Connect with us

Published

1 month ago

on

In the hunt for habitable worlds around other stars, planetary atmospheres provide fertile places to look. But, as a group of scientists at the Max-Planck Institute for Solar System Studies in Germany found, maybe astronomers should focus on a star’s metallicity, too. That’s because there seems to be a direct link between their metallicity, how much UV radiation they give off, and the atmospheres of rocky planets orbiting them. It turns out that metal-poor stars provide better conditions for life on their planets than metal-rich ones do.

What led the science team to make that link? It all started with a study a few years ago that compared the Sun’s brightness variations with those of many other similar-type stars. Some of those stars showed huge intensity stronger than the Sun’s. “We saw huge peaks in intensity”, says Dr. Alexander Shapiro, who was involved in that work. “It is therefore quite possible, that the Sun, too, is capable of such spikes in intensity. In that case, also the intensity of the ultraviolet light would increase dramatically.”

That raised the question about what such huge outbursts could mean for life on Earth. And, if those spikes happened elsewhere, how it might affect the chances of life on other worlds? In addition, what role does ultraviolet radiation play? So, the researchers did another study. This time, they looked at the UV flux from other stars and compared them to our own star and its effects on our planet. “In the Earth’s atmospheric chemistry, ultraviolet radiation from the Sun plays a dual role,” explained Dr. Anna Shapiro, whose past research interest focused on the influence of solar radiation on Earth’s atmosphere. In interactions with our planet’s atmosphere, it helped thicken the protective ozone layer.

UV Radiation, Ozone, and Planetary Atmospheres

How does that thickening happen? Reactions between different types of UV radiation and individual oxygen atoms and oxygen molecules create and destroy ozone. While long-wave UV-B radiation destroys ozone, short-wave UV-C radiation helps create protective ozone in the middle atmosphere of a planet. “It was therefore reasonable to assume that ultraviolet light may have a similarly complex influence on exoplanet atmospheres as well,” she said. The precise wavelengths play a crucial role and so the astronomers calculated exactly which ones make up the UV emitted by stars.

A graphic illustration of how different-metallicity stars help
A graphic illustration of how different-metallicity stars help “grow” ozone layers on nearby planets. Those layers help protect life on the surface if it exists. Courtesy MPS/hormesdesign.de

This is where the metallicity of a star comes into play. Think of metallicity as the ratio of hydrogen in a star compared to other “heavy” elements such as oxygen, carbon, and iron. Low-metallicity stars generally have more hydrogen than anything else. High-metallicity stars (such as one called HD 222925) can have significantly more heavy elements. The Max Planck scientists compared stars like the Sun with others having lower or higher metal content than our star. They created simulations to investigate the variety of conditions at exoplanets that could exist around all types of stars.

In particular, they wanted to estimate the UV radiation effect on hypothetical atmospheres. They also looked at the history of Earth’s atmosphere, particularly over the last half-billion years. That’s the high atmospheric oxygen content and the ozone layer were established. Those allowed the evolution of life on land on our planet. “It is feasible that the history of the Earth and its atmosphere holds clues about the evolution of life that may also apply to exoplanets,” said Jos Lelieveld, Managing Director of the Max Planck Institute for Chemistry, who was involved in the study.

Linking Metallicity to UV Radiation … and Life in the Future

After all the comparisons and simulations were done, the science team was surprised to find that metal-poor stars emit more UV radiation than metal-rich ones do. In fact, in metal-poor stars, the UV-C radiation is stronger. It enables the creation
Did you miss our previous article…
https://mansbrand.com/nasa-wants-new-ideas-for-launching-lunar-payloads-and-unlocking-climate-science/

Total
0
Shares
Share 0
Tweet 0
Pin it 0
Share 0
Related Topics:
Continue Reading

Frontier Adventure

The Best Backpacking Gear for the John Muir Trail

Published

10 hours ago

on

June 5, 2023

By

Wind4 016 2

By Michael Lanza

So you’re planning to thru-hike the John Muir Trail and making all of the necessary preparations, and now you’re wondering: What’s the best gear for a JMT hike? Having thru-hiked the JMT as well as taken numerous other backpacking trips all over the High Sierra—mostly between late August and late September, which I consider that the best time to walk the Sierra, to avoid snow and the voracious mosquitoes and blazing hot afternoons of mid-summer—I offer the following picks for the best lightweight backpacking gear and apparel for a JMT thru-hike.

Indisputably one of the best backpacking trips in America—and among the very best I’ve taken over three decades of backpacking, including 10 years I spent as Northwest Editor and lead gear reviewer for Backpacker magazine and even longer running this blog—the JMT meanders for 211 miles through the magnificent High Sierra, from Yosemite Valley to the summit of the highest peak in the Lower 48, 14,505-foot Mount Whitney (where backpackers must then descend another 11 miles to finish the trip at Whitney Portal trailhead). See my story about thru-hiking the JMT in seven days.

