Category Astronomy/Space

‘Surfing’ Particles: Physicists solve a Mystery surrounding Aurora Borealis

The aurora borealis’ swirling curtains of green light, captured in Alaska by photographer Jean Beaufort.

The spectacularly colorful aurora borealis — or northern lights — that fills the sky in high-latitude regions has fascinated people for thousands of years. Now, a team of scientists has resolved one of the final mysteries surrounding its origin.

Scientists know that electrons and other energized particles that emanate from the sun as part of the “solar wind” speed down Earth’s magnetic field lines and into the upper atmosphere, where they collide with oxygen and nitrogen molecules, kicking them into an excited state. These molecules then relax by emitting light, producing the beautiful green and red hues of the aurora.

What has not been well understood is precisely how group...

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Cosmic Cartographers Map Nearby Universe revealing the Diversity of Star-Forming Galaxies

Credit: ALMA (ESO/NAOJ/NRAO)/PHANGS, S. Dagnello (NRAO)

Study reveals that the makeup and life cycle of star-forming clouds is dependent on location. A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has completed the first census of molecular clouds in the nearby Universe, revealing that contrary to previous scientific opinion, these stellar nurseries do not all look and act the same. In fact, they’re as diverse as the people, homes, neighborhoods, and regions that make up our own world.

Stars are formed out of clouds of dust and gas called molecular clouds, or stellar nurseries. Each stellar nursery in the Universe can form thousands or even tens of thousands of new stars during its lifetime...

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The Origin of the First Structures formed in Galaxies like the Milky Way identified

An example of a nearby spiral galaxy, M81, where the bulge is easily identified as the central redder part, and the disc, dotted with zones where stars are currently forming and appear as blue regions forming spiral arms. Credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA.
An example of a nearby spiral galaxy, M81, where the bulge and the disc are easily identified. Credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA.

An international team of scientists led from the Centre for Astrobiology (CAB, CSIC-INTA), with participation from the Instituto de Astrofísica de Canarias (IAC), has used the Gran Telescopio Canarias (GTC) to study a representative sample of galaxies, both disc and spheroidal, in a deep sky zone in the constellation of the Great Bear to characterize the properties of the stellar populations of galactic bulges. The researchers have been able to determine the mode of formation and development of these galactic structures. The results of this study were recently published in The Astrophysical Journal.

The researchers focused their study ...

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Did Heat from Impacts on Asteroids provide the Ingredients for Life on Earth?

 Relationship between maximum temperature and dimensionless distance. B. Relationship between duration and dimensionless distance.
Duration is scaled by thermal diffusion (*6) time. The colors indicate different projectiles and impact speeds: PC is a polycarbonate sphere with a diameter of 4.7mm and Al is an aluminum sphere with a diameter of 2mm.

A research group from Kobe University has demonstrated that the heat generated by the impact of a small astronomical body could enable aqueous alteration (*1) and organic solid formation to occur on the surface of an asteroid. They achieved this by first conducting high-velocity impact cratering experiments using an asteroid-like target material and measuring the post-impact heat distribution around the resulting crater...

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