Cosmic Expansion Uncertainties

6 Jan 2021

At ... There are different methods for determining the cosmic rate of expansion of the universe, and these have revealed precise but mutually inconveniently different results. Astronomers, or should that be cosmologists, had hoped so called gravitational waves would bring some certainty but these have also produced uncertainties, as significant as in other methods, a ten per cent level of disagreement. That seems to be quite substantial. According to Hsin Yu-Chen of Cornell these are due to the varying angle of the source from the point of view of the sight line.

At ... the oldest bit of the universe, it is said, suggests the universe is 13.77 billion years of age, using data from the Atacama Telescope Array. Unsurprisingly, this result is close to the one provided by the standard model of the universe as well as measurements of the moment of Big Bang. These involve measurements of a distant light source as made by ESAs Planck satellite. Measuring the moment of the Big Bang.

At ... there is a nice image of the layer of rock in Candor Chasma on Mars. It is said to be the Martian equivalent of the rent in the earth, the Grand Canyon. Scientists have a problem though as the Martian split in the crust could not be caused by flowing water, such as a river cutting down into rock strata. There is no river. Not only that but Candor is 4000km in length and 7 km deep. That is a big scar. The image itself was taken by the Mars Reconnaissance Orbiter. It reveals layers of sedimentary rocks suggesting a depositional process of some kind. Other images of the red planet show jagged head rock features and gully like channels.

At ... we are told there are 6  space missions this year, 2021. NASAs Artemis project - astronauts back on the moon by 2024, while in February Mars will be host to 3 robotic missions by the Arab Emirates, China and the US. Then we have an Indian mission to the moon, the third since 2008, and the launch of the James Webb Space Telescope.