Story highlights A skull-shaped asteroid passed within about 300,000 miles of Earth

Asteroid was discovered October 10

The asteroid is almost 600 meters in diameter, traveling about 20 miles a second

(CNN) It's as if the universe itself was trying to get into the Halloween spirit.

A large space rock resembling a skull narrowly missed Earth shortly after 1 p.m. ET Saturday. NASA says asteroid 2015 TB145 is a "dead" comet that once spewed debris across the solar system. In NASA terminology, that means it has "shed its volatiles" that would produce the visible tail seen on some comets.

It missed Earth by about 300,000 miles (slightly farther away than the moon). The rock, dubbed 2015 TB145, was visible to those with good telescopes.

Gianluca Masi, astrophysicist and curator of science at Planetario di Roma, featured a live stream through the Virtual Telescope Project in order to track the asteroid as it cruised by Earth. "I always like looking at those close approachers," he told CNN. "They (show that) we do live in such dynamic solar system, where collisions play such a big role in shaping planets, Earth included.

"Now we are aware of those brushing visitors and are studying them, but in ancient times they had such strong effects on life and evolution on this planet," he said.