First Movie of Asteroid 2005 YU55's Flyby

By Nancy Atkinson - November 9, 2011 at 2:58 AM UTC | Planetary Science

Here's a short movie of Asteroid 2005 YU55, created from data collected from the 70-meter Deep Space Network antenna at Goldstone, California. The video was generated from six frames, and each of the six frames required 20 minutes of radar data collection. They are the highest-resolution images ever generated by radar of a near-Earth object.

The data is from Nov. 7, 2011 between 19:24 and 21:35 UT (2:24 p.m. and 4:35 p.m. EST). At the time, 2005 YU55 was approximately 860,000 miles (1.38 million kilometers) away from Earth. Resolution is 4 meters per pixel.

"The movie shows the small subset of images obtained at Goldstone on November 7 that have finished processing. By animating a sequence of radar images, we can see more surface detail than is visible otherwise," said radar astronomer Lance Benner, the principal investigator for the 2005 YU55 observations. "The animation reveals a number of puzzling structures on the surface that we don't yet understand. To date, we've seen less than one half of the surface, so we expect more surprises."

The trajectory of asteroid 2005 YU55 is well understood. At the point of closest approach today at 3:28 p.m. PST (6:28 p.m. EST/2328 UTC), it was no closer than 201,700 miles (324,600 kilometers), as measured from the center of Earth. The gravitational influence of the asteroid will have no detectable effect on anything here on Earth, including our planet's tides or tectonic plates. Although 2005 YU55 is in an orbit that regularly brings it to the vicinity of Earth (and Venus and Mars), the 2011 encounter with Earth is the closest this space rock has come for at least the last 200 years.

The last time a space rock as big came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this large will be in 2028.

Emily Lakdawalla at the

Planetary Society Blog has an article

explaining how images are created from radar data.

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com