50 years ago, scientists had hints of a planet beyond Pluto
Excerpt from the May 6, 1972 issue of Science News
![a photo of the Atacama Cosmology Telescope scanning the night sky with the Milky Way overhead](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2022/05/050722_50ya_feat.jpg?fit=1030%2C580&ssl=1)
Astronomers have used the Atacama Cosmology Telescope in Chile to scan nearly 90 percent of the Southern Hemisphere’s sky in search of Planet Nine.
Jon Ward/University of Pennsylvania