SCIENCE LAB SCENICS : QUASI-MOON'S JOURNEY'

ON a cosmic highway - following the Earth on its orbit around the sun : The Earth stands alone in the solar system as a habitable world, as far as we know.

But that doesn't mean we don't get visitors, most often in the form of [ usually harmless ] asteroids. Some even choose to stick around for a while, gaining a moonlike status.

The latest sojourning object is an asteroid that astronomers are calling 2025 PN7. Spotted this summer, it has an orbit that's similar to Earth's own trajectory around the sun, meaning it's like a car traveling in the same highway lane as our planet.

It's what's known as a quasi-moon. And of the handful of known quasi-moons, this one could be the smallest, perhaps no longer than 52 feet [ about 16 meters ].

Some asteroids near Earth come from the main asteroid belt orbiting the sun between Mars and Jupiter.  Others are chunks of the moon that have been ejected after a major meteorite impact.

Scientists have few telescopic observations of 2025 PN7, so there are no real hints about its origins, only speculations,'' said Carlos de la Fuente Marcos, an astronomer in Madrid and an author of a study about its discovery.

Earth has a number of mini-moons and quasi-moons. Mini-moons are objects that orbit our planet. But they tend to swing around Earth for only a matter of months. Unlike mini-moons, quasi-moons orbit the sun, not Earth.

Scientists spotted 2025 PN7 on Aug 2, with the Pan-Starrs observatory at the University of Hawaii. It apparently shifted into its quasi-moon orbit in 1957, in time to see the launching of Sputnik 1, Earth's first artificial satellite Simulations show that it will leave the earth's orbit in 2083.

The World Students Society thanks Robin George Andrews.