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.

A diagram of the Kepler space telescope. Credit: NASA

NASA’s Kepler telescope has lost its ability to precisely point toward stars, putting its exoplanet search in jeopardy. One of the reaction wheels –devices which enable the spacecraft to aim in different directions without firing thrusters – has failed. This is of grave concern because last year reaction wheel #2 failed, and now #4 has failed. Kepler scientists say the spacecraft needs at least three reaction wheels to be able to point precisely enough to hunt for planets orbiting distant stars.

“We need three wheels in service to give us the pointing precision to enable us to find planets,” said Bill Borucki, Kepler principal investigator, during a press briefing today. “Without three wheels it is unclear whether we could continue to do anything on that order.”

But the Kepler team said there are still possibilities of keeping the spacecraft in working order, or perhaps even finding other opportunities for different science for Kepler, something that doesn’t require such precise pointing abilities.

via .Universe Today-Kepler Planet-Hunting Mission in Jeopardy.