Asteroids Archives

May 17, 2023May 12, 2023 by Paul M. Sutter

Astronomers Prepare for the Next Thousand Years of Hazardous Asteroid Impacts

This diagram shows the orbits of 2,200 potentially hazardous objects as calculated by JPL’s Center for Near Earth Object Studies (CNEOS). Highlighted is the orbit of the double asteroid Didymos, the target of NASA’s Double Asteroid Redirect Test (DART) mission. Credit: NASA/JPL-Caltech

It is as inevitable as the rising of the Sun and the turning of the tides. Someday another large rock from space will crash into the Earth. It has happened for billions of years in the past and will continue to happen for billions of years into the future. So far humanity has been lucky, as we have not had to face such a catastrophic threat. But if we are to survive on this planet for the long term, we will have to come to terms with the reality of hazardous asteroids and prepare ourselves.

May 16, 2023May 16, 2023 by Alan Boyle

Astronomers Want Your Help to Identify Risky Asteroids

The Catalina Sky Survey 60-inch telescope observes the cosmos from Mount Lemmon in Arizona. (Credit: Catalina Sky Survey)

You, too, can be an asteroid hunter — thanks to a citizen-science project launched by the University of Arizona’s Lunar and Planetary Laboratory. And you might even get a scientific citation.

The project is enlisting human spotters to verify potential detections of space rocks moving through the field of view of the Catalina Sky Survey’s telescopes. The NASA-funded survey is charged with keeping track of more than a million asteroids, with a principal goal of identifying near-Earth objects that could pose a risk to our planet.

More than 14,400 near-Earth objects, or NEOs, have been discovered by the Catalina Sky Survey during the past 30 years, including 1,200 that were identified just in the past year. That adds up to nearly half of the known NEO population.

The problem is, astronomers know there are still lots of unknown asteroids out there — too many for them to spot without an assist from amateurs. “We take so many images of the sky each night that we cannot possibly look through all of our potential real asteroids,” Carson Fuls, a science engineering specialist for the Catalina Sky Survey, said in a NASA news release. That’s where the Daily Minor Planet can make a difference.

May 3, 2023May 3, 2023 by Evan Gough

Is This Nearby Asteroid a Chunk of the Moon?

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

The Moon dominates our view of the night sky. But it’s not the only thing orbiting Earth. A small number of what scientists call quasi-satellites also orbit Earth.

One of them is called Kamo’oalewa, and it’s a near-Earth asteroid. It’s similar to the Moon in some respects. Could it be a chunk of the Moon?

April 24, 2023April 24, 2023 by Nancy Atkinson

Here's How NASA is Planning to Protect Earth From Asteroids and Comets

The large impact craters dotting our planet are powerful reminders that asteroids and comets strike the Earth from time to time. As often said, it’s not a question of “if”; it’s a matter of “when” our planet will face an impending strike from space. But an impact is one existential threat humanity is finally starting to take seriously and wrap its head around.

Seemingly spurred by the success of the Double Asteroid Redirection Test (DART), NASA just released a new planetary defense strategy and action plan, describing its efforts to find and identify potentially hazardous objects to provide an advanced warning, and then even push them off an impact trajectory.

This 10-year strategy looks to advance efforts to protect the Earth from a devastating encounter with a Near Earth asteroid or comet.

March 22, 2023March 22, 2023 by Nancy Atkinson

Another Look at the Aftermath of DART's Impact Into Dimorphos

This artist’s illustration shows the ejection of a cloud of debris after NASA’s DART spacecraft collided with the asteroid Dimorphos. Credit: ESO/M. Kornmesser

When the DART spacecraft slammed into asteroid Dimorphos on September 26, 2022, telescopes worldwide (and in space) were watching as it happened. But others continued watching for numerous days afterward to observe the cloud of debris. DART’s (Double Asteroid Redirection Test) intentional impact was not only a test of planetary defense against an asteroid hitting our planet, but it also allowed astronomers the chance to study Dimorphos, a tiny moon or companion to asteroid Didymos.

New images released by the European Southern Observatory’s Very Large Telescope (VLT) show how the surface of the asteroid changed immediately after the impact when pristine materials from the interior of the asteroid were exposed. Other data tracked the debris’ evolution over a month, and provided details on how the debris changed over time. Additionally, astronomers searched for evidence of DART’s fuel but couldn’t find any.

March 13, 2023May 7, 2023 by Alan Boyle

Don’t Panic Over the Risk of an Asteroid Smashup in 2046

NASA visualization of asteroid 2023 DW — A visualization from NASA's "Eyes on Asteroids" app shows asteroid 2023 DW's location in space. (Credit: NASA)

A newly discovered asteroid called 2023 DW has generated quite a buzz over the past week, due to an estimated 1-in-670 chance of impact on Valentine’s Day 2046. But despite a NASA advisory and the resulting scary headlines, there’s no need to put an asteroid doomsday on your day planner for that date.

The risk assessment doesn’t have as much to do with the probabilistic roll of the cosmic dice than it does with the uncertainty that’s associated with a limited set of astronomical observations. If the case of 2023 DW plays out the way all previous asteroid scares have gone over the course of nearly 20 years, further observations will reduce the risk to zero. (Update: After further observations, 2023 DW was removed from the list of potential impacts on March 20.)

The hubbub over a space rock that could be as wide as 165 feet (50 meters) highlights a couple of trends to watch for: We’re likely to get more of these asteroid alerts in the years to come, and NASA is likely to devote more attention to heading off potentially dangerous near-Earth objects, or NEOs.

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.