from the end of January to the end of July. Comet 45P/Honda–Mrkos–Pajdušáková will be most visible between mid-February and mid-March. The third target, comet 46P/Wirtanen won’t arrive until 2018.

Still, the opportunity to observe three relatively bright comets within roughly 18 months is rare. “We’re talking 20 or more years since we’ve had anything remotely resembling this,” Knight says. “Telescope technology and our knowledge of comets are just totally different now than the last time any of these were good for observing.”

For more information about how to participate in the campaign, visit www.psi.edu/41P45P46P.

Want to teach kids about the anatomy of a comet? Go to the NASA Space Place and use Comet on a Stick activity! spaceplace.nasa.gov/comet-stick/

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Caption: An orbit diagram of comet 41P/Tuttle-Giacobini-Kresak on February 8, 2017—a day that falls during the comet’s prime visibility window. The planets orbits are white curves and the comet’s orbit is a blue curve. The brighter lines indicate the portion of the orbit that is above the ecliptic plane defined by Earth’s orbital plane and the darker portions are below the ecliptic plane. This image was created with the Orbit Viewer applet, provided by the Osamu Ajiki (AstroArts) and modified by Ron Baalke (Solar System Dynamics group, JPL). ssd.jpl.nasa.gov/sbdb.cgi?orb=1;sstr=41P

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

NASA News Digest: Space Science For 4 February – 19 February 2016

Greetings fellow astrophiles,

The NASA News Service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these announcements from NASA can subscribe to their service by sending an email to: hqnews-request@newsletters.nasa.gov?subject=subscribe

NASA’s James Webb Space Telescope Primary Mirror Fully Assembled

RELEASE 16-013 (Click here for the full article) – 4 February 2016

2016feb19_16-013bThe 18th and final primary mirror segment is installed on what will be the biggest and most powerful space telescope ever launched. The final mirror installation Wednesday at NASA’s Goddard Space Flight Center in Greenbelt, Maryland marks an important milestone in the assembly of the agency’s James Webb Space Telescope.

“Scientists and engineers have been working tirelessly to install these incredible, nearly perfect mirrors that will focus light from previously hidden realms of planetary atmospheres, star forming regions and the very beginnings of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “With the mirrors finally complete, we are one step closer to the audacious observations that will unravel the mysteries of the Universe.”

Using a robotic arm reminiscent of a claw machine, the team meticulously installed all of Webb’s primary mirror segments onto the telescope structure. Each of the hexagonal-shaped mirror segments measures just over 4.2 feet (1.3 meters) across — about the size of a coffee table — and weighs approximately 88 pounds (40 kilograms). Once in space and fully deployed, the 18 primary mirror segments will work together as one large 21.3-foot diameter (6.5-meter) mirror.

To watch the Webb telescope being built at Goddard, visit the “Webb-cam” page at: www.jwst.nasa.gov/webcam.html

NASA Administrator Remembers Apollo-Era Astronaut Edgar Mitchell

RELEASE 16-014 (Click here for the full article) – 5 February 2016

2016feb19_edgar_mitchell_portraitThe following is a statement from NASA Administrator Charles Bolden on the passing of NASA astronaut Edgar Mitchell:

“On behalf of the entire NASA family, I would like to express my condolences to the family and friends of NASA astronaut Edgar Mitchell. As a member of the Apollo 14 crew, Edgar is one of only 12 men to walk on the moon and he helped to change how we view our place in the universe.

“Edgar spoke poetically about seeing our home planet from the moon saying: ‘Suddenly, from behind the rim of the moon, in long, slow-motion moments of immense majesty, there emerges a sparkling blue and white jewel, a light, delicate sky-blue sphere laced with slowly swirling veils of white, rising gradually like a small pearl in a thick sea of black mystery. It takes more than a moment to fully realize this is Earth … home.’

“He believed in exploration, having been drawn to NASA by President Kennedy’s call to send humans to the moon. He is one of the pioneers in space exploration on whose shoulders we now stand.”

For more information about Mitchell’s NASA career, and his agency biography, visit:


NASA, University Study Shows Rising Seas Slowed by Increasing Water on Land

RELEASE 16-015 (Click here for the full article) – 11 February 2016

2016feb19_16-015New measurements from a NASA satellite have allowed researchers to identify and quantify, for the first time, how climate-driven increases of liquid water storage on land have affected the rate of sea level rise.

