Even in a peaceful looking scene such as this one of Saturn and its moon Tethys, the Cassini spacecraft reveals clues about how Saturn is ever-changing. Saturn’s northern hemisphere still shows the scars of the huge storm that raged through much of 2011 (see PIA14905). And, day by day, the shadows cast by the rings on the planet’s southern hemisphere are growing wider as the seasons progress toward northern summer. See PIA11667 and PIA09793 to learn about the changing seasons and the shadows cast by the rings.
Tethys (660 miles, or 1,062 kilometers across) appears above the rings to the left of the center of the image.
The image was taken with the Cassini spacecraft wide-angle camera on Jan. 10, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 39 degrees. Image scale on Saturn is 84 miles (136 kilometers) per pixel.
Image Credit: NASA/JPL-Caltech/Space Science Institute
This image, made from data obtained by NASA’s Dawn spacecraft, shows the mineral distribution in the southern hemisphere of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/INAF/MPS/DLR/IDA › Full image and caption› Image gallery
PASADENA, Calif. – NASA’s Dawn spacecraft has provided researchers with the first orbital analysis of the giant asteroid Vesta, yielding new insights into its creation and kinship with terrestrial planets and Earth’s moon.
Vesta now has been revealed as a special fossil of the early solar system with a more varied, diverse surface than originally thought. Scientists have confirmed a variety of ways in which Vesta more closely resembles a small planet or Earth’s moon than another asteroid. Results appear in today’s edition of the journal Science.
“Dawn’s visit to Vesta has confirmed our broad theories of this giant asteroid’s history, while helping to fill in details it would have been impossible to know from afar,” said Carol Raymond, deputy principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Dawn’s residence at Vesta of nearly a year has made the asteroid’s planet-like qualities obvious and shown us our connection to that bright orb in our night sky.”
Scientists now see Vesta as a layered, planetary building block with an iron core – the only one known to survive the earliest days of the solar system. The asteroid’s geologic complexity can be attributed to a process that separated the asteroid into a crust, mantle and iron core with a radius of approximately 68 miles (110 kilometers) about 4.56 billion years ago. The terrestrial planets and Earth’s moon formed in a similar way.
This artistically modified image of the local galaxy Arp 220, captured by the Hubble Space Telescope, helps illustrate the Herschel results. Image credit: NASA/JPL-Caltech › Full image and caption
PASADENA, Calif. — The Herschel Space Observatory has shown galaxies with the most powerful, active black holes at their cores produce fewer stars than galaxies with less active black holes. The results are the first to demonstrate black holes suppressed galactic star formation when the universe was less than half its current age. Herschel is a European Space Agency-led mission with important NASA contributions.
“We want to know how star formation and black hole activity are linked,” said Mathew Page of University College London’s Mullard Space Science Laboratory in the United Kingdom and lead author of a paper describing these findings in this week’s journal Nature. “The two processes increase together up to a point, but the most energetic black holes appear to turn off star formation.”
Supermassive black holes, weighing as much as millions of suns, are believed to reside in the hearts of all large galaxies. When gas falls upon these monsters, the material is accelerated and heated around the black hole, releasing great torrents of energy. Earlier in the history of the universe, these giant, luminous black holes, called active galactic nuclei, were often much brighter and more energetic. Star formation was also livelier back then.
Studies of nearby galaxies suggest active black holes can squash star formation. The revved-up, central black holes likely heat up and disperse the galactic reservoirs of cold gas needed to create new stars. These studies have only provided “snapshots” in time, however, leaving the overall relationship of active galactic nuclei and star formation unclear, especially over the cosmic history of galaxy formation.
PASADENA, Calif. — NASA’s Mars Reconnaissance Orbiter has revealed that movement in sand dune fields on the Red Planet occurs on a surprisingly large scale, about the same as in dune fields on Earth.
This is unexpected because Mars has a much thinner atmosphere than Earth, is only about one percent as dense, and its high-speed winds are less frequent and weaker than Earth’s.
