Asteroids Archives

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 30, 2023February 3, 2023 by Laurence Tognetti

The Outer Solar System Supplied a Surprising Amount of Earth’s Water

Currently exploring the Kuiper Belt, New Horizons is just one of five spacecraft to reach beyond 50 astronomical units, on its way out of the solar system and, eventually, into interstellar space. (Credit: NASA/Johns Hopkins APL/Southwest Research Institute)

In a recent study published in Science, a team of researchers at Imperial College London examined 18 meteorites containing the volatile element zinc to help determine their origin, as it has been long hypothesized that Earth’s volatiles materials, including water, were derived from asteroids closer to our home planet. However, their results potentially indicate a much different origin story.

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.

December 13, 2022December 13, 2022 by Evan Gough

Asteroids Didn’t Create the Moon’s Largest Craters. Left-Over Planetesimals Did

The largest impact basin on the Moon is the South-Pole Aitken basin. It, and other impact basins, were created by planetesimals according to a new study. Image Credit: Moriarty et al., 2021.

The Moon’s pock-marked surface tells the story of its history. It’s marked by over 9,000 impact craters, according to the International Astronomical Union (IAU.) The largest ones are called impact basins, not craters. According to a new study, asteroids didn’t create the basins; leftover planetesimals did.

November 16, 2022November 16, 2022 by Matt Williams

What Would Asteroid Mining do to the World's Economy?

Artist's impression of an astronaut conducting an EVA with an asteroid. Credit: NASA

About a decade ago, the prospect of “asteroid mining” saw a massive surge in interest. This was due largely to the rise of the commercial space sector and the belief that harvesting resources from space would soon become a reality. What had been the stuff of science fiction and futurist predictions was now being talked about seriously in the business sector, with many claiming that the future of resource exploitation and manufacturing lay in space. Since then, there’s been a bit of a cooling off as these hopes failed to materialize in the expected timeframe.

Nevertheless, there is little doubt that a human presence in space will entail harvesting resources from Near Earth Asteroids (NEAs) and beyond. In a recent paper, a team of researchers from the University of Nottingham in Ningbo, China, examined the potential impact of asteroid mining on the global economy. Based on their detailed assessment that includes market forces, environmental impact, asteroid and mineral type, and the scale of mining, they show how asteroid mining can be done in a way that is consistent with the Outer Space Treaty (i.e., for the benefit of all humanity).

November 4, 2022November 4, 2022 by Evan Gough

Three New Potentially Hazardous Asteroids Discovered, Including a big one That Measures 1.5 km Across

Recently, Astronomers spotted three near-Earth asteroids (NEAs) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years. Could we use space lasers to protect Earth from these hazards? Image Credit: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

An asteroid 1.5 km across is no joke. Even a much smaller one, about the size of a house, can explode with more power than the first nuclear weapons. When an asteroid is greater than 1 km in diameter, astronomers call them “planet-killers.” The impact energy released from a planet-killer striking Earth would be devastating, so knowing where these asteroids are and where they’re headed is critically important.

Our defensive capability against asteroid strikes is in its infancy, so advance notice of asteroids that could cross Earth’s orbit is critical. We’ll need time to prepare.

November 2, 2022November 2, 2022 by Andy Tomaswick

When an Asteroid Gets Close to Earth, we get a Rare Opportunity to Learn What it’s Made of

Gravity calculations can provide plenty of insight into a variety of phenomena. Everything from Einstein rings to the rocket equation is at least partially dependent on gravity. Now an undergraduate student and professor team from MIT think they have a new use for gravity calculations – understanding the interior density of asteroids.

October 17, 2022October 17, 2022 by Nancy Atkinson

Arecibo Won’t Be Rebuilt

Damage to the 305-meter telescope at Arecibo Observatory, after its collapse on Dec. 1, 2020. The remains of the instrument platform are visible on the telescope’s dish. Credit: NSF.

The National Science Foundation announced last week that it won’t rebuild or replace the iconic Arecibo Observatory in Puerto Rico, which collapsed in 2020. Instead, the NSF says they have solicited calls for proposals to build a multidisciplinary educational center at the site.

Additionally, the plans do not appear to allow for any future science or observing from the other facilities at the Arecibo site, as the NSF said they will not provide any “operational support for current scientific infrastructure, such as the 12-meter radio telescope or Lidar facility,” also on location.

The announcement has been met with disappointment and disbelief.

October 11, 2022October 7, 2024 by Alan Boyle

Success! DART Impact Shortened Asteroid’s Orbit Time by 32 Minutes

Debris from asteroid targeted by DART — A Hubble Space Telescope image from Oct. 8 shows the debris blasted from the surface of an asteroid called Dimorphos 12 days after it was struck by NASA's DART spacecraft. (Credit: NASA / ESA / STScI / Hubble)

NASA says its DART spacecraft caused a larger-than-expected change in the path of its target asteroid when they collided two weeks ago — marking a significant milestone in the effort to protect our planet from killer space rocks.

Ten months after it was launched, the Double Asteroid Redirection Test’s refrigerator-sized robotic probe crashed into a 560-foot-wide asteroid called Dimorphos on Sept. 26, as it circled a bigger asteroid known as Didymos. The paired asteroids were 7 million miles from Earth at the time, and posed no threat to Earth before or after the smashup.

Before the crash, DART’s science team said they expected the collision to reduce the time it took for Dimorphos to go around Didymos by about 10 minutes. NASA would have regarded any change in excess of 73 seconds as a success.

After the crash, detailed observations from ground-based observatories showed that the orbit was actually 32 minutes shorter — going from 11 hours and 55 minutes to 11 hours and 23 minutes. That’s three times as much of a change as scientists were expecting. Scientists also said Dimorphos appears to be slightly closer to Didymos.

“This is a watershed moment for planetary defense, and a watershed moment for humanity,” NASA Administrator Bill Nelson said today. “All of us have a responsibility to protect our home planet. After all, it’s the only one we have.”

October 3, 2022October 3, 2022 by Evan Gough

Scientists Have Been Underestimating the Asteroid That Created the Biggest Known Crater on Earth

South Africa's Vredefort Crater is Earth's largest impact crater. New Research clarifies the power of the impact and its catastrophic effects. Image Credit: NASA Earth Observatory image by Lauren Dauphin / University of Rochester illustration by Julia Joshpe

Ancient impacts played a powerful role in Earth’s complex history. On other Solar System bodies like the Moon or Mercury, the impact history is preserved on their surfaces because there’s nothing to erase it. But Earth’s geologic activity has erased the evidence of impact craters over time, with some help from erosion.

Earth’s complex history has elevated its status among its Solar System siblings and created a world that’s rippling with life. Ancient giant impacts have played a role in that history, bringing catastrophe and disruption and irrevocably changing the course of events. Deciphering the role these giant impacts played is difficult since the evidence is missing or severely degraded. So how do scientists approach this problem?

One crater at a time.