Category Astronomy/Space

Astronomers Solve Dark Matter Puzzle of Strange Galaxy

Image and amplification (in colour) of the ultra-diffuse galaxy Dragonfly 44 taken with the Hubble space telescope. Many of the dots on the galaxy are the globular clusters studied in this article to explore the distribution of dark matter. The galaxy is so diffuse that other galaxies can be seen behind it. Credit: Teymoor Saifollahi and NASA/HST.
Image and amplification (in colour) of the ultra-diffuse galaxy Dragonfly 44 taken with the Hubble space telescope. Credit: Teymoor Saifollahi and NASA/HST.

Astronomers have found that the total number of globular clusters around Dragonfly 44 and, therefore, the dark matter content, is much less than earlier findings had suggested, which shows that this galaxy is neither unique nor anomalous.

At present, the formation of galaxies is difficult to understand without the presence of a ubiquitous, but mysterious component, termed dark matter. Astronomers have measure how much dark matter there is around galaxies, and have found that it varies between 10 and 300 times the quantity of visible matter...

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A new look at Sunspots

Scientists created light curves using the high-resolution images of the Sun to understand what a sunspot would look like on a distant star. They studied different layers of the Sun from the visible surface to the outer atmosphere using 14 different wavelengths, including the six shown here (top left to right: photosphere, magnetic flux of the photosphere, ultraviolet 304 angstroms; bottom left to right: ultraviolet 171 angstroms, ultraviolet 131 angstroms, x-ray).
Credits: NASA/SDO/JAXA/NAOJ/Hinode

NASA’s extensive fleet of spacecraft allows scientists to study the Sun extremely close-up — one of the agency’s spacecraft is even on its way to fly through the Sun’s outer atmosphere. But sometimes taking a step back can provide new insight.

In a new study, scientists looked at sunspots ...

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Signals from Distant Stars Connect Optical Atomic Clocks across Earth for the first time

Fig.
Antennas and optical lattice clocks used in the measurements

Upper left: Transportable 2.4 m antenna installed at the INAF radio observatory in Medicina, Italy.
Upper middle: Transportable 2.4 m antenna installed at NICT in Koganei, Japan.
Upper right: 34 m antenna located at NICT in Kashima, Japan.
Bottom left: The ytterbium optical lattice clock IT-Yb1, operated at INRIM in Torino, Italy.
Bottom right: The strontium optical lattice clock NICT-Sr1, located at NICT in Koganei, Japan.

Transportable radio telescopes could provide global high-precision comparisons of the best atomic clocks. Using radio telescopes observing distant stars, scientists have connected optical atomic clocks on different continents...

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Moon’s Magnetic Crust research sees scientists Debunk Long-held Theory

The Moon ©NASA

New international research into the Moon provides scientists with insights as to how and why its crust is magnetised, essentially ‘debunking’ one of the previous longstanding theories.
Australian researcher and study co-author Dr Katarina Miljkovic, from the Curtin Space Science and Technology Centre, located within the School of Earth and Planetary Sciences at Curtin University, explained how the new research, published by Science Advances, expands on decades of work by other scientists.
“There are two long term hypotheses associated with why the Moon’s crust might be magnetic: One is that the magnetisation is the result of an ancient dynamo in the lunar core, and the other is that it’s the result of an amplification of the interplanetary magnetic field, created by meteo...

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