Science World

Science Images of the Week

This solar prominence bowed out and then broke apart  from the sun recently in a graceful, floating style in a little less than four hours. (Image: Solar Dynamics Observatory/NASA)

This solar eruption bowed out and then broke apart from the sun recently in a graceful, floating style in a little less than four hours. (NASA)

A wing-spotted Drosophila elegans - a male fruit fly - courts a female atop a flower. (Image:Nicolas Gompel & Benjamin Prud'homme)

A wing-spotted Drosophila elegans, a male fruit fly, courts a female atop a flower. (Nicolas Gompel & Benjamin Prud’homme)

SpaceX's Dragon space capsule approaching the Internatational Space Station for capture and docking on March 3, 2013. The capsule returned to Earth this past week after a 3 week stay at the ISS. (Photo: NASA)

SpaceX’s Dragon space capsule approaching the International Space Station for capture and docking on March 3, 2013. The capsule returned to Earth this past week after a three-week stay at the ISS. (NASA)

Scientists, using this completed section of the NOvA neutrino detector, have recorded its first three-dimensional images of particles.  The most powerful neutrino detector in the United States is being built for the US Dept. of Energy's Fermilabs in northern Minnesota. (Photo: Fermilab)

The most powerful neutrino detector in the United States, being built for the US Deptartment of Energy in Minnesota, has recorded its first three-dimensional images of particles. (Fermilab)

The European Space Agency's Planck mission released what they called the best map ever of the universe.   (Image: ESA and the Planck Collaboration)

The European Space Agency’s Planck mission released what they called the best map ever of the universe. (ESA and the Planck Collaboration)

Fairy circles - circular patches of barren land - freckle the landscape in the NamibRand Nature Reserve, Namibia. Scientists are thinking they might be the work of sand termites - Psammotermes allocerus.  (Photo: Norbert Juergens)

Fairy circles, round patches of barren land, freckle the landscape at the NamibRand Nature Reserve in Namibia. Scientists think they might be the work of sand termites. (Norbert Juergens)

The planetary nebula known as ESO 456-67 as seen by the Hubble Space Telescope. Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius. (Image: ESA/Hubble & NASA)

The planetary nebula known as ESO 456-67 as seen by the Hubble Space Telescope. Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius. (NASA)

Cassava leaves infected with Cassava brown streak disease (CBSD) at the International Institute for Tropical Africa (IITA) where researchers are learning more about genomics to help breed more effective cassava (tapioca) plants to feed the hungry in their native Africa. (Photo: Teddy Amuge, IITA)

Cassava leaves infected with Cassava brown streak disease (CBSD) at the International Institute of Tropical Agriculture (IITA), where researchers are learning more about genomics to help breed more effective cassava plants that produce tapioca to help feed the hungry in Africa. (Teddy Amuge, IITA)

A crescent moon and NASA's Johnson Space Center’s S-band dish, atop Building 44. (Photo: NASA/Mark Sowa)

A crescent moon and NASA’s Johnson Space Center’s S-band dish, atop Building 44. (NASA)

A view into the south portion of the Overlook crater at Hawaii's Kilauea volcano (Photo: US Geological Survey)

A view into the south portion of the Overlook crater at Hawaii’s Kilauea volcano. (US Geological Survey)

Speed of Light May Not be Constant

Einstein's famous equation (Image: Quatrostein)

Einstein’s famous equation (Image: Quatrostein via Wikimedia Commons)

The speed of light has long been calculated to be 299,792.458 km per second, but now new research from France and Germany indicates that light may not travel at a fixed rate after all, but instead can fluctuate.

A key component of Einstein’s famous E=MC2, the speed of light has been thought to be finite since 1676 after Danish astronomer Ole Rømer first established his findings while studying the motion of Jupiter’s moon Io.

