Connect with us

Published

on

In a world first, NASA has crashed a spacecraft into an asteroid in an attempt to push the rocky traveler off its trajectory. The Double Asteroid Redirection Test – or DART – is meant to test one potential approach that could prevent an asteroid from colliding with Earth. David Barnhart is a professor of astronautics at the University of Southern California and director of the Space Engineering Research Center there. He watched NASA’s live stream of the successful mission and explains what is known so far.

1. What do the images show?

The first images, taken by a camera aboard DART, show the double asteroid system of Didymos – about 2,500 feet (780 meters) in diameter – being orbited by the smaller asteroid Dimorphos that is about 525 feet (160 meters) long.

As the targeting algorithm on DART locked onto Dimorphos, the craft adjusted its flight and began heading towards the smaller of the two asteroids. The image taken at 11 seconds before impact and 42 miles (68 kilometers) from Dimorphos shows the asteroid centered in the camera’s field of view. This meant that the targeting algorithm was fairly accurate and the craft would collide right at the center of Dimorphos.

The second-to-last image, taken two seconds before impact shows the rocky surface of Dimorphos, including small shadows. These shadows are interesting because they suggest that the camera aboard the DART spacecraft was seeing Dimorphos directly on but the Sun was at an angle relative to the camera. They imply the DART spacecraft was centred on its trajectory to impact Dimorphos at the moment, but it’s also possible the asteroid was slowly rotating relative to the camera.

The final photo, taken one second before impact, only shows the top slice of an image but this is incredibly exciting. The fact that NASA received only a part of the image implies that the shutter took the picture but DART, traveling at around 14,000 miles per hour (22,500 kilometers per hour) was unable to transmit the complete image before impact.

2. What was supposed to happen?

The point of the DART mission was to test whether it is possible to deflect an asteroid with a kinetic impact – by crashing something into it. NASA used the analogy of a golf cart hitting the side of an Egyptian pyramid to convey the relative difference in size between tiny DART and Dimorphos, the smaller of the two asteroids. Prior to the test, Dimorphos orbited Didymos in roughly 16 hours. NASA expects the impact to shorten Dimorphos’ orbit by about 1 percent or roughly 10 minutes. Though small, if done far enough away from Earth, a nudge like this could potentially deflect a future asteroid headed towards Earth just enough to prevent an impact.

3. What do we know already?

The last bits of data that came from the DART spacecraft right before impact show that it was on course. The fact that the images stopped transmitting after the target point was reached can only mean that the impact was a success.

While there is likely a lot of information to be learned from the images taken by DART, the world will have to wait to learn whether the deflection was also a success. Fifteen days before the impact, DART released a small satellite with a camera that was designed to document the entire impact. The small satellite’s sensors should have taken images and collected information, but given that it doesn’t have a large antenna onboard, the images will be transmitted slowly back to Earth, one by one, over the coming weeks.

4. What does the test mean for planetary defense?

I believe this test was a great proof-of-concept for many technologies that the US government has invested in over the years. And importantly, it proves that it is possible to send a craft to intercept with a minuscule target millions of miles away from Earth. From that standpoint DART has been a great success.

Over the course of the next months and years, researchers will learn just how much deflection the impact caused – and most importantly, whether this type of kinetic impact can actually move a celestial object ever so slightly at a great enough distance to prevent a future asteroid from threatening Earth.


Affiliate links may be automatically generated – see our ethics statement for details.

Continue Reading

Science

NASA Astronaut Sunita Williams Refutes Health Concerns Amid ISS Mission

Published

on

By

NASA Astronaut Sunita Williams Refutes Health Concerns Amid ISS Mission

NASA astronaut Sunita Williams has recently addressed speculations surrounding her health condition while on the International Space Station (ISS), discarding recent claims made by media outlets regarding her wellbeing. In response to reports that suggested she appeared “gaunt” due to an extended stay on the ISS, Williams clarified her status during a video interview on November 12, explaining that her weight has remained unchanged since her arrival in orbit.

Routine Exercise and Physical Adaptations

Williams, who commands Expedition 72 aboard the ISS, responded to health concerns publicly, indicating that any changes in her physical appearance are the result of rigorous exercise routines rather than health deterioration. Like all astronauts on extended missions, she has been following an intense workout regimen designed to counteract the muscle and bone density loss commonly associated with prolonged microgravity exposure. Williams stated that her routine includes running on a treadmill, riding an exercise bike and lifting weights. It is a form of exercise that has led to increased muscle mass, particularly in her thighs and glutes, while her overall weight remains consistent.

NASA’s Statement on Crew Health

NASA had previously denied the reports, emphasising that Williams and her fellow crew members, including NASA astronaut Butch Wilmore, are in good health. Williams and Wilmore, who arrived at the ISS on June 6 aboard Boeing’s Starliner capsule, were initially scheduled for a ten-day mission under the Crew Flight Test programme. Technical issues with Starliner’s thrusters led NASA to extend their stay on the ISS until early 2025, when they are expected to return with SpaceX’s Crew-9 mission astronauts.

