Tonight, we finally get a chance to see Earth-approaching asteroid 2014 JO25 canter across the sky a day hours after its closest approach to Earth. You’ll need a 3 or 4-inch telescope to find and track it, and I hope you do. Unfortunately, my skies will be cloudy, so if you see this giant hurtling rock, please send a description using the comments link below.
Radar images of asteroid were made early this morning with NASA’s 230-foot (70-meter) radio antenna at Goldstone Deep Space Communications Complex in California. They reveal a peanut-shaped asteroid that rotates about once every 5 hours and show details as small as 25 feet. The larger of the two lobes is about 2,000 feet (620 meters) across. Since that was the original size estimate for the entire asteroid, that means 2014 JO25 is bigger than we thought.
Near-Earth Asteroid 2014 JO25 — Orbit & first images animation
Today’s encounter is the closest the object has come to the Earth in 400 years and will be its closest approach for at least the next 500 years.
“The asteroid has a contact binary structure — two lobes connected by a neck-like region,” said Shantanu Naidu, a scientist from NASA’s Jet Propulsion Laboratory in Pasadena, California, who led the Goldstone observations. “The images show flat facets, concavities and angular topography.”
Tom Ruen created this fab animation of the asteroid’s flyby of Earth as seen from the asteroid’s perspective
Radar observations of the asteroid have also been underway at the National Science Foundation’s Arecibo Observatory in Puerto Rico with more observations coming today through the 21st which may show even finer details. The technique of pinging asteroids with radio waves and eking out information based on the returning echoes has been used to observe hundreds of asteroids. When these relics from the early solar system pass relatively close to Earth, astronomers can glean their sizes, shapes, rotation, surface features, and roughness, as well as determine their orbits with precision.
In other astro news today, returning sunspot group 2644, located just beyond the sun’s eastern edge (limb) shot off a C5-class solar flare yesterday evening and launched a big, bright coronal mass ejection (CME) into space. Here’s an animation of the event. Although not directed at Earth, it proves the spot group has retained the power to produce flares. Once it rotates to face us, let’s cross our fingers that it will continue to boil away and perhaps fire up some auroras here at home.