Danish astronomer Ole Rømer circa 1700 (Image: Frederiksborg Museum via Wikimedia Commons)

Danish astronomer Ole Rømer  (Image: Frederiksborg Museum via Wikimedia Commons)

Two separate studies by scientists from the University of Paris-Sud in France and from the Max Planck Institutes for the Physics of Light in Germany are disputing the long established belief concerning the nature of a vacuum.

Researcher Marcel Urban and his colleagues in France said they had identified a “quantum level mechanism” for understanding vacuum.  Urban’s research indicates that a vacuum is not completely empty as long thought, but instead filled with pairs of virtual or ephemeral particles with varying levels of energy.  Because of this, Urban asserts that since the characteristics of a vacuum fluctuate, the speed of light then must also vary as well.

Gerd Leuchs and Luis L. Sánchez-Soto, in their forthcoming paper for the Max Planck Institutes, are suggesting that certain physical constants (physical quantities with values that are thought to be universal in nature and remain unchanged over time) indicate that there are also a number of elementary particles in nature, including those that might be found in a vacuum.  The physical constants they speak of could include properties such as the speed of light and another that’s known as the “impedance of free space” (varying levels of the electric and magnetic fields of electromagnetic radiation traveling through free space).

Albert Einstein circa 1947 (Photo: Library of Congress via Wikimedia Commons)

Albert Einstein (Library of Congress)

Physicists have long found that the concept of the vacuum is one of the most fascinating issues in their field of science.   A vacuum, when viewed at the quantum level – at the smallest and most basic level – is not empty, but instead filled with particle pairs such as electronpositron or quarkantiquark pairs that are constantly appearing and disappearing. While these particle pairs are real particles, their lifetimes are extremely short.

If these findings are proved to be true, they could have an impact on current scientific theories that take the speed of light into consideration.

Both studies will be published in an upcoming edition of the European Physical Journal – D (EPJ-D).

International Apps/Games Competition Ends with Selection of Five Finalists

(Image: UNAOC)

(Image: UNAOC)

The U.N. Alliance of Civilizations recently wrapped up its inaugural international mobile apps and games competition called Create UNAOC Challenge 2012 with the selection of five finalists who were each awarded $5,000 to refine their interactive creations.

Educators, businesses, public service organizations and media outlets have all discovered that creating and offering a variety of computer and smartphone games and applications is a great way to engage and communicate with their audiences as well as providing challenging, but entertaining learning opportunities.

Games and applications designed for computers and platforms such as smartphones and tablets have become tools in providing an effective, yet fun way learning experience. (Photo: Jesse Knish Photography for GDC Online via Flickr/Creative Commons)

(Photo: Jesse Knish Photography for GDC Online via Flickr/Creative Commons)

The UNAOC also saw the growing value and importance of these digital creations.  So last fall, with the help of a number of sponsors, including the Learning Games Network, The Education Arcade, and the Voice of America, issued a challenge to teams and individuals who develop these software packages to come up with creative, educational and engaging games and apps or applications that would also help establish new avenues for intercultural dialogue.

The five finalists developed a variety of mobile apps and games that ranged from those that help players better understand Muslim culture, to the growing crisis regarding the most basic need: water, as well as learning about some of the customs and cultures of countries and regions around the world.

Here are the five finalists in Create UNAOC Challenge 2012 according to the UNAOC website.

(Image: Create UNAOC)

(Image: Create UNAOC)

Ibn Battuta’s App: Developed by MSL Audiovisual & Media, Spain – Players can follow in the footsteps of famed Moroccan scholar and traveler, Ibn Battuta, to learn about the Arab Muslim world.  With this iPad app’s slick artwork, you can follow him on his travels and learn more about Muslim culture. Vivid, animated storytelling and high-quality photos, as well as a desktop version for classrooms, lead you on the digital journey and let you test your knowledge of the Arab world. This app, now available in English and Spanish can be found in the iTunes Store. –Download–

(Image: Create UNAOC)

(Image: Create UNAOC)

