NASA Planetary Science Trio Honored as ‘Best of What’s New’ in 2011- Curiosity/Dawn/MESSENGER


A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.

The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.

Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.

“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.

Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.

“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.

Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.

Asteroid Vesta from Dawn - Exquisite Clarity from a formerly Fuzzy Blob
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Before Dawn, Vesta was just a fuzzy blob in the most powerful telescopes. Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body before firing up the ion propulsion system to break orbit and speed to Ceres, the largest Asteroid. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.

“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”

JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.

Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.

“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.

“MSL packs the most bang for the buck yet sent to Mars.”

Last View of Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC.
Curiosity just before Encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer

Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.

“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”

“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.

MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia.

Curiosity Mars Science Laboratory rover soars to Mars atop an Atlas V rocket on Nov. 26 at 10:02 a.m. EST from Cape Canaveral, Florida. Credit: Ken Kremer

MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.

Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.

“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington

“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”

The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Read more about the Popular Science citations and awards here
Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:

Curiosity Mars Rover Launch Gallery – Photos and Videos
Curiosity Majestically Blasts off on ‘Mars Trek’ to ascertain ‘Are We Alone?
Dawn Discovers Surprise 2nd Giant South Pole Impact Basin at Strikingly Dichotomous Vesta
Amazing New View of the Mt. Everest of Vesta
MESSENGER Unveiling Mercurys Hidden Secrets

Ed Weiler – NASA Science Leader and Hubble Chief Scientist Retires


Ed Weiler, NASA’s Science leader in charge of the robotic missions that continually produce scientific breakthroughs that amaze all humanity and longtime Chief Scientist on the Hubble Space Telescope that has completely revolutionized our understanding of humanities place in the Universe, retired today (Sept. 30) from NASA after a distinguished career spanning almost 33 years.

Weiler is departing NASA during what has been dubbed the “Year of Space Science”- the best year ever for NASA Space Science research. The two most recent successes are the launch of JUNO to Jupiter and the twin GRAIL probes to the Moon. Blastoff of the Curiosity Mars Science Laboratory rover is slated for late November 2011.

Weiler’s official title is associate administrator of NASA’s Science Mission Directorate (SMD) at agency Headquarters in Washington, DC. In that capacity he was responsible for overseeing NASA’s science and research programs in Earth science, heliophysics, planetary science and astrophysics.

Weiler was appointed to lead SMD in 2008. He holds this position now for the second time after serving in between as Director of NASA Goddard Spaceflight Center in Greenbelt, Maryland from 2004 to 2008. His earlier stint as associate administrator lasted from 1998 to 2004 for what was then called the Space Science Enterprise.

Dr. Ed Weiler, NASA Associate Administrator for the Science Mission Directorate. Credit: NASA/Bill Ingalls

Probably the job he loved best was as Chief Scientist of the Hubble Space Telescope from 1979 to 1998, until he was promoted to the top rung of NASA management.

I was very lucky to meet and chat with Ed Weiler while I was covering the final space shuttle flight – STS-125 – to repair and upgrade Hubble. STS 125 blasted off in May 2009 and accomplished every single objective to catapult Hubble to the apex of its capabilities.

At the recent launch of the twin GRAIL lunar mapping probes, I spoke with Weiler about a wide range of NASA missions. Watch for my upcoming interview with Ed.

Weiler is very hopeful that Hubble will continue to operate for several more years at least.

NASA issued this statement from NASA Administrator Charles Bolden, “Ed leaves an enduring legacy of pride and success that forever will remain a part of NASA’s science history. His leadership helped inspire the public with each new scientific discovery, and enabled NASA to move forward with new capabilities to continue to explore our solar system and beyond.”

The successes under Weiler’s leadership include NASA’s great observatory missions, unprecedented advances in Earth science and extensive exploration of Mars and other planets in our solar system. These advances have rewritten science textbooks and earned enormous support for NASA’s science programs from the general public.

The Mars rovers Spirit and Opportunity are just one example of the science missions approved and funded during Weiler’s tenure.

Weiler’s leadership has been instrumental in securing continued support and funding for NASA Space Science from Congress and the White House. He has received numerous prestigious awards including the NASA Distinguished Service Medal and several Presidential Rank Awards for Meritorious Executive and Distinguished Executive.

Ed Weiler remembers Spirit at JPL symposium. Credit: AP

Space Spectacular — Rotation Movies of Vesta

Take us into orbit Mr. Sulu!

