Category Astronomy/Space

Interstellar Comets like Borisov may not be all that rare

NASA, ESA and D. Jewitt (UCLA)

Astronomers calculate that the Oort Cloud may be home to more visiting objects than objects that belong to our solar system. In 2019, astronomers spotted something incredible in our backyard: a rogue comet from another star system. Named Borisov, the icy snowball traveled 110,000 miles per hour and marked the first and only interstellar comet ever detected by humans.

But what if these interstellar visitors — comets, meteors, asteroids and other debris from beyond our solar system — are more common than we think?

In a new study published Monday in the Monthly Notices of the Royal Astronomical Society, astronomers Amir Siraj and Avi Loeb at the Center for Astrophysics | Harvard & Smithsonian (CfA) present new calculations showing that in the Oort Clou...

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Under the Northern Lights: Mesospheric Ozone Layer Depletion Explained

Under the northern lights: Mesospheric ozone layer depletion explained
In geospace, the Arase satellite observes chorus waves and energetic electrons, while on the ground, EISCAT and optical instruments observe pulsating aurorae and electron precipitation in the mesosphere. Credit: ERG science team

The same phenomenon that causes aurorae—the magical curtains of green light often visible from the polar regions of the Earth—causes mesospheric ozone layer depletion. This depletion could have significance for global climate change and therefore, understanding this phenomenon is important.

Now, a group of scientists led by Prof. Yoshizumi Miyoshi from Nagoya University, Japan, has observed, analyzed, and provided greater insight into this phenomenon. The findings are published in Nature’s Scientific Reports.

In the Earth’s magnetosphere—the region of...

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Comet -ATLAS may have been a Blast from the Past

Comet ATLAS may have been a blast from the past
This pair of Hubble Space Telescope images of comet C/2019 Y4 (ATLAS), taken on April 20 and April 23, 2020, reveal the breakup of the solid nucleus of the comet. Hubble photos identify as many as 30 separate fragments. The comet was approximately 91 million miles from Earth when the images were taken. The comet may be a broken off piece of a larger comet that swung by the Sun 5,000 years ago. The comet has been artificially colored in this view to enhance details for analysis. Credit: NASA, ESA, Quanzhi Ye (UMD), Alyssa Pagan (STScI)

It’s suspected that about 5,000 years ago a comet may swept within 23 million miles of the Sun, closer than the innermost planet Mercury...

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Researchers Solve 20-year-old Paradox in Solar Physics

Researchers solve 20-year-old paradox in solar physics
Image of the solar atmosphere showing a coronal mass ejection. Credit: NASA/GSFC/SDO

In 1998, the journal Nature published a seminal letter concluding that a mysterious signal, which had been discovered while analyzing the polarization of sunlight, implies that the solar chromosphere (an important layer of the solar atmosphere) is practically unmagnetised, in sharp contradiction with common wisdom. This paradox motivated laboratory experiments and theoretical investigations, which instead of providing a solution, raised new issues, and even led some scientists to question the quantum theory of matter-radiation interaction.

Researchers at the Istituto Ricerche Solari (IRSOL) in Locarno-Monti (affiliated to USI Università della Svizzera italiana), and the Instituto de Astrofísica de C...

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