Featured Research

from universities, journals, and other organizations

Intercepting asteroids to avoid Armageddon

October 23, 2013
Potential asteroid impact on Earth can have disastrous consequences. In order to prevent such collisions, earthbound space objects must be deflected. This could be accomplished using a space probe to impact the asteroid.

Illustration of an asteroid approaching Earth.
Credit: NASA

Potential asteroid impact on Earth can have disastrous consequences. In order to prevent such collisions, earthbound space objects must be deflected. This can be accomplished using a space probe to impact the asteroid.

65 million years ago, Earth was ravaged by tsunamis, a huge dust cloud darkened the skies and acid rain fell on plants and animals. These events marked the latest mass extinction and the creeping end for more than 50 percent of all species on Earth. Not even the dinosaurs would survive this apocalypse. These events were most likely caused by an asteroid approximately 10 kilometers across that impacted Earth in the area of today's Gulf of Mexico, scarring the planet's surface with a crater over 170 kilometers wide. Is this scenario unthinkable today? To date, astronomers have identified almost 10,000 asteroids with an orbit that approaches or crosses Earths' orbit -- and the number is growing. Last February, a meteorite injured almost 1500 people when it exploded over the Russian city of Chelyabinsk, with a population of over a million. At a diameter of some 20 meters, the meteorite had a weight of 10,000 tons.

The objects that Frank Schäfer of the Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI in Freiburg deals with are much larger than this. His research is focused on medium-size objects measuring between 100 and 300 meters in length. An asteroid of this size could potentially wipe out entire cities or regions. The scientists have conducted initial laboratory experiments to verify the possibility of deflecting asteroids by impacting them with heavy masses at high speeds -- for instance large space probes. The principle behind the impact is similar to a game of billiards: when one ball hits another, the second changes course. "During impact, not only does the probe transfer its own momentum to the asteroid, there is also the recoil of detached material from the crater, which is ejected against the direction of the impact," describes Schäfer with regard to one of the key test findings. "This recoil effect acts like a turbocharger on the deviation of the asteroid." Tests show that, due to this effect, the overall momentum transferred to the asteroid is up to four times greater than that of the probe alone.

Speeds of up to 10 km/s

To study this more closely, researchers attach various materials with asteroid-like properties -- dense quartzite, porous sandstone or airy concrete -- to a pendulum and impact them with small aluminum projectiles. What they discovered was that the more porous the asteroid is, the less momentum is transferred. In other words, the projectile approach is particularly effective for denser space objects. The projectiles reach speeds of up to 10 km/s in the laboratory, which means they can attain the impact speeds that researchers are aiming for in future missions. In order to demonstrate the transfer of momentum and the associated efficiency of the impact, the researchers use high-speed cameras and laser interferometers to measure the pendulum's swing."In actual fact, the impact of a space probe would change the speed of the asteroid by just a few centimeters per second. But that's enough to deflect its course to a significant degree over a longer period. So if we want to stop an asteroid on collision course with the Earth from hitting us, we'll need to fire at it many years ahead of time," explains Schäfer.

The pendulum test is part of the NEOShield space project, which is funded by the EU and coordinated by Alan Harris of the German Aerospace Center's (DLR) Institute of Planetary Research. It brings specialists from Germany, France, the United Kingdom, Spain, the United States and Russia together to work on ways to protect our planet from near-Earth objects, which are asteroids whose orbit brings them into our proximity. One of the project's aims is to plan a space mission by mid-2015 to actually deflect an asteroid. There won't be a shortage of objects for the specialists to choose from: according to NASA, there will be over 20 close approaches in September alone. Of these, object "2008 HB38" will come closest to us on the 15th at just under five million kilometers.

Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.

Cite This Page:

Fraunhofer-Gesellschaft. "Intercepting asteroids to avoid Armageddon." ScienceDaily. ScienceDaily, 23 October 2013. <www.sciencedaily.com/releases/2013/10/131023090720.htm>.
Fraunhofer-Gesellschaft. (2013, October 23). Intercepting asteroids to avoid Armageddon. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2013/10/131023090720.htm
Fraunhofer-Gesellschaft. "Intercepting asteroids to avoid Armageddon." ScienceDaily. www.sciencedaily.com/releases/2013/10/131023090720.htm (accessed July 22, 2014).

Share This

More Space & Time News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) — Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) — Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
Powered by NewsLook.com
45 Years Later, Buzz Aldrin on Walking on Moon

45 Years Later, Buzz Aldrin on Walking on Moon

AP (July 18, 2014) — Forty-five years ago Sunday, Apollo 11's Neil Armstrong and Buzz Aldrin became the first humans to set foot on the moon. Speaking at the Intrepid Sea, Air & Space Museum, Aldrin described what he was thinking right before the historic walk. (July 18) Video provided by AP
Powered by NewsLook.com
Orbital Cargo Ship Reaches International Space Station

Orbital Cargo Ship Reaches International Space Station

AFP (July 16, 2014) — Orbital Sciences Corporation's unmanned cargo ship arrived Wednesday at the International Space Station carrying a load of food and equipment for the six-man crew at the research outpost. Duration: 00:33 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins