How many rings do you see in this new image of the galaxy Messier 94, also known as NGC 4736? While at first glance one might see a number of them, astronomers believe there is just one. This image was captured in infrared light by NASA’s Spitzer Space Telescope. Image credit: NASA/JPL-Caltech › Full image and caption

Johnny Cash may have preferred this galaxy’s burning ring of fire to the one he sang about falling into in his popular song. The “starburst ring” seen at center in red and yellow hues is not the product of love, as in the song, but is instead a frenetic region of star formation.

The galaxy, a spiral beauty called Messier 94, is located about 17 million light-years away. In this image from NASA’s Spitzer Space Telescope, infrared light is represented in different colors, with blue having the shortest wavelengths and red, the longest.

Starburst rings like this can often be triggered by gravitational encounters with other galaxies but, in this case, may have instead been caused by the galaxy’s oval shape. Gas in the ring is being converted into hot, young stars, which then warm the dust, causing it to glow with infrared light.

The outer, faint blue ring around the galaxy might be an optical illusion. Astronomers think that two separate spiral arms appear as a single unbroken ring when viewed from our position in space.

via NASA – Galaxy’s Ring of Fire.

City skies (right) are often significantly dimmed by sky glow. Credit: Jeremy Stanley

Step out into the darkness a few hours after sunset. What do you see overhead? If you live in a relatively unpopulated part of the world, you might see the broad stripe of the Milky Way splashed against a backdrop of black sky punctuated by countless stars. If, on the other hand, you live in a teeming metropolis, what’s visible might have much more to do with where you find yourself on the planet than where we find ourselves in the galaxy.

Artificial illumination has dramatically changed the night sky across the globe. And considering that more than half of people worldwide live in urban areas—and more than one fifth live in large cities of one million or more inhabitants—light pollution obscures the stars above billions of people.

Since 2006 a project called GLOBE at Night has been quantifying light pollution using the very people it affects as measuring instruments. The project enlists citizen scientists to make naked-eye observations of a given constellation, then compare what they see with a series of star charts calibrated for different levels of light pollution. Participants submit their observations via an online form. The GLOBE at Night’s most recent campaign, for 2012, gathered nearly 17,000 observations from participants in 92 countries. (The 2013 campaign is still accepting data for a few more weeks.)

via Citizen Scientists Track Light Pollution as Humanity Loses Touch with the Night Sky | Observations, Scientific American Blog Network.

Credit: NASA’s Goddard Space Flight Center

NASA’s first mission to sample an asteroid is moving ahead into development and testing in preparation for its launch in 2016.

The Origins-Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) passed a confirmation review Wednesday called Key Decision Point (KDP)-C. NASA officials reviewed a series of detailed project assessments and authorized the spacecraft’s continuation into the development phase.

OSIRIS-REx will rendezvous with the asteroid Bennu in 2018 and return a sample of it to Earth in 2023.

“Successfully passing KDP-C is a major milestone for the project,” said Mike Donnelly, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Md. “This means NASA believes we have an executable plan to return a sample from Bennu. It now falls on the project and its development team members to execute that plan.”

Bennu could hold clues to the origin of the solar system. OSIRIS-REx will map the asteroid’s global properties, measure non-gravitational forces and provide observations that can be compared with data obtained by telescope observations from Earth. OSIRIS-REx will collect a minimum of 2 ounces (60 grams) of surface material.

via NASA – NASA’s Asteroid Sample Return Mission Moves into Development.