The Dawn science team has released two spectacular rotation movies of the entire globe of the giant asteroid Vesta. The flyover videos give the distinct impression that you are standing on the bridge of the Starship Enterprise and gazing at the view screen as the ship enters orbit about a new planet for the first time and are about to begin an exciting new journey of exploration and discovery of the body you’re looking at below.

Thanks to NASA, DLR, ASI and Dawn’s international science and engineering team, we can all join the away team on the expedition to unveil Vesta’s alluring secrets.

Click the start button and watch protoplanet Vesta’s striking surface moving beneath from the perspective of Dawn flying above – in the initial survey orbit at an altitude of 2700 kilometers (1700 miles). Vesta is the second most massive object in the main asteroid belt and Dawn’s first scientific conquest.

Another video below was compiled from images taken earlier on July 24, 2011 from a higher altitude after Dawn first achieved orbit about Vesta and revealed that the northern and southern hemispheres are totally different.

The array of images in the videos was snapped by Dawn’s framing camera which was provided by the German Aerospace Center (DLR). The team then created a shape model from the images, according to Dr. Carol Raymond, Dawn’s Deputy Principal Investigator from NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The shape model will aid in studying Vesta’s strikingly diverse features of mountains, ridges, valley’s, scarps, cliffs, grooves, craters, even a ‘snowman’ and much more.

Notice that not all of Vesta is illuminated – because it’s northern winter at the asteroid. Vesta has seasons like Earth and the northern polar region in now in perpetual darkness. Data is collected over the day side and radioed back to Earth over the night side.

“On Vesta right now, the southern hemisphere is facing the sun, so everywhere between about 52 degrees north latitude and the north pole is in a long night,” says Dr. Rayman, Dawn’s Chief Engineer from JPL. “That ten percent of the surface is presently impossible to see. Because Dawn will stay in orbit around Vesta as together they travel around the sun, in 2012 it will be able to see some of this hidden scenery as the seasons advance.”

Another movie highlight is a thorough look at the gigantic south pole impact basin. The circular feature is several hundred miles wide and may have been created by a cosmic collision eons ago that excavated massive quantities of material and basically left Vesta lacking a south pole.


The massive feature was discovered in images taken by the Hubble Space Telescope several years ago and mission scientists have been eager to study it up close in a way that’s only possible from orbit. Dawn’s three science instruments will investigate the south pole depression in detail by collecting high resolution images and spectra which may reveal the interior composition of Vesta.

Dawn entered the survey orbit on Aug. 11 and completed seven revolutions of 69 hours each on Sept. 1. It transmitted more than 2,800 pictures from the DLR framing camera covering the entire illuminated surface and also collected over three million visible and infrared spectra from the VIR spectrometer – provided by ASI, the Italian Space Agency. This results exceeded the mission objectives.

The Dawn spacecraft is now spiraling down closer using its ion propulsion system to the next mapping orbit – known as HAMO – four times closer than the survey orbit and only some 680 km (420 miles) above the surface.

Read Ken’s continuing features about Dawn
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin


NASA’s Dawn Asteroid Orbiter is now spiraling down ever closer to the protoplanet Vesta – since arriving on July 16 – and capturing magnificent new high resolution images of the huge impact basin at the South Pole that dominates the surface. See enhanced image here.

The Dawn team just released a new image taken by the framing camera on July 18 as the orbiter flew from the day side to the night side at an altitude of 10,500 kilometers above Vesta, the second most massive body in the main Asteroid Belt between Mars and Jupiter.

NASA's Dawn spacecraft obtained this image centered on the south pole with its framing camera on July 18, 2011. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“I find this picture very dramatic !” exclaimed Dr. Marc Rayman, Dawn Chief Engineer from the NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in an interview with Universe Today.

Dawn acquired this image after it had flown past the terminator and its orbit began taking it over the night side of Vesta.”

“After having this view, the spacecraft resumed gradually spiraling around its new home, heading for survey orbit where it will begin intensive observations of Vesta,” Rayman told me.

Dawn will reach the initial science survey orbit in early August, approximately 1700 miles above the battered surface. Vesta turns on its axis once very five hours and 20 minutes.

Vesta suffered an enormous cosmic collision eons ago that apparently created a gigantic impact basin in the southern hemisphere and blasted enormous quantities of soil, rocks and dust into space. Some 5% of all meteorites found on Earth originate from Vesta.

