Summer Star Shower: Watch the Perseids with NASA! - Watch the Skies

The constellation Orion is framed by two Perseid meteors on Aug. 12, 2018, in Cedar Breaks National Monument, Utah.

NASA/Bill Dunford

The Perseids are back! One of the year’s brightest and most popular meteor showers has been ramping up since early July and will sparkle in the skies through the end of August. The shower reaches its peak on the night of Aug. 12 into the early morning of Aug. 13, and its visibility should be ideal thanks to the new Moon phase that will keep the skies dark.

True to our blog’s name, we want to watch the skies with you. Join us as we stay up late to catch the show on our sky cameras. We will be livestreaming a meteor watch party starting at midnight ET on Aug. 13 on YouTube. Throughout the night, we’ll talk to meteor experts, watch live views of the skies, and answer your questions.

We’ll be watching from cameras set up at Marshall Space Flight Center’s ALaMO – the Automated Lunar and Meteor Observatory, which is celebrating 20 years of discovery this year. We will also share sky views from the International Space Station. During the peak, the shower can produce as many as 50-100 meteors per hour if viewing conditions are right.

The Perseids are among the oldest recorded meteor showers, with observations dating back more than 2,000 years. They are a favorite annual event because they are reliably active and visible, take place in warmer months, and are known for producing fireballs – exceptionally bright meteors that leave a glowing trail as they streak across the sky.

The Perseids are so named because the meteors appear to radiate from the constellation Perseus, which is visible in the northern sky. In Greek mythology, Perseus is the warrior who slayed Medusa and rescued Princess Andromeda, whose namesake constellation shares the sky nearby. But don’t worry too much about finding Perseus to catch a glimpse of shooting stars. Meteors can appear anywhere overhead.

The best way to watch the Perseid meteor shower is to find a location with dark skies, give your eyes 20 to 30 minutes to adjust to the darkness, and simply look up. Then sit back, be patient, and enjoy one of the year’s premier celestial shows. 

Source: Summer Star Shower: Watch the Perseids with NASA! - NASA 

The Sun’s Surface Is Covered in Tiny Whirlpools, And They Might Solve a Decades-Old Mystery

The newest, sharpest image ever taken of the Sun doesn’t just look striking, it confirms something solar physicists have suspected for decades but never actually seen. Captured by the NSF Daniel K. Inouye Solar Telescope in Hawai’i, the world’s largest solar telescope, the image reveals flower-like structures spanning roughly the radius of Earth, with details as fine as a single city. And at the edges of those structures, researchers found exactly what they were looking for: swirls.

The phenomenon is called Kelvin-Helmholtz instability (KHI), a well-known process that occurs whenever two fluids or gases flow past each other at different speeds, creating waves and eventually spiraling vortices. It shows up in clouds on Earth, in the bands of Jupiter and Saturn, and at the boundary of Earth’s magnetosphere. On the Sun, it had long been theorized to occur in the solar photosphere, where streams of magnetic plasma flow past one another, but no instrument had ever had the resolution to actually catch it happening, until now.

Using the Inouye telescope’s FastCam imager, built jointly by the National Solar Observatory and Germany’s Max Planck Institute for Solar System Research, an international team captured time-lapse footage showing small-scale, dynamic swirls at the edges of magnetic regions across the Sun’s surface. Combined with numerical simulations, the observations gave researchers their first unambiguous confirmation of KHI happening on a star.

Why does it matter? These swirling vortices may be a missing piece in one of solar physics’ most stubborn puzzles: why the Sun’s outer atmosphere, the corona, is over a hundred times hotter than the surface below it. KHI is a known mechanism for mixing plasma and building up magnetic energy, the same magnetic energy that eventually powers solar flares and coronal mass ejections capable of disrupting satellites and power grids on Earth. Researchers now suspect these tiny whirlpools may help explain how energy and magnetic fields move around and build up on the Sun, feeding directly into the space weather that reaches us.

The finding also demonstrates just how much remains hidden in the Sun’s surface dynamics at scales we’ve only just become able to resolve. As the Inouye telescope continues observing, researchers expect KHI to become a foundational piece of how we model the Sun’s atmosphere going forward.

Original paper: Ubiquitous Kelvin–Helmholtz instabilities driving plasma mixing on the Sun

Image Credit: NSF, NSO, AURA, MPS, Inouye Tel. 

Source: The Sun’s Surface Is Covered in Tiny Whirlpools, And They Might Solve a Decades-Old Mystery