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Protecting ALMA’s Skies

Protecting ALMA’s Skies

The Atacama Large Millimeter/submillimeter Array (ALMA), renowned for observing the cosmos’s darkest and most distant corners, has taken a step to ensure its observations remain unaffected by human-made interference.

At the heart of ALMA’s exceptional capabilities lies its extensive frequency range, spanning from 35 GHz to 950 GHz in ten distinct frequency bands. This comprehensive range is vital for ALMA’s mission to unlock the Universe’s secrets. However, it also exposes the observatory to potential RFI from both terrestrial and space-based sources.

A recently concluded study, led by senior radio frequency (RF) engineer and Spectrum Manager Giorgio Siringo, alongside ALMA Director Sean Dougherty, presents an extensive analysis of the current and future challenges of radio frequency interference (RFI) to ALMA’s operations. This white paper, “ALMA Spectrum and Radio Frequency Interference,” meticulously identifies vulnerabilities from sources of interference and proposes robust mitigation measures to safeguard ALMA’s valuable observations.

The ALMA Spectrum Management Office is collaborating in Chile with the Radio Sub-Committee of the Light Pollution Working Group of the Chilean Astronomical Society (SoChiAs) and the Chilean Low-Earth Orbit Satellites Group (CLEOsat), internationally with the Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS) of the International Astronomical Union (IAU), with the National Radio Dynamic Zones (NRDZ) initiative of the National Radio Astronomy Observatory (NRAO) of the USA, and with the Committee on Radio Astronomy Frequencies (CRAF) of the European Science Foundation (ESF), and participating in the preparatory meetings for the WRC-27 of the International Telecommunication Union (ITU).

Read more at the Joint ALMA Observatory website. 

The post Protecting ALMA’s Skies appeared first on National Radio Astronomy Observatory.

ALMA Reveals Jupiter’s Moon Io has been Volcanically Active for Billions of Years

ALMA Reveals Jupiter’s Moon Io has been Volcanically Active for Billions of Years

Jupiter’s moon Io is the most volcanically active place in the solar system. During its 1.8-day orbit, this moon is gravitationally squeezed by Jupiter, leading to volcanic eruptions larger than any on Earth today.

Io, Europa, and Ganymede are in an orbital configuration known as a Laplace resonance: for every orbit of Ganymede (the farthest of the three from Jupiter), Europa completes exactly two orbits, and Io completes exactly four. In this configuration, the moons pull on each other gravitationally in such a way that they are forced into elliptical, rather than round, orbits. Such orbits allow Jupiter’s gravity to heat the moons’ interiors, causing Io’s volcanism and adding heat to the subsurface liquid ocean on icy Europa.

How long has Io been experiencing volcanic upheaval? In other words, how long have Jupiter’s moons been in this configuration?

To discover the answer, researchers utilized the ALMA (Atacama Large Millimeter/submillimeter Array) telescope in Chile—a telescope that is itself surrounded by volcanoes—to measure sulfur isotopes on Io.

Read the full press release from Caltech.

The post ALMA Reveals Jupiter’s Moon Io has been Volcanically Active for Billions of Years appeared first on National Radio Astronomy Observatory.


إدارة الرجفان الأذيني

روتشستر، ولاية مينيسوتا -- وفقًا لجمعية القلب الأمريكية، فإن ما يقرب من 3 ملايين أمريكي مصاب بحالة قلبية تسمى الرجفان الأذيني. وتصرح مراكز مكافحة الأمراض والوقاية منها أن العدد قد يصل إلى 12 مليونًا بحلول بداية العقد القادم.