
Artist’s impression of ESA’s Hera mission on Didymos and Dimorphos. ESA/Science Office.
Perth, Australia:
NASA’s DART mission – Double Asteroid Redirection Test – was humanity’s first real-world planetary defense mission.
In September 2022, the DART spacecraft collided with the “Moon”, a small asteroid companion 11 million kilometers from Earth. One goal was to find out if we could. Pushing such things If someone were to walk our way.
By collecting a lot of data after approach and impact, we’ll also get a better idea of what we’ll be in for if such an asteroid hits Earth.
Five new studies Published in Nature Communications. Today uses images sent back from DART and its travel buddy. LICIACube Unraveling the origin of the Didymos-Dimorphos binary asteroid system. They also put this data in the context of other planets.
DART’s last complete image of Dimorphos, about 12 km from the asteroid and 2 seconds before impact.NASA/Johns Hopkins APLAsteroids are natural hazards.
Our solar system is full of tiny asteroids — debris that never made it into the planets. Those that come close to Earth’s orbit around the Sun are called Near Earth Objects (NEOs). They are the biggest threat to us, but also the most accessible.
Defending planets against these natural threats really depends on knowing their composition—not just what they’re made of, but how they’re put together. Are they solid objects that will punch through our atmosphere if given the chance, or are they? Like piles of rubblebarely held together?
Asteroid Didymos, and its small moon Dimorphos, are part of what is known as a binary asteroid system. They were perfect targets for the DART mission, as the effects of the impact could easily be measured in changes in Dimorphos’ orbit.
They are also near(ish) Earths, or at least NEOs. And it’s a very common type of asteroid that we haven’t seen very well before. Also got the chance to learn how binary asteroids form on the cake.
Quite a few binary asteroid systems have been discovered, but planetary scientists don’t know exactly how they form. In one of the new studies, a team Led by Oliver Barnoin used DART and LICIACube images to estimate the age of the system by looking at surface roughness and crater records from Johns Hopkins University in the United States.
They found that Didymos is about 12.5 million years old, while its moon Dimorphos formed less than 300,000 years ago. This may still seem like a lot, but it’s much smaller than expected.
A pile of stones
Dimorphos is also not solid rock as we commonly imagine. It is a pile of stone rubble barely held together. Along with its young age, this suggests that collisions with large asteroids may have resulted in multiple “generations” of these debris-laden asteroids.
Sunlight actually causes this. Small bodies like asteroids to orbit. As Didymos began to spin like a peak, his figure sank and emerged in the middle. It was sufficient to remove the larger pieces from the main body only, With the omission of some tracks.
These fragments gradually formed a ring of debris around Didymos. Over time, as the debris began to stick together, it formed the small moon Dimorphos.
How could the orbit of Didymos have produced its small moon Dimorphos? Yun Zhang’s video.
Another study, Under the leadership of Maurizio Pajola Auburn University in the US used the Boulder distribution to confirm this. The team also discovered that other non-binary asteroids contain significantly more massive rocks (up to five times larger) than humans have seen.
Another new research Shows us that the rocks on all the asteroid space missions so far (Atokawa, Ryugu and Benno) were shaped the same way. But this excess of massive rocks on the Didymos system may be a unique feature of binaries.
Image taken by Didymos.Bigot, Lombardo et al., (2024)/DRACO/DART (NASA)
Finally, Shows another paper This type of asteroid appears to be more susceptible to cracking. This is caused by a heating–cooling cycle between day and night: similar to the freeze–thaw cycle but without water.
This means that if something (like a spacecraft) were to impact it, a lot of debris would be thrown into space. It will even increase the amount of “cheats” he has. But there’s a good chance that what’s underneath is much stronger than what we’re seeing on the surface.
This is where the European Space Agency The Diamond Mission It will not only be able to provide high-resolution images of Dart impact sites, but will also be able to probe the asteroid’s interior using low-frequency radar.
The DART mission not only tested our ability to protect ourselves from future asteroid impacts, but also shed light on the formation and evolution of near-Earth debris piles and binary asteroids.
(the author:Eleanor K. SansomResearch Associate, Curtin University)
(Disclosure statement: Eleanor K. Sansom receives funding from the International Center for Radio Astronomy Research and is supported by the Australian Research Council)
This article has been republished. Conversation Under Creative Commons License. read Original article.
(Other than the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
(Tags translation
Source link