Current ISS Crew Status

The current ISS team, led by Williams, includes three NASA astronauts and three Russian cosmonauts, all working collaboratively despite recent media scrutiny. Williams assured viewers that her health and morale remain robust as the crew carries out essential research and maintenance tasks on the orbiting laboratory showing NASA’s confidence in their well-being during extended missions.

Continue Reading

Science

Math reveals secrets to gaining height on a half-pipe

Published

on

By

Math reveals secrets to gaining height on a half-pipe

A recent study reveals how skateboarders can use mathematical insights to increase their speed and height on half-pipes. Florian Kogelbauer, a mathematician from ETH Zurich, and his research team have examined how specific movements impact a skateboarder’s performance on U-shaped ramps. By alternating between crouching and standing in certain areas, skaters can generate extra momentum, leading to higher jumps and faster speeds. This research, published in Physical Review Research, could lead to more efficient techniques for skaters aiming to improve their skills.

Modelling Momentum on Half-Pipes

The research was published in American Physical Society Journal. The technique of “pumping,” or alternating between crouching and standing, is essential for building speed on half-pipes. Kogelbauer’s team created a model to show how the body’s centre of mass affects movement on a ramp, much like the mechanics of a swing. In their calculations, they found that crouching while moving downhill and standing while moving uphill helps skaters gain height more effectively. This rhythm, the team suggests, could help skaters reach higher elevations on the ramp in fewer motions.

Testing the Theory with Real Skaters

To test the model’s validity, researchers observed two skateboarders as they navigated a half-pipe. They were asked to reach a specific height as quickly as possible. Video analysis revealed that the more experienced skater naturally followed the model’s suggested pattern, reaching the target height with fewer motions. The less experienced skater, who did not follow the pattern as precisely, required more time to reach the same height. This contrast suggests that experienced skaters intuitively apply these principles for better performance.

Broader Applications Beyond Skateboarding

According to Sorina Lupu, an engineer at the California Institute of Technology, this simplified model may also have applications in robotics. By demonstrating how minimal adjustments in body position can impact speed and height, this study offers insights that could make robotic movement more efficient. For engineers, this research indicates that straightforward models of human movement could be used to enhance robotic performance, providing an alternative to complex machine-learning models often used in robotics.

Continue Reading

Science

Global Fossil CO2 Emissions Hit Record in 2024

Published

on

By

Global Fossil CO2 Emissions Hit Record in 2024

Global carbon emissions from fossil fuel combustion have reached an unprecedented peak in 2024, with the Global Carbon Project reporting a projected 37.4 billion tonnes of fossil CO2 emissions, a 0.8% increase from 2023. The report underscores an urgent call for emissions reduction as the world’s annual output of CO2 from fossil fuels and land-use changes collectively approaches 41.6 billion tonnes. Despite increased efforts to mitigate climate impacts, there are no clear signs of a peak in global fossil CO2 emissions, heightening the risk of surpassing critical climate thresholds.

Sector-Specific Emissions and Regional Insights

As per a report by University of Exeter, emissions from fossil fuels, including coal, oil, and gas, are anticipated to rise in 2024, accounting for 41 percent, 32 percent, and 21 percent of fossil CO2 emissions, respectively. Coal emissions are expected to increase by 0.2 percent, oil by 0.9 percent, and natural gas by 2.4 percent. On a regional level, China, responsible for 32 percent of global emissions, is projected to see a slight increase of 0.2 percent, while emissions in the United States are expected to fall by 0.6 percent.

The European Union’s emissions are forecasted to decrease by 3.8 percent, whereas India, contributing 8 percent of global emissions, is projected to experience a 4.6 percent rise. Emissions from aviation and shipping sectors are also set to increase by 7.8 percent this year, though they remain below pre-pandemic levels.

Carbon Budget and Climate Warnings

According to Professor Pierre Friedlingstein from the University of Exeter, who led the study, the absence of a peak in fossil CO2 emissions further reduces the remaining carbon budget needed to keep warming below the Paris Agreement’s 1.5-degree Celsius target. At the current emission rate, a 50 percent probability exists of surpassing this threshold within the next six years. Meanwhile, Professor Corinne Le Quéré of the University of East Anglia acknowledged ongoing efforts in renewable energy deployment and reduced deforestation but stressed that substantial emissions reductions are still essential.

Urgency for Accelerated Action

The report emphasises that while some nations demonstrate progress in emissions reduction, these efforts have not been sufficient to reverse the overall global trend. Dr Glen Peters from the CICERO Center for International Climate Research noted that global climate action remains “a collective challenge,” with gradual declines in emissions in certain regions counterbalanced by increases elsewhere.

Continue Reading

Trending