'Curious Marie' Meteorite Reveals Rare Element of Early Solar System

© Photo : University of ChicagoThis close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found
This close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found - Sputnik International
Subscribe
Scientists studying a meteorite from the early solar system have announced the natural occurrence of a rare element called curium, which was first produced artificially in 1944.

Dmitri Mendeleev in 1897 - Sputnik International
Russia
In His Element: Top Ten Facts About Periodic Table Creator Dmitri Mendeleev
Part of a meteorite from the early solar system has been found to contain curium, a rare element that until the discovery had only been manufactured in laboratories or the byproduct of nuclear explosions, scientists from the University of Chicago reported on Friday.

"Curium is an elusive element. It is one of the heaviest-known elements, yet it does not occur naturally because all of its isotopes are radioactive and decay rapidly on a geological time scale," said Francois Tissot, lead author of the study, published in Science Advances.

Tissot and his colleagues found evidence of curium in "Curious Marie," an unusual ceramic-like rock that was found embedded in a carbonaceous (carbon-rich) meteorite. 

The rock is a refractory inclusion, which are the oldest objects known to have formed in the 4.5 billion year old solar system. The discovery proves that the element was present during the formation of the solar system.

© Photo : University of ChicagoThis close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found
This close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found   - Sputnik International
This close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found
Curium was discovered in 1944 by a team of chemists led by Glenn Seaborg, who bombarded atoms of plutonium with alpha particles that had been accelerated in a device called a cyclotron. This synthesized the very unstable curium-242, which has a half-life of only 162 days.

The most stable isotope of curium, curium-247, has a half-life of about 15.6 million years and decays into an isotope of uranium (U-235). 

Early studies in the 1980s found large excesses of U-235 in any meteoritic inclusions they analyzed, and concluded that curium was very abundant when the solar system formed.

A mineral or rock formed in the early solar system would be expected to contain more Cm-247 than a similar mineral or rock that formed later, after Cm-247 had decayed. If two such hypothetical minerals were compared today, scientists would find more U-235, the decay product of Cm-247, in the older mineral.

"The idea is simple enough, yet, for nearly 35 years, scientists have argued about the presence of Cm-247 in the early solar system," Tissot said.

periodic table - Sputnik International
Japanese Researchers Likely to Claim 113th Chemical Element Discovery
The team used "Curious Marie" to calculate that the amount of curium present in the early solar system and compared it to other heavy radioactive elements such as iodine-129 and plutonium-244. They found that all these isotopes could have been produced together by a single process in stars.

"This is particularly important because it indicates that as successive generations of stars die and eject the elements they produced into the galaxy, the heaviest elements are produced together, while previous work had suggested that this was not the case," explained Professor Nicolas Dauphas, a coauthor of the paper.

Newsfeed
0
To participate in the discussion
log in or register
loader
Chats
Заголовок открываемого материала