Missing Lithium

The globular star cluster Messier 54Most of the light chemical element lithium now present in the Universe was produced along with hydrogen and helium during the Big Bang but in much smaller quantities. Astronomers have calculated how much lithium they expect to find in the early Universe and from this work out how much they should see in old stars. But the calculations don’t match the observed values. There is about one-third of lithium in stars that we expect to see in our galaxy, The Milky Way.

This new image from the VLT Survey Telescope at ESO’s Paranal Observatory the globular cluster Messier 54, a star cluster that doesn’t belong to the Milky Way but is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. A team of astronomers has used the VLT to measure how much lithium there is in a selection of stars in Messier 54. They find that the levels are close to those in the Milky Way. So, whatever it is that got rid of the lithium seems not to be specific to the Milky Way.

Image Credit: ESO

The History of the Universe, Part One

The Wilkinson Microwave Anisotropy Probe (WMAP) was a NASA Explorer mission that made fundamental measurements of cosmology—the study of the properties of our universe as a whole.

The structure of the universe evolved from the Big Bang, as represented by WMAP’s “baby picture” of the Cosmic Microwave Background (the afterglow of the Big Bang), through the clumping and ignition of matter, and continuing up to the present. This video condenses that almost 14 billion year history into 45 seconds.

Video Credit: NASA