A new study by scientists at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and the University of California, Irvine, shows that while ice sheets and glaciers continue to melt, changes in weather and climate over the past decade have caused Earth’s continents to soak up and store an extra 3.2 trillion tons of water in soils, lakes and underground aquifers, temporarily slowing the rate of sea level rise by about 20 percent.

The water gains over land were spread globally, but taken together they equal the volume of Lake Huron, the world’s seventh largest lake. The study is published in the Feb. 12 issue of the journal Science.

For more on NASA’s sea level rise research: sealevel.nasa.gov

More information on the GRACE mission can be found at: grace.jpl.nasa.gov/mission/grace/

For more on how NASA studies Earth: science.nasa.gov/earth-science/

Record Number of Americans Apply to #BeAnAstronaut at NASA

RELEASE 16-018 (Click here for the full article) – 19 February 2016

2016feb19_16-018_0More than 18,300 people applied to join NASA’s 2017 astronaut class, almost three times the number of applications received in 2012 for the most recent astronaut class, and far surpassing the previous record of 8,000 in 1978.

“It’s not at all surprising to me that so many Americans from diverse backgrounds want to personally contribute to blazing the trail on our journey to Mars,” said NASA Administrator Charlie Bolden, himself a former astronaut. “A few exceptionally talented men and women will become the astronauts chosen in this group who will once again launch to space from U.S. soil on American-made spacecraft.”

Applications opened Dec. 14, and closed Thursday, but that is just the beginning of an 18-month process that will end with the selection of 8-14 individuals for the opportunity to become astronaut candidates. NASA expects to announce its selections in mid-2017.

For more information about NASA astronauts, visit: www.nasa.gov/astronauts

For information about other NASA job opportunities, visit: www.nasa.gov/about/career

NASA Invites Public to Send Artwork to an Asteroid

RELEASE 16-019 (Click here for the full article) – 19 February 2016

2016feb19_16-019NASA is calling all space enthusiasts to send their artistic endeavors on a journey aboard NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft. This will be the first U.S. mission to collect a sample of an asteroid and return it to Earth for study.

OSIRIS-REx is scheduled to launch in September and travel to the asteroid Bennu. The #WeTheExplorers campaign invites the public to take part in this mission by expressing, through art, how the mission’s spirit of exploration is reflected in their own lives. Submitted works of art will be saved on a chip on the spacecraft. The spacecraft already carries a chip with more than 442,000 names submitted through the 2014 “Messages to Bennu” campaign.

“The development of the spacecraft and instruments has been a hugely creative process, where ultimately the canvas is the machined metal and composites preparing for launch in September,” said Jason Dworkin, OSIRIS-REx project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It is fitting that this endeavor can inspire the public to express their creativity to be carried by OSIRIS-REx into space.”

For details on how to include your submission on the mission to Bennu, go to: www.asteroidmission.org/WeTheExplorers

For more information on OSIRIS-Rex, visit: www.nasa.gov/osiris-rex

NASA News – NASA’s Kepler Telescope Discovers First Earth-Size Planet in ‘Habitable Zone’

Greetings fellow astrophiles,

Certainly NASA news worth posting! The constellation Cygnus returns to prime viewing in late Spring through the Summer and we’ll hope to have Kepler-186 found for the big Dob’s by then. Meantime, the NASA News Press Release is reproduced in its entirety below.

RELEASE 14-111 – April 17, 2014


Caption: Kepler-186f resides in the Kepler-186 system about 500 light-years from Earth in the constellation Cygnus. The system is also home to four inner planets, seen lined up in orbit around a host star that is half the size and mass of the sun. Image Credit: NASA Ames/SETI Institute/JPL-Caltech

Using NASA’s Kepler Space Telescope, astronomers have discovered the first Earth-size planet orbiting a star in the “habitable zone” — the range of distance from a star where liquid water might pool on the surface of an orbiting planet. The discovery of Kepler-186f confirms that planets the size of Earth exist in the habitable zone of stars other than our sun.

While planets have previously been found in the habitable zone, they are all at least 40 percent larger in size than Earth and understanding their makeup is challenging. Kepler-186f is more reminiscent of Earth.

“The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth,” said Paul Hertz, NASA’s Astrophysics Division director at the agency’s headquarters in Washington. “Future NASA missions, like the Transiting Exoplanet Survey Satellite and the James Webb Space Telescope, will discover the nearest rocky exoplanets and determine their composition and atmospheric conditions, continuing humankind’s quest to find truly Earth-like worlds.”

