‘City killer’ asteroids could be lurking in a hidden area of the solar system
Astronomer Scott Sheppard wrote an article on Perspective titled “In the shine of the sun” in the review Science.
Sheppard is an astronomer at the University of Hawaii’s Institute of Astronomy and believes scientists need to look closer for near-Earth objects (NEOs) in space toward the Sun. He notes that most observations are often taken from the night sky, but near-Earth objects like asteroids that pose a potential threat to Earth could lurk between the Sun and Earth, some of which have been discovered recently.
One such near-Earth asteroid (NEA) has been found inside the orbit of Venus, and another has been discovered with the shortest known orbital period around the Sun. The night sky is studied more frequently because sunlight does not overwhelm the observations. However, Sheppard notes that the technology now exists to monitor the sky in the direction of the Sun during twilight hours.
There “twilight telescope“Polls that Sheppard and others may conduct in the future will help find”city killers,” NEOs at least 460 feet (140 meters) in diameter. Current models indicate that about 90% of “planet killer“NEOs have been found; however, only about half of the city’s killers have been found.
“The main reason we haven’t found all of the “city killers” is simply because we haven’t watched the sky at the same depth for years and years to find them.“, Sheppard said Space.com.
“We’re doing a full survey looking for anything that moves around the orbit of Venus, a place that we haven’t really studied very deeply in the past with anything other than small one-meter telescopes. It’s quite difficult to do and usually the bigger telescopes don’t have a very large field of view so you can’t cover a lot of sky“, Shepard said.
You can read Sheppard’s article here.