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NASA’s Double Asteroid Redirection Test (DART) spacecraft is designed to be a one hit wonder. It will end its days by crashing into an asteroid at 24,000 kilometres per hour on September 26. Launched from Earth in November 2021, DART is about the size of a bus and was created to test and prove our ability to defend Earth from a dangerous asteroid.

Landing a direct hit on a target from 11 million kilometres away isn’t easy. But while this sounds far, the asteroid was actually selected by NASA because it is relatively close to Earth. This will give engineers the opportunity to test the spacecraft’s ability to operate itself in the final stages before the impact, as it crashes autonomously.

The target asteroid is called Dimorphos, a body 163 metres in diameter that’s orbiting a 780 metre-wide asteroid called Didymos. This “binary asteroid system” was chosen because Dimorphos is in orbit around Didymos, which makes it easier to measure the result of the impact due to the resulting change in its orbit. However, the Dimorphos system does not currently pose any risk to the Earth.

Regardless, NASA is attempting nothing less than a full scale planetary defence experiment to change an asteroid’s path. The technique being used is called “kinetic impact”, which alters the orbit of the asteroid by crashing into it. That’s essentially what is known as a safety shot in snooker, but played on a planetary level between the spacecraft (as the cue ball) and the asteroid.

A tiny deflection could be sufficient to prove that this technique can actually change the path of an asteroid on a collision path with the Earth.

But the DART spacecraft is going to be completely blown apart by the collision because it will have an impact equivalent to about three tonnes of TNT. In comparison, the atomic bomb dropped on Hiroshima was equal to 15,000 tonnes of TNT.

So, with this level destruction and the distance involved, how will we be able to see the crash? Luckily, the DART spacecraft is not travelling alone on its quest, it is carrying LICIACube, a shoebox-size mini spacecraft, known as a cubesat, developed by the Italian Space Agency and aerospace engineering company Argotec. This little companion has recently separated from the DART spacecraft and is now travelling on its own to witness the impact at a safe distance of 55km.

Never before has a cubesat operated around asteroids so this provides new potential ways of exploring space in the future. The impact will also be observed from Earth using telescopes. Combined, these methods will enable scientists to confirm whether the operation has been successful.

It might, however, take weeks for LICIACube to send all images back to Earth. This period will be utterly nerve wracking – waiting for good news from a spacecraft is always an emotional time for an engineer.

What happens next? An investigation team will look at the aftermath of the crash. These scientists will aim to measure the changes in Dimorphos’ motion around Didymos by observing its orbital period. This is the time during which Dimorphos passes in front and behind Didymos, which will happen every 12 hours.

Ground telescopes will aim to capture images of the Dimorphos’ eclipse as this happens. To cause a significant enough deflection, DART must create at least a 73-second orbital period change after impact – visible as changes in the frequencies of the eclipses.

These measurements will ultimately determine how effective “kinetic impact” technology is in deflecting a potentially hazardous asteroid – we simply don’t know yet.

This is because we actually know very little of the asteroids’ composition. The great uncertainty around how strong Dimorphosis is has made designing a bullet spacecraft a truly enormous engineering challenge. Based on ground observation, the Didymos system is suspected to be a rubble-pile made up of lots of different rocks, but its internal structure is unknown.

There are also great uncertainties about the outcome of the impact. Material ejected afterwards will contribute to the effects of the crash, providing an additional force. We don’t know whether a crater will be formed by the impact or if the asteroid itself will suffer major deformation, meaning we can’t be sure how much force the collision will unleash.

Future missions Our exploration of the asteroid system does not end with DART. The European Space Agency is set to launch the Hera mission in 2024, arriving at Didymos in early 2027 to take a close look at the remaining impact effects.

By observing the deformations caused by the DART impact on Dimorphos, the Hera spacecraft will gain a better understanding of its composition and formation. Knowledge of the internal properties of objects such as Didymos and Dimorphos will also help us better understand the danger they might pose to Earth in the event of an impact.

Ultimately, the lessons from this mission will help verify the mechanics of a high-velocity impact. While laboratory experiments and computer models can already help validate scientists’ impact predictions, full-scale experiments in space such as DART are the closest we will get to the whole picture. Finding out as much as we can about asteroids will help us understand what force we need to hit them with to deflect them.

The DART mission has led to worldwide cooperation among scientists hoping to address the global issue of planetary defence and, together with my colleagues on the DART investigation team, we aim to analyse the impact effects. My own focus will be on studying the motion of the material that is ejected from the impact.

The spacecraft impact is scheduled for September 26 at 19:14 Eastern Daylight Time (00:14 British Summer Time on September 27). You can follow the impact on NASA TV.


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Amber Found in Antarctica for the First Time

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Amber Found in Antarctica for the First Time

The discovery of amber in Antarctica has been reported for the first time, as detailed in a recent study published in Antarctic Science. Dr. Johann Klages from the University of Bremen, alongside a team of researchers, uncovered this specimen in sediment cores from the Pine Island trough in West Antarctica. This ancient amber, originating from approximately 83 to 92 million years ago during the mid-Cretaceous period, offers valuable insights into prehistoric environmental conditions near the South Pole.