Although the size of Kepler-186f is known, its mass and composition are not. Previous research, however, suggests that a planet the size of Kepler-186f is likely to be rocky.

“We know of just one planet where life exists — Earth. When we search for life outside our solar system we focus on finding planets with characteristics that mimic that of Earth,” said Elisa Quintana, research scientist at the SETI Institute at NASA’s Ames Research Center in Moffett Field, Calif., and lead author of the paper published today in the journal Science. “Finding a habitable zone planet comparable to Earth in size is a major step forward.”


Caption: The diagram compares the planets of our inner solar system to Kepler-186, a five-planet star system about 500 light-years from Earth in the constellation Cygnus. The five planets of Kepler-186 orbit an M dwarf, a star that is is half the size and mass of the sun. Image Credit: NASA Ames/SETI Institute/JPL-Caltech

Kepler-186f resides in the Kepler-186 system, about 500 light-years from Earth in the constellation Cygnus. The system is also home to four companion planets, which orbit a star half the size and mass of our sun. The star is classified as an M dwarf, or red dwarf, a class of stars that makes up 70 percent of the stars in the Milky Way galaxy.

“M dwarfs are the most numerous stars,” said Quintana. “The first signs of other life in the galaxy may well come from planets orbiting an M dwarf.”

Kepler-186f orbits its star once every 130-days and receives one-third the energy from its star that Earth gets from the sun, placing it nearer the outer edge of the habitable zone. On the surface of Kepler-186f, the brightness of its star at high noon is only as bright as our sun appears to us about an hour before sunset.

“Being in the habitable zone does not mean we know this planet is habitable. The temperature on the planet is strongly dependent on what kind of atmosphere the planet has,” said Thomas Barclay, research scientist at the Bay Area Environmental Research Institute at Ames, and co-author of the paper. “Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth.”

The four companion planets, Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e, whiz around their sun every four, seven, 13, and 22 days, respectively, making them too hot for life as we know it. These four inner planets all measure less than 1.5 times the size of Earth.

The next steps in the search for distant life include looking for true Earth-twins — Earth-size planets orbiting within the habitable zone of a sun-like star — and measuring the their chemical compositions. The Kepler Space Telescope, which simultaneously and continuously measured the brightness of more than 150,000 stars, is NASA’s first mission capable of detecting Earth-size planets around stars like our sun.

Ames is responsible for 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 & 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.

The SETI Institute is a private, nonprofit organization dedicated to scientific research, education and public outreach. The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.

For more information about the Kepler mission, visit: www.nasa.gov/kepler


J.D. Harrington
Headquarters, Washington

Michele Johnson
Ames Research Center, Moffett Field, Calif.

Karen Randall
SETI Institute
650 960-4537

NASA news releases and other information are available automatically by sending an e-mail message with the subject line subscribe to hqnews-request@newsletters.nasa.gov. To unsubscribe from the list, send an e-mail message with the subject line unsubscribe to hqnews-request@newsletters.nasa.gov.

A Busy Day For Science @ NASA News – Voyager 1 Flies Out And Star Clusters Zoom In

Greetings fellow astrophiles!

There are untold numbers of places online that provide all kinds of astronomy news. The CNYO twitter feed is pushing 200 (following, that is. Still working on the follower count) accounts that range from UK Astronomy Clubs (they are exceptionally well organized on the other side of the pond) to equipment vendors to NASA astronauts. The same goes for RSS feeds from astronomy-centric news services, facebook groups, online magazines (or paper magazines with significant online contents), and a multitude of individuals hosting blog sites that report their own observing, study the news for proper amateur digestion, and generally produce really great content.

All that said, there is a lot of the same news online. With a large twitter feed count, you’ll see the same story a half-dozen times within an hour of its official reporting. Imagine following all the major news services to have them all post the same Associated Press tweet over and over and over again. One comes to question the veracity of the news services who happen to post articles hours or days after everyone else.

I subscribed a year ago to the NASA News Release Email List in the hopes of catching all of the major NASA happenings from the original source. The list is free to subscribe to and pumps out about 3000 news releases a year (some days being MUCH busier than others).