For years, researchers debated whether sand dunes observed on Mars were mostly fossil features related to past climate, rather than currently active. In the past two years, researchers using images from Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera have detected and reported sand movement.
WASHINGTON — Astronomers are actively hunting a class of supermassive black holes throughout the universe called blazars thanks to data collected by NASA’s Wide-field Infrared Survey Explorer (WISE). The mission has revealed more than 200 blazars and has the potential to find thousands more.Blazars are among the most energetic objects in the universe. They consist of supermassive black holes actively “feeding,” or pulling matter onto them, at the cores of giant galaxies. As the matter is dragged toward the supermassive hole, some of the energy is released in the form of jets traveling at nearly the speed of light. Blazars are unique because their jets are pointed directly at us.
“Blazars are extremely rare because it’s not too often that a supermassive black hole’s jet happens to point towards Earth,” said Franceso Massaro of the Kavli Institute for Particle Astrophysics and Cosmology near Palo Alto, Calif., and principal investigator of the research, published in a series of papers in the Astrophysical Journal. “We came up with a crazy idea to use WISE’s infrared observations, which are typically associated with lower-energy phenomena, to spot high-energy blazars, and it worked better than we hoped.”
The findings ultimately will help researchers understand the extreme physics behind super-fast jets and the evolution of supermassive black holes in the early universe.
Baby stars are creating chaos 1,500 light-years away in the cosmic cloud of the Orion Nebula. Four massive stars make up the bright yellow area in the center of this false-color image for NASA’s Spitzer Space Telescope. Green indicates hydrogen and sulfur gas in the nebula, which is a cocoon of gas and dust. Red and orange indicate carbon-rich molecules. Infant stars appear as yellow dots embedded in the nebula.
A new X-ray study of the remains of an exploded star indicates that the supernova that disrupted the massive star may have turned it inside out in the process. Using very long observations of Cassiopeia A (or Cas A), a team of scientists has mapped the distribution of elements in the supernova remnant in unprecedented detail. This information shows where the different layers of the pre-supernova star are located three hundred years after the explosion, and provides insight into the nature of the supernova.
An artist’s illustration on the left shows a simplified picture of the inner layers of the star that formed Cas A just before it exploded, with the predominant concentrations of different elements represented by different colors: iron in the core (blue), overlaid by sulfur and silicon (green), then magnesium, neon and oxygen (red). The image from NASA’s Chandra X-ray Observatory on the right uses the same color scheme to show the distribution of iron, sulfur and magnesium in the supernova remnant. The data show that the distributions of sulfur and silicon are similar, as are the distributions of magnesium and neon. Oxygen, which according to theoretical models is the most abundant element in the remnant, is difficult to detect because the X-ray emission characteristic of oxygen ions is strongly absorbed by gas in along the line of sight to Cas A, and because almost all the oxygen ions have had all their electrons stripped away.
These results appeared in the February 20th issue of The Astrophysical Journal in a paper by Una Hwang of Goddard Space Flight Center and Johns Hopkins University, and (John) Martin Laming of the Naval Research Laboratory.
Credits: Illustration: NASA/CXC/M.Weiss; Image: NASA/CXC/GSFC/U. Hwang & J. Laming
The NASA/ESA Hubble Space Telescope has spotted the “UFO Galaxy.” NGC 2683 is a spiral galaxy seen almost edge-on, giving it the shape of a classic science fiction spaceship. This is why the astronomers at the Astronaut Memorial Planetarium and Observatory, Cocoa, Fla., gave it this attention-grabbing nickname.
While a bird’s eye view lets us see the detailed structure of a galaxy (such as this Hubble image of a barred spiral), a side-on view has its own perks. In particular, it gives astronomers a great opportunity to see the delicate dusty lanes of the spiral arms silhouetted against the golden haze of the galaxy’s core. In addition, brilliant clusters of young blue stars shine scattered throughout the disc, mapping the galaxy’s star-forming regions.
Perhaps surprisingly, side-on views of galaxies like this one do not prevent astronomers from deducing their structures. Studies of the properties of the light coming from NGC 2683 suggest that this is a barred spiral galaxy, even though the angle we see it at does not let us see this directly.
