Surrounding Earth is a dynamic region called the magnetosphere. The region is governed by magnetic and electric forces, incoming energy and material from the sun, and a vast zoo of waves and processes unlike what is normally experienced in Earth-bound physics. Nestled inside this constantly changing magnetic bubble lies a donut of charged particles generally aligned with Earth’s equator. Known as the ring current, its waxing and waning is a crucial part of the space weather surrounding our planet, able to induce magnetic fluctuations on the ground as well as to transmit disruptive surface charges onto spacecraft.

On June 15, 2008, a new set of instruments began stereoscopic imaging of this mysterious region. Called Two Wide-angle Imaging Neutral-atom Spectrometers or TWINS, these satellites orbit in widely separated planes to provide the first and only stereo view of the ring current. TWINS maps the energetic neutral atoms that shoot away from the ring current when created by ion collisions.

In five years of operation, the TWINS maps have provided three-dimensional images and global characterization of this region. The observatories track how the magnetosphere responds to space weather storms, characterize global information such as temperature and shape of various structures within the magnetosphere, and improve models of the magnetosphere that can be used to simulate a vast array of events.

“With two satellites, with two sets of simultaneous images we can see things that are entirely new,” said Mei-Ching Fok, the project scientist for TWINS at NASA’s Goddard Space Flight Center in Greenbelt, Md. “This is the first ever stereoscopic energetic neutral atom mission, and it’s changed the way we understand the ring current.”

via NASA – Five Years of Stereo Imaging for NASA’s TWINS.

Credit:NASA

NASA Releases a 1.3 Billion Pixel mosaic of the martian landscape. this monstrous mosaic is made from almost 900 images taken with some of Curiosity’s 17 cameras during  its visit to Gail Crater.  Click on the picture above and take a high-resolution tour of  the Mars surface.

An asteroid passed Earth last week, and with the Arecibo radio telescope astronomers got an unprecedented look—along with a couple surprises.

Asteroid 1998 QE2 came within six million kilometers of Earth, about 15 times the distance to the Moon. Researchers used Arecibo’s 300-meter-wide dish to bounce radio signals off the rock. By measuring how quickly the transmitted signals returned, the researchers could map the asteroid’s surface.

The first images, however, came back with a twist: the asteroid has a moon. At one quarter the size of the three-kilometer-diameter asteroid, the moonlet has the same proportional size to 1998 QE2 as our moon does to Earth. The discovery is a pleasant bonus: astronomers can calculate the asteroid’s mass by measuring how quickly the satellite orbits it.

Spectra obtained at NASA’s Infrared Telescope Facility in Hawaii also revealed that the asteroid’s surface has not been significantly altered from its original composition. That makes 1998 QE2 unique among all known asteroids and collected meteorites. So-called “primitive” asteroids can reveal details about the origin and evolution of the solar system.

via Arecibo Telescope Gets Detailed Look at Passing Asteroid: Scientific American Gallery.