Wide-Field Infrared Survey Explorer (WISE) Image: Southern constellation of Circinus

Credit: NASA/JPL-Caltech/UCLA

The Wide-Field Infrared Survey Explorer (WISE), has uncovered a striking population of young stellar objects in a complex of dense, dark clouds in the southern constellation of Circinus.

This mosaic from WISE covers an area on the sky so large that it could contain a grid of 11 by 7 full moons.

The cloud itself is some 2,280 light-years away and spans more than 180 light-years across.

When an interstellar cloud becomes dense and cool enough, molecules can form in it, so astronomers call these molecular clouds.

Molecular clouds are where stars first form, and astronomers study them hoping to learn about the earliest stages in the lives of stars.

These clouds are so dense that the dust within blocks visible wavelengths of light. Telescopes that see visible light only detect ghostly dark patches in the sky, called dark nebulae.

Constellation of Circinus. Visible in the southern hemisphere and best at mid-evening during June. A small constellation, first defined in the 18th century.

The infrared vision of WISE was able to pierce through the cloud and see the light of the dust itself and newly forming stars within.

The colours used in this image represent specific wavelengths of infrared light.

Blue and cyan represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars.

Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

In the western part of the cloud (right of the image center) there is a prominent cluster of red-colored sources.

This is light coming from large amounts of warm, concentrated dust. These are what astronomers call young stellar objects, stars so new that they have yet to begin nuclear fusion in their cores and are enveloped by cocoons of dust.

These young stars also power large-scale outflows of gas that are detected by radio telescopes. As these young stars develop, they will emerge from their cocoons and begin to light up their surroundings, making the Circinus cloud shine in visible light.

Also in this image: the brightest star in the upper-right is IRAS 14484-6152, a giant star rich in carbon. The red object to the east (left) of the brightest nebulosity is an O-type star.

It derives its red colour from the surrounding dust, which is being heated by this massive star.

IRAS 14568-6304 is one of several outflow sources in the Circinus-West clump. Together, these sources make up one of the brightest, most massive, and most energetic outflows ever reported.

Scientists have even suggested calling Circinus-West the “nest of molecular outflows” in tribute to this activity.

NASA Cassini Image: Saturn's Southern Winter Approaches

Credit: NASA /JPL-Caltech /Space Science Institute

The shadows of Saturn's rings slide farther southward as Saturn approaches southern winter (or northern summer). 

Saturn now lies almost exactly halfway between its equinox (August 2009) and southern winter solstice (in May 2017). 

This view centers on an area at 22 degrees south latitude on Saturn. 

Cassini spacecraft took the image with its wide-angle camera on May 6, 2013.

Tungurahua Volcano Erupting, Ecuador

Volcano Tungurahua sometimes erupts spectacularly.

Pictured above, molten rock so hot it glows visibly pours down the sides of the 5,000-meter high Tungurahua, while a cloud of dark ash is seen being ejected toward the left.

Wispy white clouds flow around the lava-lit peak, while a star-lit sky shines in the distance.

The above image was captured in 2006 as ash fell around the adventurous photographer.

Located in Ecuador, Tungurahua has become active roughly every 90 years since for the last 1,300 years.

Constellation Puppis: The Stern

This ghoulish skull with glowing eyes is actually the area surrounding the stellar cluster NGC 2467, located in the southern constellation of Puppis - "The Stern"

Picture: NASA / Rex Features

False-colour composite image of the glow of Saturn's Southern auroras

Glowing Southern Lights

This false-color composite image, constructed from data obtained by NASA's Cassini spacecraft, shows the glow of auroras streaking out about 1,000 kilometers (600 miles) from the cloud tops of Saturn's south polar region. It is among the first images released from a study that identifies images showing auroral emissions out of the entire catalogue of images taken by Cassini's visual and infrared mapping spectrometer. In this image constructed from data collected in the near-infrared wavelengths of light, the auroral emission is shown in green. The data represents emissions from hydrogen ions in of light between 3 and 4 microns in wavelength. In general, scientists designated blue to indicate sunlight reflected at a wavelength of 2 microns, green to indicate sunlight reflected at 3 microns and red to indicate thermal emission at 5 microns. Saturn's rings reflect sunlight at 2 microns, but not at 3 and 5 microns, so they appear deep blue. Saturn's high altitude haze reflects sunlight at both 2 and 3 microns, but not at 5 microns, and so it appears green to blue-green. The heat emission from the interior of Saturn is only seen at 5 microns wavelength in the spectrometer data, and thus appears red. The dark spots and banded features in the image are clouds and small storms that outline the deeper weather systems and circulation patterns of the planet. They are illuminated from underneath by Saturn's thermal emission, and thus appear in silhouette. The composite image was made from 65 individual observations by Cassini's visual and infrared mapping spectrometer on Nov. 1, 2008. The observations were each six minutes long. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/ . The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona/University of Leicester