Category Astronomy/Space

3 steps astronomers used to measure the universe’s expansion rate (Hubble constant) to an unprecedented accuracy, reducing the total uncertainty to 2.3 percent. The measurements streamline and strengthen the construction of the cosmic distance ladder, which is used to measure accurate distances to galaxies near to and far from Earth. The latest Hubble study extends the number of Cepheid variable stars analyzed to distances of up to 10 times farther across our galaxy than previous Hubble results

Astronomers have used Hubble to make the most precise measurements of the expansion rate of the universe since it was first calculated nearly a century ago. Intriguingly, the results are forcing astronomers to consider that they may be seeing evidence of something unexpected at work in the universe...

Europa has an enormous ocean of warm liquid water under its frozen crust. The bottom of this ocean could be a similar environment to primitive Earth, potentially hosting microorganisms. Credit: NASA

Brazilian scientists compare primitive Earth scenario with satellite Europa’s conditions; the jupiterian moon could host microorganisms at the bottom of a huge warm ocean located underneath its frozen crust. Jupiter’s icy moon Europa is a major target of astrobiology research in light of the possibility that it offers a habitable environment in the Solar System. Under its ice crust, estimated to be 10 km thick, is an ocean of liquid water of over 100 km deep. A huge source of energy deriving from gravitational interaction with Jupiter keeps this water warm.

Theoretical research to evaluate the ...

If the Moon has enough water, and if it’s reasonably convenient to access, future explorers might be able to use it as a resource. Credit: NASA’s Goddard Space Flight Center

A new analysis of data from two lunar missions finds evidence that the Moon’s water is widely distributed across the surface and is not confined to a particular region or type of terrain. The water appears to be present day and night, though it’s not necessarily easily accessible. The findings could help researchers understand the origin of the Moon’s water and how easy it would be to use as a resource. If the Moon has enough water, and if it’s reasonably convenient to access, future explorers might be able to use it as drinking water or to convert it into hydrogen and oxygen for rocket fuel or oxygen to breathe.

“We f...

In this series of images, the magnetic rope, in blue, grows increasingly twisted and unstable. But it never erupts from the Sun’s surface: The model demonstrates the rope didn’t have enough energy to break through the magnetic cage, in yellow. Credit: Tahar Amari et al./Center for Theoretical Physics/École Polytechnique/NASA Goddard/Joy Ng

A dramatic magnetic power struggle at the Sun’s surface lies at the heart of solar eruptions, new research using NASA data shows. The work highlights the role of the Sun’s magnetic landscape, or topology, in the development of solar eruptions that can trigger space weather events around Earth.

The scientists, led by Tahar Amari, an astrophysicist at the Center for Theoretical Physics at the École Polytechnique in Palaiseau Cedex, France, considered sola...