Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on the day's biggest business stories

Subscribe to Axios Closer for insights into the day’s business news and trends and why they matter

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Stay on top of the latest market trends

Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sports news worthy of your time

Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tech news worthy of your time

Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Get the inside stories

Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Denver news?

Get a daily digest of the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Des Moines news?

Get a daily digest of the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Twin Cities news?

Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Tampa Bay news?

Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Charlotte news?

Get a daily digest of the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sign up for Axios NW Arkansas

Stay up-to-date on the most important and interesting stories affecting NW Arkansas, authored by local reporters

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Photo: NASA/JPL-Caltech

Future space explorers might be able to use a silica aerogel — a porous, extremely light solid material — to insulate greenhouses and other structures on Mars, a study in the journal Nature Astronomy this week shows.

Why it matters: Most schemes to allow people to live on Mars include some kind of extreme attempt to make the planet itself livable though terraforming, but the new aerogel could prove a simple and low-tech solution for habitability.

Details: The study suggests that just a 2- to 3-centimeter-thick aerogel "shield" over parts of the Martian surface could actually make those parts of the world able to sustain liquid water on the surface and even support photosynthesis.

  • The aerogel is "very light and it is an incredibly effective thermal insulator. It also is nearly transparent to visible radiation but blocks UV light," Robin Wordsworth, one of the authors of the study told Axios via email.
  • The gel could raise the temperature of the surface beneath it by as much as 122°F, helping to protect whatever is beneath it from temperatures that can dip as low as -130°F in the midlatitudes during the winter, according to NASA.
  • Wordsworth and the other authors of the study replicated conditions on Mars in a lab and then used climate models to show that the aerogel could insulate the planet's surface.

But, but, but: There's a way to go before the material is ready for the Red Planet. "Aerogel is quite fragile, so it'd need to be modified or combined with other materials to make a robust shield," Wordsworth said.

  • The scientists behind the idea are now hoping to test the aerogel on Earth in a desert or even Antarctica to see just how effective it could be on Mars.

Go deeper

D.C.'s building boom grinds to a halt

Illustration: Brendan Lynch/Axios

The decades-long building boom that remade Washington D.C. is screeching to a halt, undone by broader construction trends and the legacy of the post-pandemic workplace.

Why it matters: Dizzying construction has reshaped the city, reinvigorated downtown and created bustling new communities. 

Facebook fights for its image

Illustration: Annelise Capossela/Axios

Facebook is ditching apologies and taking a more combative stance against its critics as it faces a new barrage of negative coverage and leaked internal reports.

Driving the news: As part of the new posture, Facebook started testing placing positive messages about itself in users' News Feeds last month, according to a New York Times story Tuesday.

2 hours ago - Politics & Policy

Charter schools boomed during the pandemic

Expand chart
Data: National Alliance for Public Charter Schools; Map: Sara Wise/Axios

Charter schools picked off hundreds of thousands of public school students across the U.S. during the pandemic, according to a new analysis from the National Alliance for Public Charter Schools.

Why it matters: The pandemic has weakened America's public education system, as Zoom classes, teacher fatigue and student disengagement take their toll. And that hobbled system is shedding students to charter schools, private schools and homeschooling.