Unveiling the First Antarctic Amber

The study was published in Antarctic Science journal and reveals that the amber, known as Pine Island amber, was retrieved using the MARUM-MeBo70 drill rig during a 2017 expedition on the RV Polarstern vessel. This mid-Cretaceous resin is considered a significant breakthrough as it suggests that a swampy temperate rainforest, dominated by coniferous trees, thrived in the region during a much warmer period in Earth’s history. According to Dr. Henny Gerschel from the Saxon State Office for the Environment, Agriculture and Geology, the amber likely contains tiny fragments of tree bark, preserved through micro-inclusions. Its solid, translucent quality indicates that it was buried close to the surface, protecting it from thermal degradation.

Insights into Prehistoric Forest Ecosystems

The presence of pathological resin flow within the amber offers clues into the defence mechanisms used by ancient trees against environmental stressors like parasites or wildfires. “This discovery hints at a much richer forest ecosystem near the South Pole during the mid-Cretaceous,” Dr. Klages explained, noting the resin’s defensive chemical and physical properties that protected it from insect attacks and infections.

Reconstructing Ancient Antarctic Environments

The amber’s discovery marks a key step in reconstructing ancient polar climates, supporting the idea that temperate forests once spanned across all continents. Researchers aim to explore further by analysing whether signs of past life are preserved in the amber. This study, beyond unearthing Antarctic amber, opens new opportunities to deepen understanding of Earth’s climatic past and the adaptability of prehistoric ecosystems.

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An Asteroid Burned Up Over California Just Hours After Being Spotted

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An Asteroid Burned Up Over California Just Hours After Being Spotted

An asteroid measuring roughly one metre in diameter impacted Earth’s atmosphere on October 22, 2024, only hours after its initial detection. Discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Hawaii, the object — named 2024 UQ — approached the planet undetected by global impact monitoring systems before disintegrating over the Pacific Ocean off California’s coast. The European Space Agency’s (ESA) Near-Earth Object Coordination Centre later confirmed the event in its November newsletter, reporting that tracking data for the asteroid did not reach monitoring systems until after the impact had already taken place.

Limited Tracking Data Due to Detection Timing

According to ESA’s November newsletter, 2024 UQ had been picked up by ATLAS’ sky-monitoring telescopes. However, the asteroid was only identified as a moving object minutes before it entered Earth’s atmosphere due to its location between two adjacent sky fields in the survey system. This detection delay meant that essential tracking data was delayed and unavailable for impact monitoring centres, which track potential near-Earth object (NEO) threats. Confirmation of the asteroid’s impact was made possible by data from the National Oceanic and Atmospheric Administration’s (NOAA) GOES weather satellites and NASA’s Catalina Sky Survey, which recorded flashes that confirmed the entry of 2024 UQ.

Third Imminent Impact Event in 2024

This incident marked the third imminent impactor event in 2024. In January, a similar object designated as 2024 BX1 burned up over Berlin, while another asteroid, 2024 RW1, exploded above the Philippines in September, with footage of the fireball captured by local observers. These instances underscore the rarity yet growing frequency of small asteroids entering Earth’s atmosphere undetected.

Global Efforts to Monitor Near-Earth Objects

Planetary defence remains a priority as space agencies worldwide develop systems to track potentially hazardous objects. In addition to projects like ATLAS and the Catalina Sky Survey, NASA’s upcoming NEO Surveyor mission aims to use infrared technology to enhance detection capabilities. ESA’s NEO Coordination Centre continues its work on tracking near-Earth objects, while deflection experiments, including NASA’s DART mission in 2022, are also underway to test potential asteroid redirection strategies.

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NASA’s Swift Discovers Twin Black Holes Disturbing Galactic Gas Cloud

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NASA's Swift Discovers Twin Black Holes Disturbing Galactic Gas Cloud

NASA’s Neil Gehrels Swift Observatory has detected a unique signal from two enormous black holes, locked in a cosmic dance that disturbs a dense gas cloud at the centre of a distant galaxy. The phenomenon, known as AT 2021hdr, has sparked considerable interest among astronomers, with researchers observing an unusual cycle of gas disruptions as the black holes orbit one another.

This gas-churning event was first documented in March 2021 by the Zwicky Transient Facility (ZTF) at the Palomar Observatory, California. Led by Dr Lorena Hernández-García, astrophysicist at the Millennium Institute of Astrophysics and the University of Valparaíso in Chile, a study into AT 2021hdr reveals a recurring flare, a pattern that scientists suggest results from the black holes’ gravitational influence on a massive gas cloud. The findings, which appear in the journal Astronomy and Astrophysics, describe how these giant objects tug and heat the gas, triggering light oscillations across different wavelengths.

Uncovering the Source of AT 2021hdr

Located in galaxy 2MASX J21240027+3409114, about 1 billion light-years away in the Cygnus constellation, these black holes together possess a mass 40 million times that of the Sun. Their close proximity—just 16 billion miles apart—produces observable light variations every 130 days. This frequency, scientists predict, could eventually culminate in the black holes’ merger in approximately 70,000 years.

Initially considered a supernova, the recurring nature of these outbursts led astronomers to reevaluate their assumptions. Dr Alejandra Muñoz-Arancibia, a researcher with ALeRCE and the University of Chile, noted that frequent observations over 2022 helped to develop a more precise understanding of this phenomenon. Since November 2022, Swift’s ultraviolet and X-ray observations have aligned with ZTF’s findings in visible light, reinforcing the theory of an orbiting gas cloud undergoing a cyclical disturbance by the black holes’ gravitational forces.

Future Studies and Implications

This discovery offers a unique perspective on supermassive black hole interactions. Continued studies of AT 2021hdr and its host galaxy—currently merging with another—are expected to provide new insights into galactic evolution and black hole behaviour.

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