Touchable Earth: Developed by Touchable Earth, New Zealand – Explore the sights and cultures of different countries with this interactive world book presented by children from around the world.  With this game, available on the iPad, you can quickly and easily navigate a world map and simply click on an area of the world that you’d like to know more about. Learn about children’s school day, games, music, dress and more in short, high-quality videos. This app is now available in the iTunes Store. Developers add content to it regularly. –Download–

(Image: Create UNAOC)

(Image: Create UNAOC)

Get Water!: Developed by Decode Global, Canada – Take on the role of Maya, a young girl who must collect water for her community in this addictive iPad game that illuminates the global crisis for the most basic and universal need: water. You/Maya are pulled out of school to fetch water for the family. In the style of other smartphone games, you collect water with your bucket and purchase new tools to aid in your effort. Along the way, you learn important facts about water shortages and waste and become a more informed global citizen. This app, still under development, is scheduled to be released very soon.

(Image: Create UNAOC)

(Image: Create UNAOC)

Sanskar: Developed by the Amrita Center for Wireless Networks and Applications, India – Understand different traditions with this interactive game and database that users from around the world can contribute to. Using the Android platform, this app, promotes “harmony through acceptance” and helps you explore new cultures with a magazine-style presentation and animated videos that demonstrate understanding and acceptance in 18 different cultures from around the globe. Each section is followed up with quizzes to assess the amount of materials you covered and measure your newfound respect for the culture. You are also invited to create your own content and share it via the app, to build a database of cultural knowledge.  This app is currently unavailable because it’s still in the early stages of development.

(Image: Create UNAOC)

(Image: Create UNAOC)

Reality: Developed by Alex Gurany, Ruri Lee, Kameron Oser, Danna Ortiz, Lane Pertusi, and Stephen Zhang, United States – This app aims to raise awareness of media bias and promote critical thinking about what we read, see and hear in the media. This winning iPad game puts the player in the shoes of a freelance journalist in a culturally and politically diverse city. By using time and money wisely, as well as talking to the right sources you can put together a complete story and then try to sell that story to one of the city’s newspapers. The rewards are also balanced; increased popularity and money can come at the cost of a more divisive and intolerant society.  This game is currently in development and is not available at this time.

On a recent radio edition of Science World, Michael Suen from the Learning Games Network talked about “Create UNAOC 2012”, the finalists and their winning entries.  Listen below.

[audio://blogs.voanews.com/science-world/files/2013/03/Michael-Suen-Create-UNAOC-2012.mp3|titles=Science World – Michael Suen – Create UNAOC Challenge 2012]

Scientists Confirm Higgs Boson Discovery

The Large Hadron Collider/ATLAS at CERN (Photo: CERN)

The Large Hadron Collider at CERN (CERN)

Scientists working with the world’s largest atom smasher say the mystery particle they found last summer was a Higgs boson, which is believed to give mass to everything in the universe.

However, while the physicists at the European Organization for Nuclear Research (CERN) confirm the particle is a Higgs boson, it doesn’t appear to have all of the properties the theoretical Higgs boson is said to have.

“The preliminary results with the full 2012 data set are magnificent and to me it is clear that we are dealing with a Higgs boson though we still have a long way to go to know what kind of Higgs boson it is,” said Joe Incandela, a spokesperson for CMS, one of the two independent teams behind last year’s discovery.

Physicist Peter Higgs arrives at a seminar, July 4, 2012 at CERN where it was announced that a new subatomic particle, said be consistent with the long-sought Higgs boson, had been discovered. (Photo: AP Photo/Denis Balibouse, Pool)

Peter Higgs at CERN for the July 4, 2012 announcement that a new particle, consistent with  the Higgs boson, which was named for the physicist, had been discovered. (AP)

The teams wound up analyzing two-and-a-half times more data than was available when they announced the particle’s discovery last year.

This week in Italy, both teams reported the new particle is looking more and more like a Higgs boson.