One can make their own subscription official by following the text at the footer of all their messages:

NASA news releases and other information are available automatically by sending an e-mail message with the subject line subscribe to hqnews-request@newsletters.nasa.gov. 
To unsubscribe from the list, send an e-mail message with the subject line unsubscribe to hqnews-request@newsletters.nasa.gov.

This past September 12 was a banner day for NASA News, as NASA made the official announcement of Voyager 1’s departure (sort of) from the Solar System and Hubble scientists reported the largest yet observed cluster of globular clusters (imagine having multiple M13’s in the same low-power field of view!) – featuring a rare image to complement the standard text-only announcements. I’ve included the two releases below (with an extra image showing the position of Voyager 1 – including an actual image of the distant traveler obtained using the Very Long Baseline Array (VLBA) and Green Bank Telescope (GBT).

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

Jia-Rui C. Cook – Jet Propulsion Laboratory, Pasadena, Calif. – 818-354-0850 – jccook@jpl.nasa.gov

RELEASE 13-280 – NASA Spacecraft Embarks on Historic Journey into Interstellar Space

NASA’s Voyager 1 spacecraft officially is the first human-made object to venture into interstellar space. The 36-year-old probe is about 12 billion miles (19 billion kilometers) from our sun.

New and unexpected data indicate Voyager 1 has been traveling for about one year through plasma, or ionized gas, present in the space between stars. Voyager is in a transitional region immediately outside the solar bubble, where some effects from our sun are still evident. A report on the analysis of this new data, an effort led by Don Gurnett and the plasma wave science team at the University of Iowa, Iowa City, is published in Thursday’s edition of the journal Science.

“Now that we have new, key data, we believe this is mankind’s historic leap into interstellar space,” said Ed Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. “The Voyager team needed time to analyze those observations and make sense of them. But we can now answer the question we’ve all been asking — ‘Are we there yet?’ Yes, we are.”

Voyager 1 first detected the increased pressure of interstellar space on the heliosphere, the bubble of charged particles surrounding the sun that reaches far beyond the outer planets, in 2004. Scientists then ramped up their search for evidence of the spacecraft’s interstellar arrival, knowing the data analysis and interpretation could take months or years.

Voyager 1 does not have a working plasma sensor, so scientists needed a different way to measure the spacecraft’s plasma environment to make a definitive determination of its location. A coronal mass ejection, or a massive burst of solar wind and magnetic fields, that erupted from the sun in March 2012 provided scientists the data they needed. When this unexpected gift from the sun eventually arrived at Voyager 1’s location 13 months later, in April 2013, the plasma around the spacecraft began to vibrate like a violin string. On April 9, Voyager 1’s plasma wave instrument detected the movement. The pitch of the oscillations helped scientists determine the density of the plasma. The particular oscillations meant the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere. Density of this sort is to be expected in interstellar space.

The plasma wave science team reviewed its data and found an earlier, fainter set of oscillations in October and November 2012. Through extrapolation of measured plasma densities from both events, the team determined Voyager 1 first entered interstellar space in August 2012.

“We literally jumped out of our seats when we saw these oscillations in our data — they showed us the spacecraft was in an entirely new region, comparable to what was expected in interstellar space, and totally different than in the solar bubble,” Gurnett said. “Clearly we had passed through the heliopause, which is the long-hypothesized boundary between the solar plasma and the interstellar plasma.”

The new plasma data suggested a timeframe consistent with abrupt, durable changes in the density of energetic particles that were first detected on Aug. 25, 2012. The Voyager team generally accepts this date as the date of interstellar arrival. The charged particle and plasma changes were what would have been expected during a crossing of the heliopause.

“The team’s hard work to build durable spacecraft and carefully manage the Voyager spacecraft’s limited resources paid off in another first for NASA and humanity,” said Suzanne Dodd, Voyager project manager, based at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif. “We expect the fields and particles science instruments on Voyager will continue to send back data through at least 2020. We can’t wait to see what the Voyager instruments show us next about deep space.”

Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft. It is about 9.5 billion miles (15 billion kilometers) away from our sun.

Voyager mission controllers still talk to or receive data from Voyager 1 and Voyager 2 every day, though the emitted signals are currently very dim, at about 23 watts — the power of a refrigerator light bulb. By the time the signals get to Earth, they are a fraction of a billion-billionth of a watt. Data from Voyager 1’s instruments are transmitted to Earth typically at 160 bits per second, and captured by 34- and 70-meter NASA Deep Space Network (DSN) stations. Traveling at the speed of light, a signal from Voyager 1 takes about 17 hours to travel to Earth. After the data are transmitted to JPL and processed by the science teams, Voyager data are made publicly available.

