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.

This simulated view from NASA’s Cassini spacecraft shows the expected positions of Saturn and Earth on July 19, 2013, around the time Cassini will take Earth’s picture. Cassini will be about 898 million miles (1.44 billion kilometers) away from Earth at the time. That distance is nearly 10 times the distance from the sun to Earth. Image credit: NASA/JPL-Caltech

PASADENA, Calif. – NASA’s Cassini spacecraft, now exploring Saturn, will take a picture of our home planet from a distance of hundreds of millions of miles on July 19. NASA is inviting the public to help acknowledge the historic interplanetary portrait as it is being taken.

Earth will appear as a small, pale blue dot between the rings of Saturn in the image, which will be part of a mosaic, or multi-image portrait, of the Saturn system Cassini is composing.

“While Earth will be only about a pixel in size from Cassini’s vantage point 898 million [1.44 billion kilometers] away, the team is looking forward to giving the world a chance to see what their home looks like from Saturn,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We hope you’ll join us in waving at Saturn from Earth, so we can commemorate this special opportunity.”

Cassini will start obtaining the Earth part of the mosaic at 2:27 p.m. PDT (5:27 p.m. EDT or 21:27 UTC) and end about 15 minutes later, all while Saturn is eclipsing the sun from Cassini’s point of view. The spacecraft’s unique vantage point in Saturn’s shadow will provide a special scientific opportunity to look at the planet’s rings. At the time of the photo, North America and part of the Atlantic Ocean will be in sunlight.

via NASA – Cassini Probe to Take Photo of Earth From Deep Space.

“David Fuller has been a stargazer for over 30 years, fascinated by the space programs of all countries and the wonders of what exists in space that can be seen visually and in other wavelengths.  Tired of seeing other amateur astronomers complain about light pollution but not doing anything about it, in 2008 he began writing local newspaper articles that described how anyone can see what’s up in the night sky.  In 2010, after noticing a serious lack of good videos online about how to align an equatorial mount, he took a consumer-grade digital camera and created a simple “how to” video that has become one of the most highly rated videos on the subject.

Sensing an opportunity, some better equipment was purchased and Eyes on the Sky moved from print to video.  In about 12 month’s time, the YouTube channel for Eyes on the Sky went from zero subscribers and views to 300+ subscribers and over 40,000 views.  By the end of 2012, that had leapt to 200+ subscribers and 300,000+ views!  The new format of Eyes on the Sky in 2012 has been well-received, and new opportunities present themselves regularly for reaching more people about the night sky and light pollution reduction.

Dave is actively involved in local astronomy outreach efforts including his local club (Kankakee Area StarGazers in Kankakee IL), the Chicago Astronomer sidewalk astronomy outreach of Joe Guzman and the Will County Forest Preserve District in Illinois.  He is also a member of the Chicago Astronomical Society, and works with several local groups dedicated to light pollution reduction.  In addition to that, Dave offers astronomy presentations to institutions of informal education such as libraries and park districts to help empower people to learn about what they can find and see in the night sky, as well as how to use their optical instruments to maximum effectiveness.”