With few opportunities to resupply along the trail—and given the generally dry weather in the Sierra in summer—you can easily and should hike the JMT with the lightest gear that works for you (or that you can afford). Maximum pack weight will depend on how many days you spend on the trail and your food weight, but it’s quite feasible to keep your base pack weight (everything but food and water) within 15 pounds or less—and certainly no more than 20 pounds—without compromising safety or comfort in camp.

Wind4 016 3
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-guides to classic backpacking trips. Click here to learn how I can help you plan your next trip.

A backpacker hiking the John Muir Trail above Helen Lake in Kings Canyon N.P., High Sierra.
” data-image-caption=”Marco Garofalo backpacking the John Muir Trail above Helen Lake in Kings Canyon N.P. Click photo to learn how I can help you plan your JMT thru-hike.
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/10/JMT2-085-Marco-Garofalo-hiking-above-Helen-Lake-John-Muir-Trail-Kings-Canyon-N.P.-High-Sierra..jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/10/JMT2-085-Marco-Garofalo-hiking-above-Helen-Lake-John-Muir-Trail-Kings-Canyon-N.P.-High-Sierra..jpg?fit=900%2C600&ssl=1″ decoding=”async” width=”900″ height=”600″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/10/JMT2-085-Marco-Garofalo-hiking-above-Helen-Lake-John-Muir-Trail-Kings-Canyon-N.P.-High-Sierra..jpg?resize=900%2C600&ssl=1″ alt=”A backpacker hiking the John Muir Trail above Helen Lake in Kings Canyon N.P., High Sierra.” class=”wp-image-54840″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/10/JMT2-085-Marco-Garofalo-hiking-above-Helen-Lake-John-Muir-Trail-Kings-Canyon-N.P.-High-Sierra..jpg?resize=1024%2C683&ssl=1 1024w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/10/JMT2-085-Marco-Garofalo-hiking-above-Helen-Lake-John-Muir-Trail-Kings-Canyon-N.P.-High-Sierra..jpg?resize=300%2C200&ssl=1 300w, https://i0.wp.com/thebigoutside
Did you miss our previous article…
https://mansbrand.com/crs-28-mission-control-audio/

Continue Reading

Frontier Adventure

CRS-28 Mission Control Audio

Published

12 hours ago

on

June 5, 2023

By

hqdefault 2

hqdefault 3

This is the vehicle trajectory and mission control audio without any additional commentary. There may be very long periods of silence. For our full hosted webcast, visit

Did you miss our previous article…
https://mansbrand.com/photo-gallery-36-gorgeous-backcountry-lakes/

Continue Reading

Frontier Adventure

Photo Gallery: 36 Gorgeous Backcountry Lakes

Published

13 hours ago

on

June 5, 2023

By

Wind4 016

By Michael Lanza

Water makes up about 60 percent of our bodies—and, I suspect, 100 percent of our hearts. We crave it not only physically, for survival, but emotionally, for spiritual rejuvenation. We love playing in it for hours as children and we paddle and swim in it as adults. We’re drawn by the calming effects of sitting beside a stream or lake in a beautiful natural setting, an experience that possesses a certain je ne sais quoi—a quality difficult to describe, but that we can all feel.

And nothing beats taking a swim in a gorgeous backcountry lake.

I’ve come across quite a few wonderful backcountry lakes over more than three decades of exploring wilderness—including about 10 years as the Northwest Editor of Backpacker magazine and even longer running this blog. I’ve just updated and expanded this list of my favorites to give you some eye candy as well as ideas for future adventures—and perhaps compare against your list of favorite backcountry lakes.

Wind4 016 1
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-guides to classic backpacking trips. Click here to learn how I can help you plan your next trip.

Click on the links to my stories in these brief writeups to learn more about each of these trips. Much of this story is free for anyone to read, but reading the entire story requires a paid subscription. See my Custom Trip Planning page to learn how I can help you plan a trip to any of these lakes.

If you know some gorgeous lakes that are not on my list, please suggest them in the comments section below this story. I try to respond to all comments.

Here’s to your next peaceful moment beside a gorgeous lake deep in the mountains somewhere.

Elizabeth Lake in Glacier National Park.
” data-image-caption=”Early morning at Elizabeth Lake in Glacier National Park. Click photo to learn how I can help you plan your Glacier trip.
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?fit=900%2C600&ssl=1″ decoding=”async” width=”900″ height=”600″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?resize=900%2C600&ssl=1″ alt=”Elizabeth Lake in Glacier National Park.” class=”wp-image-38774″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?resize=1024%2C683&ssl=1 1024w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?resize=300%2C200&ssl=1 300w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?resize=768%2C512&ssl=1 768w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?resize=1080%2C720&ssl=1 1080w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2020/03/Gla6-018-Elizabeth-Lake-in-Glacier-National-Park.-2.jpg?w=1200&ssl=1 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />Elizabeth Lake in Glacier National Park.

Elizabeth Lake, Glacier National
Did you miss our previous article…
https://mansbrand.com/astronomers-are-searching-for-a-galaxy-wide-transmitter-beacon-at-the-center-of-the-milky-way/

Continue Reading

Trending