But the scientists still don’t know if the Higgs boson they found was the one predicted by the Standard Model of particle physics, or if it could possibly be the lightest of several bosons which have been predicted in theories that go beyond the Standard Model.

In order to answer that question, the teams say they’ll need more data from the Large Hadron Collider (LHC), the world’s largest and most powerful particle accelerator, as well as more time to study and analyze the existing data.

Another view of a segment of the Large Hadron Collider at CERN. (Photo: AP/CERN)

Another view of a segment of the Large Hadron Collider at CERN. (AP/CERN)

“The beautiful new results represent a huge effort by many dedicated people,” said Dave Charlton, a spokesperson for ATLAS, one of the research teams. “They point to the new particle having the spin-parity of a Higgs boson as in the Standard Model. We are now well started on the measurement program in the Higgs sector.”

The two research teams still need to determine the particle’s  quantum properties as well as how it interacts with other particles.

The data the teams have been working with is generated by CERN’s collider, located along the border of France and Switzerland.   The LHC first went online on September 10, 2008.

New Imager Finds Distant Planets Unlike Others in Known Universe

Image of the HR8799 planets with starlight optically suppressed and data processing conducted to remove residual starlight. The star is at the center of the blackened circle in the image. The four spots indicated with the letters b through e are the planets. (Image: Project 1640)

Image of the HR8799 planets with starlight optically suppressed and data processing conducted to remove residual starlight. The star is at the center of the blackened circle in the image. The four circled spots are the planets. (Project 1640)

Thanks to new technology, astronomers are conducting the first remote reconnaissance of a distant solar system, allowing them to collect the first chemical fingerprints of four exoplanets orbiting a star some 128 light years from Earth.

Astronomers involved with Project 1640, a high-contrast imaging program at the Palomar Observatory in California, say the four exoplanets are radically different from other known worlds.

“These warm, red planets are unlike any other known object in our universe,” said Ben Oppenheimer, Project 1640’s principal investigator. “All four planets have different spectra, and all four are peculiar. The theorists have a lot of work to do now.”

The blinding light of a solar system’s sun usually overpowers views of its surrounding planets, but Project 1640’s innovative observational system sharpened and darkened the light to give scientists a better look at the worlds orbiting a star known as HR 8799.

Demonstration of Project 1640's light control system. Left image is star without new system - Right image is star with filtration that allows objects up to 10 million times fainter than the star to be seen (Images: Project 1640)

Demonstration of Project 1640’s light control system. The left image is a star without new system. The right image is the star with filtration that allows objects up to 10 million times fainter than the star to be seen. (Project 1640)

Because every chemical, such as carbon dioxide, methane, or water, provides a unique light signature, the scientists were able to use a technique called spectroscopy to learn about the chemical makeup of the planets and their atmospheres.  Spectroscopy separates light from an object into its component colors, much in the same way a prism converts sunlight into a rainbow.

The researchers detected an apparent chemical imbalance. Basic chemistry predicts that unless they are in either extremely hot or cold environments, the chemical compounds ammonia and methane should naturally coexist.

The HR 8799 exoplanets all have what the scientists call “lukewarm” temperatures of about 1000 Kelvin (727 degrees Celsius), yet they  show signs of having either methane or ammonia, with very little or no indications of the expected chemical coexistence.

The Project 1640 instrument prior to its installation at the 200-inch Hale Telescope at Palomar Observatory (Photo: Palomar Observatory/S. Kardel)

The Project 1640 instrument prior to its installation at the 200-inch Hale Telescope at Palomar Observatory (Palomar Observatory/S. Kardel)

The researchers  also found signs of other chemical compounds such as acetylene, which until now hasn’t been found on any exoplanet, and that carbon dioxide may be present there as well.

The exoplanets aren’t the only members of their solar system which are displaying odd characteristics. The astronomers noticed its sun, HR 8799, is  quite different from our  sun.