“The south pole region was declared to be a large impact basin after the Hubble Space Telescope (HST) data and images were obtained,” elaborated Prof. Chris Russell, Dawn Principal Investigator from UCLA.

“Now that we have higher resolution images we see that this region is unlike any other large impact on a small body but much of our experience here is on icy bodies of similar size,” Russell told me.

Dawn’s new images of Vesta taken at close range from just a few thousand miles away, now vastly exceed those taken by Hubble as it circled in Earth orbit hundreds of millions of miles away and may cause the science team to reevaluate some long held theories.

“The team is looking forward to obtaining higher resolution data over this region to look for confirmatory evidence for the impact hypothesis. They are not yet willing to vote for or against the HST interpretation. Needless to say the team got very excited by this image,” said Russell.

Dawn will orbit Vesta for one year before heading to its final destination, the Dwarf Planet Ceres.

Simulated View of Vesta from Dawn on July 23, 2011. Credit: NASA

Read my prior features about Dawn
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Dawn Closing in on Asteroid Vesta as Views Exceed Hubble


A new world in our Solar System is about to be unveiled for the first time – the mysterious protoplanet Vesta, which is the second most massive object in the main Asteroid Belt between Mars and Jupiter.

NASA’s Dawn Asteroid orbiter has entered its final approach phase to Vesta and for the first time is snapping images that finally exceed those taken several years ago by the iconic Hubble Space Telescope.

“The Dawn science campaign at Vesta will unveil a mysterious world, an object that can tell us much about the earliest formation of the planets and the solar system,” said Jim Adams, Deputy Director, Planetary Science Directorate at NASA HQ at a briefing for reporters.

Vesta holds a record of the earliest history of the solar system. The protoplanet failed to form into a full planet due to its close proximity to Jupiter.

Check out this amazing NASA approach video showing Vesta growing in Dawn’s eyes. The compilation of navigation images from Dawn’s framing camera spans about seven weeks from May 3 to June 20 was released at the NASA press briefing by the Dawn science team.

Dawn’s Approach to Vesta – Video

Best View from Hubble – Video

Be sure to notice that Vesta’s south pole is missing due to a cataclysmic event eons ago that created a massive impact crater – soon to be unveiled in astounding clarity. Some of that colossal debris sped toward Earth and survived the terror of atmospheric entry. Planetary Scientists believe that about 5% of all known meteorites originated from Vesta, based on spectral evidence.

After a journey of four years and 1.7 billion miles, NASA’s revolutionary Dawn spacecraft thrusting via exotic ion propulsion is now less than 95,000 miles distant from Vesta, shaping its path through space to match the asteroid.

The internationally funded probe should be captured into orbit on July 16 at an initial altitude of 9,900 miles when Vesta is some 117 million miles from Earth.

After adjustments to lower Dawn to an initial reconnaissance orbit of approximately 1,700 miles, the science campaign is set to kick off in August with the collection of global color images and spectral data including compositional data in different wavelengths of reflected light.

Dawn Approaching Vesta
Dawn obtained this image on June 20, 2011. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI and NASA/ESA/STScI/UMd

Dawn will spend a year investigating Vesta. It will probe the protoplanet using its three onboard science instruments – provided by Germany, Italy and the US – and provide researchers with the first bird’s eye images, global maps and detailed scientific measurements to elucidate the chemical composition and internal structure of a giant asteroid.

“Navigation images from Dawn’s framing camera have given us intriguing hints of Vesta, but we’re looking forward to the heart of Vesta operations, when we begin officially collecting science data,” said Christopher Russell, Dawn principal investigator, at the University of California, Los Angeles (UCLA). “We can’t wait for Dawn to peel back the layers of time and reveal the early history of our solar system.”

Because Dawn is now so close to Vesta, the frequency of imaging will be increased to twice a week to achieve the required navigational accuracy to successfully enter orbit., according to Marc Rayman, Dawn Chief Engineer at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

“By the beginning of August, it will see Vesta with more than 100 times the clarity that Hubble could ever obtain,” says Rayman.

Vesta in Spectrometer View
On June 8, 2011, the visible and infrared mapping spectrometer aboard NASA's Dawn spacecraft captured the instrument's first images of Vesta that are larger than a few pixels, from a distance of about 218,000 miles (351,000 kilometers). The image was taken for calibration purposes. An image obtained in the visible part of the light spectrum appears on the left. An image obtained in the infrared spectrum, at around 3 microns in wavelength, appears on the right. The spatial resolution of this image is about 60 miles (90 kilometers) per pixel. Credit: NASA/JPL-Caltech/UCLA/ASI/INAF

Dawn will gradually edge down closer to altitudes of 420 miles and 120 miles to obtain ever higher resolution orbital images and spectal data before spiraling back out and eventually setting sail for Ceres, the largest asteroid of them all.

