Right now we can’t observe extrasolar Oort clouds, if they exist. (Not for lack of trying; we’ve been looking for them since 1991!) In fact, we can’t even directly observe our own Oort Cloud. We can ...

The human mind may find it difficult to conceptualize: a cosmic cloud so colossal it surrounds the Sun and eight planets as it extends trillions of miles into deep space. The spherical shell known as ...

Forget what you learned in school. The solar system isn't just a flat disc of planets it's a 3D bubble moving through space.

In the farthest reaches of our solar system, beyond the familiar planets and even the icy Kuiper Belt, lies a mysterious ...

The Oort Cloud, an expanse of icy bodies in the far reaches of our solar system, is shown here in a scene from "Encounters in the Milky Way," a show at New York City's Hayden Planetarium that spawned ...

The human mind may find it difficult to conceptualize a cosmic cloud so colossal it surrounds the Sun and eight planets as it extends trillions of miles into deep space. The spherical shell known as ...

Humans generally like stability. We are used to our small, predictable world: Every 24 hours, we rotate on our axis; every 365 days, we revolve around the Sun. We have followed this pattern for ...

Discover the secrets of the Oort Cloud: astronomers unveil a comet from the inner Oort Cloud with hints about solar system formation. Astronomers have spotted an icy object near Neptune that they say ...

The Oort cloud is a region in our solar system's vicinity we don’t know all that much about. Named after Dutch astronomer Jan Oort, it is a theoretical concept comprising planetesimals (solid objects ...

Like the newly-identified 2014 UN271, the NEOWISE comet pictured here is a long-period comet originating in the Oort Cloud. Photo by NASA Johnson via Flickr under CC BY-NC-ND 2.0 Amateur astronomers, ...

A new kind of comet that is nearly tailless has been discovered — and the surprises don't stop there. The new comet recently returned from the edge of the solar system but may have originated much ...

Ernest Opik, an Estonian astronomer based at the Astronomical Observatory in Tartu from 1921-1944, commenced research on the frequencies and speeds of meteors and comets in the 1920s. In 1932, Opik ...