Oort Cloud tagged posts

Researchers from Western have shown that a fireball that originated at the edge of the solar system was likely made of rock, not ice, challenging long-held beliefs about how the solar system was formed.

Just at the edge of our solar system and halfway to the nearest stars is a collection of icy objects sailing through space, known as the Oort Cloud. Passing stars sometimes nudge these icy travelers towards the sun, and we see them as comets with long tails. Scientists have yet to observe any objects in the Oort Cloud directly, but everything detected so far coming from its direction has been made of ice.

Theoretically, the very basis of understa...

Astronomers calculate that the Oort Cloud may be home to more visiting objects than objects that belong to our solar system. In 2019, astronomers spotted something incredible in our backyard: a rogue comet from another star system. Named Borisov, the icy snowball traveled 110,000 miles per hour and marked the first and only interstellar comet ever detected by humans.

But what if these interstellar visitors — comets, meteors, asteroids and other debris from beyond our solar system — are more common than we think?

In a new study published Monday in the Monthly Notices of the Royal Astronomical Society, astronomers Amir Siraj and Avi Loeb at the Center for Astrophysics | Harvard & Smithsonian (CfA) present new calculations showing that in the Oort Clou...

A new study suggests that distant “long-period” comets — which take more than 200 years to orbit the sun — are more common than previously thought. This illustration shows how the researchers used data from NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft to determine the nucleus sizes of several of these distant comets. They subtracted a model of how dust and gas behave in comets in order to obtain the core size. Credit: NASA/JPL-Caltech

Comets that take more than 200 years to make one revolution around the sun are notoriously difficult to study. Because they spend most of their time far from our area of the solar system, many “long-period comets” will never approach the sun in a person’s lifetime...

An enhanced image of Comet ISON taken by the Hubble Space Telescope in May 2013. Credit: NASA

Comet ISON, a bright ball of frozen matter from the earliest days of the universe, was inbound from the Oort Cloud at the edge of the solar system and expected to pierce the Sun’s corona on Nov. 28. Scientists were expecting quite a show. But instead of a brilliant cosmic display, there was … nothing. “The first thing we did was make sure that we had definitely seen nothing,” said Paul Bryans, NCAR, who was looking for the comet using NASA’s Solar Dynamics Observatory. “We did image processing just to make sure nothing was there, and it wasn’t. But that’s not necessarily a boring result. That can tell us something.”

“We think that the most likely thing that happened is that Comet ISON broke up b...