“Voyager has boldly gone where no probe has gone before, marking one of the most significant technological achievements in the annals of the history of science, and adding a new chapter in human scientific dreams and endeavors,” said John Grunsfeld, NASA’s associate administrator for science in Washington. “Perhaps some future deep space explorers will catch up with Voyager, our first interstellar envoy, and reflect on how this intrepid spacecraft helped enable their journey.”

Scientists do not know when Voyager 1 will reach the undisturbed part of interstellar space where there is no influence from our sun. They also are not certain when Voyager 2 is expected to cross into interstellar space, but they believe it is not very far behind.

JPL built and operates the twin Voyager spacecraft. The Voyagers Interstellar Mission is a part of NASA’s Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA’s Science Mission Directorate in Washington. NASA’s DSN, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

The cost of the Voyager 1 and Voyager 2 missions — including launch, mission operations and the spacecraft’s nuclear batteries, which were provided by the Department of Energy — is about $988 million through September.

For a sound file of the oscillations detected by Voyager in interstellar space, animations and other information, visit: www.nasa.gov/voyager

For an image of the radio signal from Voyager 1 on Feb. 21 by the National Radio Astronomy Observatory’s Very Long Baseline Array, which links telescopes from Hawaii to St. Croix, visit: www.nrao.edu (image below – click for a large version).


J.D. Harrington – Headquarters, Washington – 202-358-5241 – j.d.harrington@nasa.gov

Ray Villard – Space Telescope Science Institute, Baltimore, Md. – 410-338-4514 – villard@stsci.edu

RELEASE 13-282 – Hubble Uncovers Largest Known Group of Star Clusters, Clues to Dark Matter


Hubble Space Telescope image of largest known population of globular clusters, in Abell 1689 galaxy grouping. Image Credit: NASA/ESA

NASA’s Hubble Space Telescope has uncovered the largest known population of globular star clusters, an estimated 160,000, swarming like bees inside the crowded core of the giant grouping of galaxies known as Abell 1689.

An international team of astronomers used Hubble’s Advanced Camera for Surveys to discover this bounty of stellar fossils and confirm such compact groupings can be used as reliable tracers for dark matter, the invisible gravitational scaffolding on which galaxies are built.

“We show how the relationship between globular clusters and dark matter depends on the distance from the center of the galaxy grouping,” Karla Alamo-Martinez of the Center for Radio Astronomy and Astrophysics of the National Autonomous University of Mexico in Morelia. “In other words, if you know how many globular clusters are within a certain distance, we can give you an estimate of the amount of dark matter.”

Alamo-Martinez is lead author of a paper on the findings published online Sept. 10 and appearing in the Sept. 20 print edition of The Astrophysical Journal, and part of a team led by John Blakeslee of National Research Council Canada’s Herzberg Institute of Astrophysics at the Dominion Radio Astrophysical Observatory in Victoria, British Columbia.

Globular clusters, dense bunches of hundreds of thousands of stars, are the homesteaders of galaxies. They contain some of the oldest surviving stars in the universe. Almost 95 percent of globular cluster formation occurred within the first 1 billion to 2 billion years after our universe was born in the theorized Big Bang 13.8 billion years ago.

Studying globular clusters is critical to understanding the early, intense star-forming events that mark galaxy formation. Understanding dark matter can yield clues on how large structures such as galaxies and galaxy clusters were assembled billions of years ago.

The globular star cluster in Abell 1689 is roughly twice as large as any other population found in previous globular cluster surveys — in comparison, our Milky Way galaxy hosts about 150 — and constitutes the most distant such systems ever studied, at 2.25 billion light-years away. The Hubble study shows most of the globular clusters in Abell 1689 formed near the center of the galaxy grouping, which contains a deep well of dark matter. The farther away from the galaxy core Hubble looked, the fewer globular clusters it detected. This observation corresponded with a comparable drop in the amount of dark matter, based on previous research.

“The globular clusters are fossils of the earliest star formation in Abell 1689, and our work shows they were very efficient in forming in the denser regions of dark matter near the center of the galaxy cluster,” Blakeslee said. “Our findings are consistent with studies of globular clusters in other galaxy clusters, but extend our knowledge to regions of higher dark matter density.”