This image is produced from two adjacent fields observed in visible and infrared light by Hubble’s Advanced Camera for Surveys. A narrow strip which appears slightly blurred and crosses most the image horizontally is a result of a gap between Hubble’s detectors. This strip has been patched using images from observations of the galaxy made by ground-based telescopes, which show significantly less detail. The field of view is approximately 6.5 by 3.3 arcminutes.
A new music video by Beatles tribute band Love & Mersey celebrates the return of ATV to the International Space Station and sends a rocking musical greeting to ESA Astronaut André Kuipers, Russian cosmonaut Oleg Kononenko and the Station’s entire crew.
After a spectacular night-time liftoff from Kourou on 23 March, ESA’s third Automated Transfer vehicle, Edoardo Amaldi, is set for docking with the International Space Station on Wednesday.
In space, André Kuipers and Oleg Kononenko will keep close watch on the docking, ensuring everything goes as planned.
On Earth, another team will be following the mission closely: Dutch group Love & Mersey is one of Europe’s top Beatles tribute bands and they’ve recorded a lively musical video, Back at the ISS.
Inspired by The Beatles, and celebrating the key roles played by André and Oleg in ATV docking, the new video is an energetic greeting to the Station crew and is sung with English, Dutch and Russian lyrics.
“Thank you, Love and Mersey. Back at the ISS is a wonderful gift to music lovers everywhere, and I hope that it inspires young people to follow studies that take them into space one day, too,” said André Kuipers after watching it on the Station.
Preview release via social media
The video was first released via ESA’s YouTube and social media channels on Friday after ATV liftoff. It was also released on the band’s website, and has since been viewed several thousand times.
André on station
“We wanted to do a song that celebrates André, who is Dutch and on his second space mission, and Oleg, who is Russian and will work closely with André during ATV docking,” said band member Jan Hovers.
“ATV is a wonderful bit of European space success, and this will be its third mission to the ISS, so we wrote a song themed on ‘getting back to the ISS’ and made sure we included lyrics in several languages.”
Inspired by cooperation
“We were approached by ESA’s social media team earlier this year, and they asked us if we could sing something in three languages for André and Oleg on the occasion of ATV docking,” says lead singer Marcel van der Linden.
Love & Mersey
“It took a lot of work, but we were really inspired by the incredible partnerships we see today between Europeans, Americans, Russians and others in space.”
The video for Back at the ISS was shot on site at SpaceExpo, collocated with ESTEC, ESA’s technical centre, in Noordwijk, the Netherlands.
It also includes ESA and NASA footage of André’s current 6-month mission as part of ISS Expeditions 30 and 31, historical space footage from the 1960s and the band’s own video clips.
This self portrait from NASA’s Mars Exploration Rover Opportunity shows dust accumulation on the rover’s solar panels as the mission approached its fifth Martian winter. The dust reduces the rover’s power supply, and the rover’s mobility is limited until the winter is over or wind cleans the panels.
This is a mosaic of images taken by Opportunity’s panoramic camera (Pancam) during the 2,111th to 2,814th Martian days, or sols, of the rover’s mission (Dec. 21 to Dec. 24, 2011). The downward-looking view omits the mast on which the camera is mounted.
The portrait is presented in approximate true color, the camera team’s best estimate of what the scene would look like if humans were there and able to see it with their own eyes.
Opportunity has worked through four Martian southern hemisphere winters since it landed in in January 2004 about 14 miles (23 kilometers) northwest of its current location. Closer to the equator than its twin rover, Spirit, Opportunity has not needed to stay on a sun-facing slope during the previous winters. Now, however, Opportunity’s solar panels carry a thicker coating of dust, and the team is using a strategy employed for three winters with Spirit: staying on a sun-facing slope. The sun will pass relatively low in the northern sky from the rover’s perspective for several months of shortened daylight before and after the southern Mars winter solstice on March 30, 2012. Opportunity is conducting research while located on the north-facing slope of a site called “Greeley Haven.”
Image Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.
