#planetary defense

[nasa]

Space Rocks!🤘But Also ️Space Rocks!☄️

Asteroids: they’re ancient, rocky, and way cooler than you might think. June 30 is International Asteroid Day, a global event to raise awareness about asteroids and what we’re doing to study them. Here’s why we’re obsessed with them (and why you should be, too).

What are asteroids?

Asteroids are leftover building blocks from the early solar system, orbiting the Sun like planetary time capsules. Most hang out in the main asteroid belt between Mars and Jupiter, but some—called Near-Earth Objects, or NEOs—orbit closer to home. They range in size from 329 miles (530 kilometers) in diameter to less than 33 feet (10 meters) across.

Why do we study them?

Studying asteroids helps us unlock the origins of our solar system. 

In 2023, our OSIRIS-REx mission collected a sample from asteroid Bennu that could reveal whether asteroids delivered water and other ingredients for life when they collided with Earth billions of years ago.

Lucy in the sky…with asteroids? Our Lucy mission, which launched in 2021, is named for a fossilized skeleton of a human ancestor, which was in turn named for the Beatles song “Lucy in the Sky with Diamonds.” Lucy is the first mission to explore asteroids that share an orbit around the Sun with Jupiter.

A timelapse of the asteroid Donaldjohanson taken on NASA’s Lucy spacecraft. The images, captured approximately every 2 seconds beginning at 1:50 p.m. EDT April 20, 2025, show a white, irregular, elongated shape rotating slowly. Its surface is covered in small craters and has a rough, uneven texture. The asteroid appears bright against a black background. Credit: NASA/Goddard/SwRI/Johns Hopkins APL

What if an asteroid hits Earth?

NASA’s Planetary Defense Program uses telescopes to keep an eye out for asteroids and other NEOs, in case any get too close for comfort. Although a catastrophic collision is highly unlikely for the next 100 years or more, the telescopes detect smaller objects on a collision course with Earth a few times per year. No need to worry—these objects are just a few feet (meters) in size and cause no damage.

Rock on!

Hungry for more? Check out our asteroid portal for a cosmic crash course, or explore a real-time visualization of every known asteroid and comet classified as an NEO with NASA’s Eyes on Asteroids app.  

Make sure to follow us on Tumblr for your regular dose of space!

[spacetelescopescience]

The Moon is under no significant threat of being impacted by asteroid 2024 YR4 in 2032, according to data from a recent observation by the James Webb Space Telescope. Astronomers had already determined that the asteroid would miss Earth.

Scientists used Webb for its unique stability and sensitivity to perform the long exposure necessary to measure such a faint object. Other observatories would have to wait until 2028—when the asteroid made its next passage through our inner solar system—to make similar measurements.

Learn why Webb plays a crucial role in planetary defense: https://go.nasa.gov/40bCbtL

[old-type-40]

The DART team did it! This is the first successful test for planetary defense with the spacecraft hitting the asteroid at 14000 mph (22500 kph) using an automated guidance system.

[odinsblog]

While most folks were sitting down for supper, NASA tried to move a space mountain.

Beyond sight for backyard stargazers, a spacecraft the size of a vending machine self-destructed by ramming into a harmless asteroid shortly after 7 p.m. ET Monday, September 26th. The high-speed crash was part of the U.S. space agency's Double Asteroid Redirection Test, or DART.

The moment of impact marked the first time in history humans have attempted to alter the path of an asteroid, a flying chunk of rubble left over from the formation of the solar system about 4.6 billion years ago. Most of the time, these ancient rocks pose no danger to Earth, including Dimorphos, the one NASA just used for target practice. But at least three have caused mass extinctions, the most infamous of which wiped out the dinosaurs.

Stegosaurus didn't have NASA.

"We are changing the motion of a natural celestial body in space. Humanity has never done that before," said Tom Statler, program scientist. "This was the substance of fiction books and really corny episodes of Star Trek from when I was a kid, and now it's real."

(continue reading)

[aspaceinthecosmos]

IMPACT!

(sped up)

the DART mission has collided with the asteroid Dimorphos!

Dimorphos, a small asteroid orbiting the larger Didymos, has been hit at 4 miles/second (6.4km/s) by nasa’s DART spacecraft, in order to test our planetary defense systems.

(an important note: neither of these two asteroids have any chance of collision with earth, this mission was simply to try and redirect an asteroid in case it’s ever needed)

next, scientists will train their telescopes on the asteroid system, hoping to notice differences in Dimorphos’ orbit, meaning we’ve successfully changed its orbit by a spacecraft!

[lizardposting]

the best part of watching the nasa livestream where they tried out planetary defense against an asteroid was watching the scientists cry and hug each other at impact <3

[mckitterick]

say hello to the new UFO logo for the National Intelligence Manager for the Air Domain

see that little flying saucer west of Columbia?

a closer view of the logo as a patch

close-up of the UFO

they seriously posted this for about a day. also note the Turkish Bayraktar TB-2 drone over the Rockies, the Chinese hypersonic glide vehicle just reaching the Arctic, and the fighter jet over the Southeast USA that appears to be a Russian Sukhoi Su-57 Felon (the rearmost jet is a passenger liner)

NIM-A is the government intelligence agency that co-authored with the Pentagon last summer's report on "unidentified aerial phenomena" aka UFOs

they took down the new logo after the UFO community began going wild, but the fact they made it is just... wow

more in the PopMech story: X

[kreuzaderny]

National Preparedness Strategy and Action Plan for Near-Earth Object Hazards and Planetary Defense