Asteroids Archives

March 1, 2023March 1, 2023 by Evan Gough

Remember the DART impact? Hubble Made a Movie of the Debris

This Hubble image shows debris from Dimorphos about one day after NASA's DART spacecraft slammed into it. Image Credit: NASA, ESA, STScI, J. Li (PSI)

When NASA crashed a 610 kg (1,340 lb) impactor into tiny Dimorphos, a moon of the asteroid Didymos, it was all part of an effort to defend Earth. The impact showed how asteroids respond to impacts, and the data is helping NASA prepare for the day when we have to redirect an asteroid away from an eventual impact with Earth.

NASA’s DART (Double Asteroid Redirection Test) smashed into Dimorphos on the 26th of September, 2022, and ground telescopes watched the result.

February 24, 2023February 24, 2023 by Carolyn Collins Petersen

Recreating the Extreme Forces of an Asteroid Impact in the Lab

Barringer Meteor Crater in Arizona. Scientists studied the forces in the event that created this impact scar. Image credit: NASA

About 50,000 years ago, a nickel-iron meteorite some 50 meters across plowed into the Pleistocene-era grasslands of what is now Northern Arizona. It was traveling fast—about 13 kilometers per second. In just a few seconds, an impact dug out a crater just over a kilometer wide and spread rocks from the site for miles around.

February 22, 2023February 22, 2023 by Carolyn Collins Petersen

Astronomers Find a Group of Water-rich Asteroids

Artist's conception of a solar system in formation. It's likely that exoplanet formation around other stars proceeded similarly. Credit: NASA/FUSE/Lynette Cook

If you’ve ever been at sea or visited a seacoast, you probably looked out at the vast expanse of ocean and wondered, “How did all this water get here?” The answer goes back to Earth’s origins some 4.5 billion years ago. In those early times, water-rich planetesimals and other bodies transported water to our still-growing planet. A recent discovery of a previously unknown population of such asteroids between Mars and Jupiter seems to prove that point.

February 21, 2023February 21, 2023 by Nancy Atkinson

A 500-Meter-Long Asteroid Flew Past Earth, and Astronomers Were Watching

This collage shows six planetary radar observations of 2011 AG5 a day after the asteroid made its close approach to Earth on Feb. 3. With dimensions comparable to the Empire State Building, 2011 AG5 is one of the most elongated asteroids to be observed by planetary radar to date. Credit: NASA/JPL-Caltech

An asteroid the size of the Empire State Building flew past Earth in early February, coming within 1.8 million km (1.1 million miles) of our planet. Not only is it approximately the same size as the building, but astronomers found the asteroid – named 2011 AG5 — has an unusual shape, with about the same dimensions as the famous landmark in New York City.

“Of the 1,040 near-Earth objects observed by planetary radar to date, this is one of the most elongated we’ve seen,” said Lance Benner, principal scientist at JPL who helped lead the observations, in a JPL press release.

This extremely elongated asteroid has a length-to-width ratio of 10:3.

February 18, 2023February 18, 2023 by Nancy Atkinson

ESA is Building an Early Warning System for Dangerous Asteroids

A graphic showing the concept for the NEOMIR orbiting observatory will act as an early warning system to detect and monitor any asteroid coming towards Earth from the Sun’s direction. Credit: ESA.

The European Space Agency is working on a new mission that would act as an early warning system for dangerous, hard-to-see asteroids. Called NEOMIR (Near-Earth Object Mission in the InfraRed), the spacecraft would orbit between the Earth and the Sun at the L1 Lagrange Point, finding space rocks that otherwise get lost in the glare of the Sun.

February 14, 2023February 14, 2023 by Nancy Atkinson

Another Meteoroid Discovered Right Before it Hits the Atmosphere

A meteoroid lights up the sky over the English Channel on February 12, 2023. Image courtesy of Muhammed Uzzal, via ESA.

A meteoroid lit up the sky above the English Channel early Monday morning February as it streaked through the atmosphere, and because it had been detected just a few hours beforehand – with expert precision on where it could be seen — skywatchers were able to capture the event.

