Earth Collects 5 to 300 Tons of Cosmic Dust a Day

Image credit: ESO/Y. Beletsky Currently, estimates of the Earth's intake of space dust vary from around five tons to as much as 300 tons every day. A €2.5 million international project, led by Professor John Plane from the University's School of Chemistry, will seek to address this discrepancy. Scientists at the University of Leeds are looking to discover how dust particles in the solar system interact with the Earth's atmosphere. Currently, estimates of the Earth's intake of space dust vary from around five tons to as much as 300 tons every day. A € 2.5 million international project, led by ERC Advanced grantee John Plane from the University's School of Chemistry, will seek to address this discrepancy. The Cosmic Dust in the Terrestrial Atmosphere (CODITA) project will investigate what happens to the dust from its origin in the outer solar system all the way to the earth's surface. The work, funded by the European Research Council, will also explore whether cosmic dust has a role in the Earth's climate and how it interacts with the ozone layer in the stratosphere. "People tend to think space is completely empty, but if all the dust between the Sun and Jupiter was compressed it would create a moon 16 miles across. It's surprising that we aren't more certain how much of this comes to Earth" said Professor Plane. "If the dust...

Read More........→August 20, 2015

Carbon Glow of Galaxies At 'Cosmic Dawn' Observed

When galaxies first assembled, during a period often referred to as 'Cosmic Dawn,' most of the space between the stars was filled with a mixture of hydrogen and helium produced in the Big Bang. As subsequent generations of massive stars ended their brief but brilliant lives as supernovas, they seeded the interstellar medium with a fine dust of heavy elements, mostly carbon, silicon, and oxygen, which are forged in their nuclear furnaces. Astronomers study the elements scattered between the stars to learn about the internal workings of galaxies, their motion and chemistry. To date, however, attempts to detect the telltale radio signature of carbon in the very early Universe have been thwarted, perhaps -- as some have speculated -- by the need to allow a few billion years more for stars to manufacture sufficient quantities to be observed across such vast cosmic distances. New observations with the Atacama Large Millimeter/submillimeter Array (ALMA), however, readily detected the first faint traces of carbon atoms permeating the interstellar atmospheres of so-called normal galaxies, seen only one billion years after the Big Bang. This suggests that even though normal galaxies in the very early Universe were already brimming with carbon, they were not nearly as chemically evolved as similar galaxies observed just a few billion years...

Read More........→July 16, 2015