Scientists found an asteroid that is closer to the sun than others

Image courtesy of  2021 Elena11/Shutterstock. 

 Joel Kontinen

 

No asteroid has even been discovered this close to the sun. However, now astronomers have found an asteroid that gets to within 20 million kilometres of it. 

They have also found two asteroids as part of a hunt for rocks that are closer to the sun than Earth and may sometime hit the Earth

Source:

Crane, Leah. 2022. Astronomers found a weird asteroid closer to the sun than any other. New Scientist 5 October. 

Toy car in ”ancient” rock

Joel Kontinen

Most people assume that it takes millions of years to form rocks. However, a small rock found near Brisbane, Australia, contained a toy car. In other words, it could not be much older than ten years or so, as Dr. Tas Walker explains in this brief video clip:

The Oldest Rocks in the World?

The Helvetinkolu Gorge in southern Finland. Estimates for the age of these rocks vary by a factor of over ten, from 150 million to 1.9 billion years.

Joel Kontinen

A group of geologists claims they have found the oldest rocks in the world. In a paper published in the journal Science they say that a piece of Nuvvuangittuq greenstone is 250 million years older than any known rock.

Samples taken from the rock were sent to the Carnegie Institute in Washington for a chemical analysis. The rocks were dated by the samarium-neodymium method. The age of the rocks ranged from 3. 8 to 4.28 billion years.

Don Francis, a professor of geology at the McGill University in Montreal, thinks 4.28 billion years is the most likely date.

The rock also contains ”a chemical signature” that may be evidence of life.

People often suppose that radiometric dating methods are reliable but they almost regularly give incongruous results. Radiometric methods do not measure age but the amount of certain isotopes. Researchers can never be absolutely sure of the original amounts of the isotopes and they also have to make several other assumptions. Thus, they have often had to re-date fossils, rocks and even caves.

In addition, the discovery of soft tissues in T. rex bones and of carbon-14 in diamonds weakens the belief in millions of years. Comets , Mercury’s magnetic field and Saturn's moon Titan also speak for a young solar system.

The belief in millions of years can be a very ideological issue especially for non-theists. The idea of an old earth is actually an assumption that saw daylight before the discovery of the earliest dating methods.




Source:

Morgan, James. 2008. Team finds Earth's 'oldest rocks' . BBC News. (26 September)
http://news.bbc.co.uk/2/hi/science/nature/7639024.stm