Peering deep inside the heart of Abell 1689, Hubble detected the visible-light glow of 10,000 globular clusters, some as dim as 29th magnitude, which is 1 one-billionth the faintness of the dimmest star that can be seen with the naked eye. Based on that number, Blakeslee’s team estimated that more than 160,000 globular clusters are huddled within a diameter of 2.4 million light-years.

“Even though we are looking deep into the cluster, we’re only seeing the brightest globular clusters, and only near the center of Abell 1689 where Hubble was pointed,” he said.

For images and more information about the Abell 1689, visit:

www.nasa.gov/hubble or hubblesite.org/news/2013/36

The NASA News Release service is a great way to keep track of goings on in the nation’s space program, but goes much farther into all areas of NASA research, including climate research, geology, engineering, and administration. I encourage interested parties to sign up and get at least some of their space science news first-hand – then complain about all the twitter feeds taking so many minutes to report the same.

NASA Space Place – Partnering to Solve Saturn’s Mysteries

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in December, 2012.

By Diane K. Fisher

2013february2_spaceplaceFrom December 2010 through mid-summer 2011, a giant storm raged in Saturn‘s northern hemisphere. It was clearly visible not only to NASA’s Cassini spacecraft orbiting Saturn, but also astronomers here on Earth—even those watching from their back yards. The storm came as a surprise, since it was about 10 years earlier in Saturn’s seasonal cycle than expected from observations of similar storms in the past. Saturn’s year is about 30 Earth years. Saturn is tilted on its axis (about 27° to Earth’s 23°), causing it to have seasons as Earth does.

But even more surprising than the unseasonal storm was the related event that followed.

First, a giant bubble of very warm material broke through the clouds in the region of the now-abated storm, suddenly raising the temperature of Saturn’s stratosphere over 150 °F. Accompanying this enormous “burp” was a sudden increase in ethylene gas. It took Cassini’s Composite Infrared Spectrometer instrument to detect it.

According to Dr. Scott Edgington, Deputy Project Scientist for Cassini, “Ethylene [C2H4] is normally present in only very low concentrations in Saturn’s atmosphere and has been very difficult to detect. Although it is a transitional product of the thermochemical processes that normally occur in Saturn’s atmosphere, the concentrations detected concurrent with the big ‘burp’ were 100 times what we would expect.”

So what was going on?

Chemical reaction rates vary greatly with the energy available for the process. Saturn’s seasonal changes are exaggerated due to the effect of the rings acting as venetian blinds, throwing the northern hemisphere into shade during winter. So when the Sun again reaches the northern hemisphere, the photochemical reactions that take place in the atmosphere can speed up quickly. If not for its rings, Saturn’s seasons would vary as predictably as Earth’s.

But there may be another cycle going on besides the seasonal one. Computer models are based on expected reaction rates for the temperatures and pressures in Saturn’s atmosphere, explains Edgington. However, it is very difficult to validate those models here on Earth. Setting up a lab to replicate conditions on Saturn is not easy!

Also contributing to the apparent mystery is the fact that haze on Saturn often obscures the view of storms below. Only once in a while do storms punch through the hazes. Astronomers may have previously missed large storms, thus failing to notice any non-seasonal patterns.

As for atmospheric events that are visible to Earth-bound telescopes, Edgington is particularly grateful for non-professional astronomers. While these astronomers are free to watch a planet continuously over long periods and record their finding in photographs, Cassini and its several science instruments must be shared with other scientists. Observation time on Cassini is planned more than six months in advance, making it difficult to immediately train it on the unexpected. That’s where the volunteer astronomers come in, keeping a continuous watch on the changes taking place on Saturn.

Edgington says, “Astronomy is one of those fields of study where amateurs can contribute as much as professionals.”

Go to saturn.jpl.nasa.gov to read about the latest Cassini discoveries. For kids, The space Place has lots of ways to explore Saturn at spaceplace.nasa.gov/search/cassini.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.


Caption: This false-colored Cassini image of Saturn was taken in near-infrared light on January 12, 2011. Red and orange show clouds deep in the atmosphere. Yellow and green are intermediate clouds. White and blue are high clouds and haze. The rings appear as a thin, blue horizontal line.

About NASA Space Place

The goal of the NASA Space Place is “to inform, inspire, and involve children in the excitement of science, technology, and space exploration.” More information is available at their website: http://spaceplace.nasa.gov/