Dawn will be the first spacecraft to orbit two celestial bodies, only made possible via the ion propulsion system. With a wingspan of 65 feet, it’s the largest planetary mission NASA has ever launched.

“We’ve packed our year at Vesta chock-full of science observations to help us unravel the mysteries of Vesta,” said Carol Raymond, Dawn’s deputy principal investigator at JPL.

“This is an unprecedented opportunity to spend a year at a body that we know almost nothing about,” added Raymond. “We are very interested in the south pole because the impact exposed the deep interior of Vesta. We’ll be able to look at features down to tens of meters so we can decipher the geologic history of Vesta.”

Possible Piece of Vesta
Scientists believe a large number of the meteorites that are found on Earth originate from the protoplanet Vesta. A cataclysmic impact at the south pole of Vesta, the second most massive object in the main asteroid belt, created an enormous crater and excavated a great deal of debris. Some of that debris ended up as other asteroids and some of it likely ended up on Earth. Image Credit: NASA/JPL-Caltech
Dawn Trajectory and Current Location on June 29, 2011. Credt: NASA/JPL
Dawn launch on September 27, 2007 by a Delta II rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

Read my prior feature about Dawn here

Hubble Takes a Spectacular Look Inside the Eagle Nebula



There are some stellar powerhouses inside the Eagle Nebula, and Hubble has captured a collection of these hot, blue stars. These dazzling stars are an open star cluster called NGC 6611, whose fierce ultraviolet glow make the surrounding Eagle Nebula glow brightly. But there are also areas in this image that look dark and empty. Are those areas just empty? No, they are actually very dense regions of gas and dust, which obstruct light from passing through.

Hubble astronomers say that many of these dark areas may be hiding the sites of the early stages of star formation, before the fledgling stars clear away their surroundings and burst into view. Dark nebulae, large and small, are dotted throughout the Universe. If you look up to the Milky Way with the naked eye from a dark, remote site, you can easily spot some huge dark nebulae blocking the background starlight.

This region in the Eagle Nebula formed about 5.5 million years ago and is found approximately 6,500 light-years from the Earth. The cluster and the associated nebula together are also known as Messier 16.

Astronomers refer to areas like the Eagle Nebula as HII regions. This is the scientific notation for ionised hydrogen from which the region is largely made. Extrapolating far into the future, this HII region will eventually disperse, helped along by shockwaves from supernova explosions as the more massive young stars end their brief but brilliant lives.

This picture was created from images from Hubble’s Wide Field Channel of the Advanced Camera for Surveys through the unusual combination of two near-infrared filters (F775W, colored blue, and F850LP, colored red). The image has also been subtly colorized using a ground-based image taken through more conventional filters. The Hubble exposure times were 2000 s in both cases and the field of view is about 3.2 arcminutes across.

Source: ESA/Space Telescope

‘Ring’ in the Holidays with New Hubble Bubble Image


From a Hubble/ESA press release:

A festive, delicate ring –photographed by the Hubble Space Telescope — appears to float serenely in the depths of space, but this apparent calm hides an inner turmoil. The gaseous envelope formed as the expanding blast wave and ejected material from a supernova tore through the nearby interstellar medium. Called SNR B0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light-years from Earth.

Ripples seen in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or possibly be driven from the interior by fragments from the initial explosion. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Astronomers have concluded that the explosion was an example of an especially energetic and bright variety of supernova. Known as Type Ia, such supernova events are thought to result when a white dwarf star in a binary system robs its partner of material, taking on more mass than it is able to handle, so that it eventually explodes.

Hubble’s Advanced Camera for Surveys observed the supernova remnant on 28 October 2006 with a filter that isolates light from the glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble’s Wide Field Camera 3 on 4 November 2010.

With an age of about 400 years, the supernova might have been visible to southern hemisphere observers around the year 1600, although there are no known records of a “new star” in the direction of the LMC near that time. A much more recent supernova in the LMC, SN 1987A, did catch the eye of Earth viewers and continues to be studied with ground- and space-based telescopes, including Hubble.

