ESO: Unique Fragment from Earth’s Formation Returns

[bystander]

Unique Fragment from Earth’s Formation Returns after Billions of Years in Cold Storage
ESO Science Release | VLT | CFHT | 2016 Apr 29

Tailless Manx comet from Oort Cloud brings clues about the origin of the Solar System

[img3="The Unique Rocky Comet C/2014 S3 (PANSTARRS)
Credit: K. Meech (IfA/UH)/CFHT/ESO"]https://cdn.eso.org/images/screen/eso1614c.jpg[/img3][hr][/hr]

Astronomers have found a unique object that appears to be made of inner Solar System material from the time of Earth’s formation, which has been preserved in the Oort Cloud far from the Sun for billions of years. Observations with ESO’s Very Large Telescope, and the Canada France Hawai`i Telescope, show that C/2014 S3 (PANSTARRS) is the first object to be discovered on a long-period cometary orbit that has the characteristics of a pristine inner Solar System asteroid. It may provide important clues about how the Solar System formed. ...

Their observations indicate that it is an ancient rocky body, rather than a contemporary asteroid that strayed out. As such, it is one of the potential building blocks of the rocky planets, such as the Earth, that was expelled from the inner Solar System and preserved in the deep freeze of the Oort Cloud for billions of years. ...

C/2014 S3 (PANSTARRS) was originally identified by the Pan-STARRS1 telescope as a weakly active comet a little over twice as far from the Sun as the Earth. Its current long orbital period (around 860 years) suggests that its source is in the Oort Cloud, and it was nudged comparatively recently into an orbit that brings it closer to the Sun.

The team immediately noticed that C/2014 S3 (PANSTARRS) was unusual, as it does not have the characteristic tail that most long-period comets have when they approach so close to the Sun. As a result, it has been dubbed a Manx comet, after the tailless cat. Within weeks of its discovery, the team obtained spectra of the very faint object with ESO’s Very Large Telescope in Chile.

Careful study of the light reflected by C/2014 S3 (PANSTARRS) indicates that it is typical of asteroids known as S-type, which are usually found in the inner asteroid main belt. ...

Back from the Deep Freeze: A Piece of the Early Solar System Returns
Institute for Astronomy | University of Hawaii | 2016 Apr 29

Inner Solar System Material Discovered in the Oort Cloud - Karen J. Meech et al

• Science Advances 2(4):e1600038 (29 Apr 2016) DOI: 10.1126/sciadv.1600038 (pdf)

[Ann]

Astronomers find a tailless comet, first of its kind

Click to view full size image

Tailless Manx cat, somewhat similar to tailless Manx comet.
Photo: Tina Kay.

Reuters wrote:
Astronomers have found a first-of-its-kind tailless comet whose composition may offer clues into long-standing questions about the solar system's formation and evolution, according to research published on Friday in the journal Science Advances.

The so-called "Manx" comet, named after a breed of cats without tails, was made of rocky materials that are normally found near Earth. Most comets are made of ice and other frozen compounds and were formed in solar system's frigid far reaches.

Researchers believe the newly found comet was formed in the same region as Earth, then booted to the solar system’s backyard like a gravitational slingshot as planets jostled for position.

Scientists involved in the discovery now seek to learn how many more Manx comets exist, which could help to resolve debate over exactly how and when the solar system settled into its current configuration.

"Depending how many we find, we will know whether the giant planets danced across the solar system when they were young, or if they grew up quietly without moving much," paper co-author Olivier Hainaut, an astronomer with the European Southern Observatory in Germany, said in a statement...