Look up, there is an asteroid as big as the Rock of Gibraltar is about to zip past Earth on April 19 at a relatively safe but dangerously close distance, according to astronomers.
According to NASA: "Although there is no possibility for the asteroid to collide with our planet, this will be a very close approach for an asteroid this size,"
Called 2014-JO25 and approximately 650 meters (2,000 feet) across, it will come within 1.8 million kilometers (1.1 million miles) of Earth. This distance is less than five times the distance to the Moon.
It will pass closest to Earth after having circled around the Sun. 2014-J25's will then stay on path towards Jupiter before heading back toward the center of our Solar System.
The next close encounter with a big rock will not happen before 2027, when the 800-meter (half-mile) wide asteroid 199-AN10 will fly by at just one lunar distance, about 380,000 km (236,000 miles).
The last time 2014-JO25 was in our close neighborhood was 400 years ago, and its next encounter with Earth won't happen until sometime after 2600.
The April 19 flyby is an "outstanding opportunity" for astronomers and amateur stargazers, NASA said.
"Astronomers plan to observe it with telescopes around the world to learn as much about it as possible," the US space agency noted.
Besides its size and trajectory, scientists also know that its surface is twice as reflective as that of the Moon. It should be visible with a small optical telescope for one or two nights before moving out of range.
2014-J25 was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona.
Also on April 19, a comet known as PanSTARRS will make its closest approach to Earth at a "very safe" distance of 175 million km (109 million miles), according to NASA.
The comet has brightened recently and should be visible in the dawn sky with binoculars or a small telescope.
Asteroids are composed of rocky and metallic material, whereas comets — generally smaller — are more typically made of ice, dust, and rocky stuff.
Both were formed early in the history of the solar system some 4.5 billion years ago.