The Sunday asteroid, named 2018 RC, is about the size of a jumbo jet, according to NASA's Asteroid Watch team. It was discovered Sept. 3 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Hawaii and will pass within 136,000 miles (220,000 kilometers) of the Earth when it makes its closest approach to Earth on Sunday. That's well inside the average distance between the Earth and the moon. The moon is on average about 238,000 miles (382,900 km) from the Earth. [Gallery: Potentially Dangerous Asteroids]
The Virtual Telescope Project, an online observatory founded by astrophysicist Gianluca Masi of the Bellatrix Astronomical Observatory in Ceccano, Italy, will host a live webcast this evening starting at 6 p.m. EDT (2200 GMT), and you can watch it live here on Space.com, courtesy of the Virtual Telescope Project, or directly at virtualtelescope.eu/webtv.
Asteroid 2018 RC is somewhere between 100 to 230 feet (32 to 71 meters) in diameter - a NASA estimate pegged the space rock's width at 130 feet ( 40 m) - and will appear as a 12th-magnitude speck of light that can be seen with small telescopes (larger than 4 inches, or 10 cm). During tonight's webcast, Masi will use a robotic telescope to easily keep an eye on the asteroid as it traverses a backdrop of stars.
Sunday's 2018 RC asteroid encounter will follow an even closer flyby of the newly discovered asteroid 2018 RW, which was only spotted by astronomers on Friday (Sept. 7), according to NASA. But this asteroid is much smaller, only 10 feet (3 m) across. It's about the size of a car, according to NASA's Asteroid Watch team.