Hubble Predicts the Future of Omega Centauri


Using four years of data from the Hubble Space Telescope’s Advanced Camera for Surveys, astronomers have made the most accurate measurements of the movement of stars in the globular cluster Omega Centauri, and now can predict their movements for the next 10,000 years. This “beehive” of stars is tightly crammed together, so resolving the individual stars was a job that perhaps only Hubble could do. “It takes high-speed, sophisticated computer programs to measure the tiny shifts in the positions of the stars that occur in only four years’ time,” says astronomer Jay Anderson of the Space Telescope Science Institute in Baltimore, Md., who conducted the study with fellow Institute astronomer Roeland van der Marel. “Ultimately, though, it is Hubble’s razor-sharp vision that is the key to our ability to measure stellar motions in this cluster.”

Astronomers say that the precise measurement of star motions in giant clusters can yield insights into how stellar groupings formed in the early universe, and whether an “intermediate mass” black hole, one roughly 10,000 times as massive as our Sun, might be lurking among the stars.

Analyzing archived images taken over a four-year period by Hubble’s astronomers have made the most accurate measurements yet of the motions of more than 100,000 cluster inhabitants, the largest survey to date to study the movement of stars in any cluster.

The astronomers used the Hubble images, which were taken in 2002 and 2006, to make a movie simulation of the frenzied motion of the cluster’s stars. The movie shows the stars’ projected migration over the next 10,000 years.

Omega Centauri is the biggest and brightest globular cluster in the Milky Way, and one of the few that can be seen by the unaided eye. It is located in the constellation Centaurus, Omega Centauri, so is viewable in the southern skies, and is one of about 150 such clusters in our Milky Way Galaxy.

In this video below, astronomers Jay Anderson and Roeland van der Marel discuss their in-depth study of the giant cluster Omega Centauri.

Source: HubbleSite

Astronomers Now Closer to Understanding Dark Energy

Dark Energy

Understanding something we can’t see has been a problem that astronomers have overcome in the past. Now, a group of scientists believe a new technique will meet the challenge of helping to solve one of the biggest mysteries in cosmology today: understanding the nature of dark energy. Using the strong gravitational lensing method — where a massive galaxy cluster acts as a cosmic magnifying lens — an international team of astronomers have been able to study elusive dark energy for the first time. The team reports that when combined with existing techniques, their results significantly improve current measurements of the mass and energy content of the universe.

Using data taken by the Hubble Space Telescope as well as ground-based telescopes, the team analyzed images of 34 extremely distant galaxies situated behind Abell 1689, one of the biggest and most massive known galaxy clusters in the universe.

Through the gravitational lens of Abell 1689, the astronomers, led by Eric Jullo from JPL and Priyamvada Natarajan from Yale University, were able to detect the faint, distant background galaxies—whose light was bent and projected by the cluster’s massive gravitational pull—in a similar way that the lens of a magnifying lens distorts an object’s image.

Using this method, they were able to reduce the overall error in its equation-of-state parameter by 30 percent, when combined with other methods.

The way in which the images were distorted gave the astronomers clues as to the geometry of the space that lies between the Earth, the cluster and the distant galaxies. “The content, geometry and fate of the universe are linked, so if you can constrain two of those things, you learn something about the third,” Natarajan said.

The team was able to narrow the range of current estimates about dark energy’s effect on the universe, denoted by the value w, by 30 percent. The team combined their new technique with other methods, including using supernovae, X-ray galaxy clusters and data from the Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft, to constrain the value for w.

“Dark energy is characterized by the relationship between its pressure and its density: this is known as its equation of state,” said Jullo. “Our goal was to try to quantify this relationship. It teaches us about the properties of dark energy and how it has affected the development of the Universe.”

Dark energy makes up about 72 percent of all the mass and energy in the universe and will ultimately determine its fate. The new results confirm previous findings that the nature of dark energy likely corresponds to a flat universe. In this scenario, the expansion of the universe will continue to accelerate and the universe will expand forever.

The astronomers say the real strength of this new result is that it devises a totally new way to extract information about the elusive dark energy, and it offers great promise for future applications.

According to the scientists, their method required multiple, meticulous steps to develop. They spent several years developing specialized mathematical models and precise maps of the matter — both dark and “normal” — that together constitute the Abell 1689 cluster.

The findings appear in the August 20 issue of the journal Science.

Sources: Yale University, Science Express. ESA Hubble.

