A sharp new view of the Antennae galaxies allows astronomers to see the action happening at the heart of the colliding pair. The picture combines several wavelengths of visible light captured by the European Southern Observatory's Very Large Telescope in Chile.
The cores of the two galaxies (pale yellow) are surrounded by glowing hydrogen gas (pink) and bursts of newborn stars (blue) triggered by the massive merger.
Earlier this week ESO released the first picture from its ALMA telescope, a shot of the Antennae taken in millimeter wavelengths, which revealed cold clouds of star-forming gas invisible to optical-light telescopes.
Image courtesy A. Milani, ESO
A sky crane lowers the Mars rover Curiosity to the red planet's surface in a newly released artist's illustration of how the SUV-size robot is slated to land.
The new rover is due to launch this fall and arrive at Mars's Gale Crater in August 2012. Being five times heavier than its predecessors-the rovers Spirit and Opportunity-Curiosity can't fall safely to the surface cushioned by airbags.
Instead NASA designed the sky crane, which will attach to the top of the rover and help slow its descent via engines. The sky crane will then suspend the rover on tethers, detach upon touchdown, and fly away, falling hundreds of meters from the landing site.
Illustration courtesy Caltech/NASA
As-yet unknown minerals give the central peak of an unnamed Martian crater an iridescent sheen in a new colorized picture from NASA's HiRISE camera.
When impact craters surpass a certain size, gravity causes their sloping inner walls to collapse, creating a central peak of material that can contain ancient material from deep under the surface.
The colorful rocks exposed in this crater's central peak probably hold minerals made by the presence of liquid water on early Mars, according to NASA.
Image courtesy U. Arizona/NASA
Last week NASA's Solar Dynamics Observatory spotted a midsize flare that shot a plume of plasma (charged gas) from the sun. Most of the material fell back onto the active region that had spawned the flare.
Shortly afterward, the sun rotated so that the same active region faced Earth, and several subsequent flares were linked to eruptions of charged particles hurled toward our planet that sparked geomagnetic storms.
Resembling a video-game screenshot, this view of the young star HR 8799 was captured by the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer in 1998. Now, a reanalysis of the data has confirmed the presence of three of the planets known to orbit the star.
The planets had been hidden in the Hubble data because light from the star initially blocked them from view. Near-infrared ground-based images later uncovered four giant worlds around the star.
One of these planets was dug up in the Hubble data in 2009 by digitally subtracting starlight, and astronomers have now used the same technique to find the other three.
The picture was made using data from the craft's X-ray Spectrometer (XRS), which measures surface fluorescence generated when solar x-rays hit the planet. The white circle in the frame above indicates the region XRS could see following a solar flare on June 16.
Fluorescence can indicate the types of rocks present and thus offer clues to their origins. In this picture, green-colored plains were likely made by volcanism, while blue plains were made when rock was melted by impacts. Yellow marks plains of uncertain origin.
Image courtesy JHUAPL/CIW/NASA
South in Shadow
Saturn's thin rings cast ever wider shadows on the planet's southern hemisphere as the seasons progress on the gas giant, seen in a new picture from NASA's Cassini orbiter.
Saturn was at equinox in August 2009, when the sun was shining edge-on to the planet's equator. The rings appeared almost invisible to astronomers on Earth, but from orbit Cassini was able to see previously unknown structures in the rings highlighted by the unusual equinox shadows.
Saturn is now heading toward its summer solstice, which will happen in May 2017.
Image courtesy SSI/Caltech/NASA
Cluster of Youth
Thousands of stars glitter in the globular cluster M53, seen in sharp detail in a new Hubble Space Telescope picture. Such spherical star bundles are tightly bound by gravity, getting denser near their cores.
Astronomers think the stars in globular clusters all formed around the same time, and that most should be old, red stars. But M53 is among the clusters to house so-called blue stragglers, much younger stars that somehow buck this trend.
(See "'Blue Straggler' Stars Cannibalize to Stay Young.")