Astronomer Krisztián Sárneczky found the 1-meter (3 ft) asteroid just half a day before it came through Earth’s atmosphere. Sárneczky used 60-cm Schmidt telescope at the Piszkéstet? Observatory in Hungary, and originally named it Sar2667. After multiple observations, the object was re-designated as 2023 CX1 and was predicted with 100% certainty to hit Earth in the skies above the English Channel. Astronomers continued to track the object, then it blazed through the atmosphere over Europe right on schedule.

February 6, 2023February 6, 2023 by Nancy Atkinson

JWST Unexpectedly Finds a Small Asteroid During ‘Failed’ Observations

Illustration of Asteroid (Artist’s Impression). Credit: N. Bartmann (ESA/Webb), ESO/M. Kornmesser and S. Brunier, N. Risinger

While astronomers and engineers were trying to calibrate one of the James Webb Space Telescope’s instruments last summer, they serendipitously found a previously unknown small 100–200-meter (300-600 ft) asteroid in the main asteroid belt. Originally, the astronomers deemed the calibrations as a failed attempt because of technical glitches. But they noticed the asteroid while going through their data from the Mid-InfraRed Instrument (MIRI), and ended up finding what is likely the smallest object observed to date by JWST. It is also one of the smallest objects ever detected in our Solar System’s main belt of asteroids.

“We — completely unexpectedly — detected a small asteroid in publicly available MIRI calibration observations,” explained Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany, in a press release. “The measurements are some of the first MIRI measurements targeting the ecliptic plane and our work suggests that many, new objects will be detected with this instrument.”

January 31, 2023January 31, 2023 by Evan Gough

Don’t Bother Trying to Destroy Rubble Pile Asteroids

Detailed view of the rubble-pile asteroid 25143 Itokawa visited by the Japanese spacecraft Hayabusa in 2005. Credit: JAXA

The asteroids in our Solar System are survivors. They’ve withstood billions of years of collisions. The surviving asteroids are divided into two groups: monolithic asteroids, which are intact chunks of planetesimals, and rubble piles, which are made of up fragments of shattered primordial asteroids.

It turns out there are far more rubble pile asteroids than we thought, and that raises the difficulty of protecting Earth from asteroid strikes.

January 27, 2023January 27, 2023 by Nancy Atkinson

Truck-Sized Asteroid Flew Past Earth Yesterday, Coming Within 3,600 km

Near-Earth Asteroid 2023 BU seen as it passed Earth on January 26, 2023. Credit: Gianluca Masi, Virtual Telescope Project.

On January 26, a truck-sized asteroid flew past Earth, coming extremely close – within 3,600 km (2,200 miles) above the planet’s surface. This is well within the orbit of geosynchronous satellites and NASA says this flyby is one of the closest approaches by a near-Earth object ever recorded.

The asteroid, named 2023 BU’s has an estimated size of 3.5m to 8.5m across (11.5ft to 28ft). Italian astronomer Gianluca Masi, who leads the Virtual Telescope Project, captured images and video of the flyby and said a huge audience joined in for the live feed. At its closest approached, it zoomed over the southern tip of South America at about 4:27 p.m. PST (7:27 p.m. EST.)

January 26, 2023January 26, 2023 by Evan Gough

Lucy Adds Another Asteroid to its Flyby List

This artist's illustration shows NASA's Lucy spacecraft close to one of its targets. NASA has added another asteroid, the eleventh, to Lucy's mission. Image Credit: NASA/SWRI/GSFC

In October 2021, NASA launched its ambitious Lucy mission. Its targets are asteroids, two in the main belt and eight Jupiter trojans, which orbit the Sun in the same path as Jupiter. The mission is named after early hominin fossils (Australopithecus afarensis,) and the name pays homage to the idea that asteroids are fossils from the Solar System’s early days of planet formation.

Visiting ten asteroids in one mission is the definition of ambitious, and now NASA is adding an eleventh.