New Hubble Images Show Pluto is Changing

Pluto-philes (and astronomers, too) have always bemoaned the fact that the best image of the principal dwarf planet wase just a fuzzy, pixelized haze. Bemoan no more. The most detailed look to date of the entire surface of Pluto has been constructed from hundreds of images taken by the Hubble Space Telescope. The images were taken during 2002 to 2003, and it took four years of computer crunching and software tweaking to create the global images. Surprisingly, the images show Pluto changed noticeably during the two-year photo shoot; the dwarf planet’s color became “redder,” and astronomers could see Pluto’s ice sheets were shifting.

“These Hubble pictures represent a true-color appearance of what you would see if you were near Pluto, comparable to looking at our own Moon with the naked eye,” said principal investigator Marc Buie of the Southwest Research Institute. “We now know we’re looking at something that has the biggest surface changes of any object in our solar system.”

The pictures show nitrogen ice growing and shrinking, getting brighter in the north and darker in the south.

Buie and planet hunter Mike Brown from Caltech introduced the Hubble images during a teleconference with reporters today, and emphasized how surprised they were with the changes seen on Pluto in just a relatively short period of time. Even accounting for seasonal changes, seasons can last 120 years in some regions of Pluto.

The top picture was taken in 1994 by the European Space Agency’s Faint Object Camera. The bottom image was taken in 2002-2003 by the Advanced Camera for Surveys. The dark band at the bottom of each map is the region that was hidden from view at the time the data were taken. Credit: NASA, ESA, and M. Buie (Southwest Research Institute)

They said the images underscore that Pluto is not simply a ball of ice and rock but a dynamic world that undergoes dramatic atmospheric changes. While they believe the changes are driven by the seasons, it may mostly come from how quickly things can change on Pluto. The seasons are propelled as much by the planet’s 248-year elliptical orbit as its axial tilt — unlike Earth where the tilt alone drives seasons. On Pluto spring transitions to polar summer quickly in the northern hemisphere because Pluto is moving faster along its orbit when it is closer to the Sun.

“If Earth had such an extreme orbit, and we were experiencing a nice springtime day with 60-70 degree F temperatures, as the orbit changed it could suddenly drop to -90 degrees F,” said Brown.

There is also a mysterious bright spot on the center of Pluto, which has been observed in earlier images. But the spot is unusually rich in carbon monoxide frost.

Click here to see a video of Pluto rotating.

The astronomers said Pluto is so small and distant that the task of resolving the surface is as challenging as trying to see the markings on a soccer ball 40 miles away. Buie said we won’t have a better look at Pluto until the New Horizon’s spacecraft is six months away from the dwarf planet in 2015.

The images were taken with the Advanced Camera for Surveys on HST, and the 348 images taken in 2002 and 2003 were the last ones taken of Pluto with high enough resolution to be useful. “I had time allocated two years ago to look at Pluto, which came just three or four weeks after the high resolution camera failed,” Buie. “That was very disappointing.”

But the images do show Pluto is significantly redder than it had been for the past several decades. Astronomers use the word “red” to mean it reflects more red light than blue or green light. To the human eye, Pluto has a yellowish-orange color, and is about 20% redder than it used to be. “It’s not as red as the surface of Mars, but more red than Io,” Buie said.

Red is usually associated with carbon. The astronomers said there is also methane, which is not usually stable in an environment like Pluto’s.

“This business about the color change had me scared for awhile,” Buie confessed. “I got the result years ago, but it was so hard to understand and believe. I’m still nervous about it. It could be that I completely screwed this up, but I can tell you Charon is on the same images, and Charon has the same color throughout but Pluto changed. I don’t’ know how the camera system on HST could have given me the wrong colors on Pluto.”

This was previously the best image of Pluto, taken in 2000 by HST. Credit: Eliot Young (SwRI) et al., NASA

Someone suggested that Pluto is reddening because of its recent demotion from full planethood. “Yes, people have said that Pluto is mad at me,” said Brown, who has the nickname of the “Pluto killer” because he discovered other Kuiper Belt objects which led to the new class of dwarf planets.

“For a long time Pluto was this lonely oddball that we didn’t have anything else to compare it with,” said Brown. “Understanding this all as a new class of objects is a much more interesting way of looking at the solar system and it is quite a bit of fun, too.”

More information from Buie’s webpage on the Pluto images.

The paper about the images isn’t posted online yet, but it will be up on this webpage soon.

Source: Conference call.
Additional images and info from NASA