Not only does the star have 1.6 times the mass and five times the brightness of our sun, but its brightness can vary by as much as eight percent over a period of two days, while producing about 1,000 times more ultraviolet light than the sun.

These are factors which could affect the spectral fingerprints of the planets.

The Project 1640 team is already at work collecting more data on this solar system so they can look observe changes in the planets over time.

Rats Communicate Brain to Brain

(Image: Duke University)

( Duke University)

The old proverb, “two heads are better than one,” was put to the test recently when researchers electronically linked the brains of two rats, prompting the animals to work together to accomplish a common goal.

The researchers fitted each rat with a device that allowed one rat to send brain waves to the other, even when separated by long distances.  The rat that received the transmitted information used it to help perform a simple task, which earned both rats a reward.

When the rats’ joint efforts were unsuccessful, the animals used the device as a two-way communicator, to mentally collaborate with each other until they performed the task properly.

“These experiments demonstrated the ability to establish a sophisticated, direct communication linkage between rat brains, and that the decoder brain is working as a pattern-recognition device,” said Miguel Nicolelis from Duke University’s School of Medicine. “So basically, we are creating an organic computer that solves a puzzle.”

Microscopic electrodes were inserted into the brains of the two lab rats, into an area of the cerebral cortex which processes motor information, forming what researchers called an “organic computer.”

One of the rats, considered to be the encoder, transmitted brain wave information to the other rat, known as the decoder.

Screen capture of a video demonstrating behavior of the encoder rat (left) transmitting brain waves to the decoder rat (right) who is receiving the information with an electronic device (Photo: Duke University)

Screen capture of a video showing the encoder rat (left) transmitting brain waves to the decoder rat (right), which is receiving the information via an electronic device (Duke University)

The encoder rat received a visual cue, such as a light, indicating which lever to press in order to be rewarded with a sip of water.

When the encoder rat pressed the correct lever, brain activity indicating its  decision was translated into signals of electrical stimulation and transmitted directly to the brain of the decoder rat.

The encoder rat, unlike his partner, wasn’t given the same kind of visual cue to indicate which lever to press to obtain the reward.

So, in order to get the sip of water, the decoder rat had to rely strictly on the information transmitted by the encoder rat via the brain-to-brain electronic interface.

Researchers found the decoder rat responded to the electronic cues about 70 percent of the time.

The researchers also learned that the brain-to-brain interface provided two-way communications between the two rats which allowed them to help each other.

An encoder rat fitted with a brain-to-brain interface from video capture (Image: Duke University)

An encoder rat fitted with a brain-to-brain interface (Duke University)

“We saw that when the decoder rat committed an error, the encoder basically changed both its brain function and behavior to make it easier for its partner to get it right,” Nicolelis said. “The encoder improved the signal-to-noise ratio of its brain activity that represented the decision, so the signal became cleaner and easier to detect.”

The researchers even took an encoder to Brazil while the decoder rat remained in a North Carolina lab. Despite the distance, scientists were able to send brain wave signals between the rats via the internet and found that they were still able to work together.

“So, even though the animals were on different continents, with the resulting noisy transmission and signal delays, they could still communicate,” said Miguel Pais-Vieira, a postdoctoral fellow and author of the study. “This tells us that it could be possible to create a workable, network of animal brains distributed in many different locations.”

The study with the details of the research and findings were published recently in  Scientific Reports.

Third Radiation Belt Discovered Around Earth

A new radiation belt has been discovered around Earth. It is shown here using actual data as the middle arc of orange and red of the three arcs seen on each side of the Earth. (Image: JHUAPL/LASP)

A new radiation belt has been discovered around Earth. It is shown here using actual data as the middle arc of orange and red of the three arcs seen on each side of the Earth. (Image: JHUAPL/LASP)

NASA scientists have discovered a third radiation belt briefly surrounded Earth for about a month before being blasted away by an interplanetary shock wave from the sun.

Experts had long thought there were only two distinct regions of trapped radiation. But the third ring was spotted by twin Van Allen radiation probes NASA launched in 2012 to study the radiation belts which encircle Earth and can be hazardous to orbiting satellites and astronauts.

“This is the first time we have had such high-resolution instruments look at time, space and energy together in the outer belt,” said Daniel Baker from the University of Colorado in Boulder, who is lead author of the study. “Previous observations of the outer radiation belt only resolved it as a single blurry element. When we turned REPT [the Relativistic Electron Proton Telescope] on just two days after launch, a powerful electron acceleration event was already in progress, and we clearly saw the new belt and new slot between it and the outer belt.”

According to mission scientists, the discovery demonstrates radiation belts are dynamic and flexible in nature, which provides a better understanding of how they respond to solar activity.

However, the discovery might not have occurred had scientists followed standard operating procedures.

An artist rendering depicting the twin Van Allen Probes in orbit within Earth's magnetic field. (Image: JHU/APL)

Artist rendering of the twin Van Allen probes in orbit within Earth’s magnetic field. (Image: JHU/APL)

Anxious and excited mission scientists turned on a critical piece of equipment soon after it was launched into space aboard the probe.  Usually, standard operating procedures for most NASA science missions call for a waiting period that can take months. After that, instruments are slowly turned on and activated one at a time, as technicians slowly ramp them up to full power.

If scientists working with the Van Allen probes mission had followed that set of procedures, the third Van Allen belt might never have been spotted. Data sent back to Earth from the probes throughout the month of September at first showed the two expected Van Allen belts.

But a few days later, the scientists noticed  the belt’s outer ring seemed to be squeezing into an intense, tightly packed band of electrons and that a third, less compact belt of electrons formed further out, creating a total of three rings.

Named after the noted physicist, James Van Allen, the man who discovered them in 1958, the Van Allen radiation belts are two, and now sometimes three, layers of trapped radiation from solar winds or cosmic rays held in place by Earth’s magnetic fields.

Earth’s magnetic fields, which come from our planet’s inner core, repel most harmful radiation away from us, keeping it high above Earth where it accumulates in the Van Allen belts.

Graphic rendering of the Van Allen belts (Image: NASA)

Graphic of the Van Allen belts (NASA)

These layers of radiation are greatly affected by space weather and expand and contract depending upon the amount of energy sent to Earth from the sun and elsewhere.

The Van Allen belts can extend into space from an altitude of about 1,000 to 60,000 kilometers above the Earth’s surface.  The belt closest to Earth is called the inner belt. It’s separated from the outer belt by  an empty region of space.  This gap between the two Van Allen belts is caused by low-frequency radio waves that eject energy particles which would otherwise accumulate there.

Scientists have said there are times, when the sun erupts, that particles force their way into the gap, but soon disappear after a few days.

The Van Allen probes mission includes two spacecraft packed with identical instruments so that simultaneous measurements can be taken from different locations within the radiation belts.

“The fantastic new capabilities and advances in technology in the Van Allen Probes have allowed scientists to see in unprecedented detail how the radiation belts are populated with charged particles and will provide insight on what causes them to change, and how these processes affect the upper reaches of Earth’s atmosphere,” said John Grunsfeld, NASA’s associate administrator for science.


Van Allen Probes Discovery – NASA Video

After Russian Meteor, Keeping Closer Eye on Sky

A meteorite contrail is seen over a vilage of Bolshoe Sidelnikovo 50 km of Chelyabinsk on Friday, Feb. 15, 2013. (Photo: AP/Nadezhda Luchinina, E1.ru)

A meteorite contrail is seen over a village in Russia’s Chelyabinsk region on Friday, Feb. 15, 2013. (AP)

Earth resembled a cosmic shooting gallery this month after a meteor exploded over Russia. And then, a few hours later, an asteroid passed closer to Earth than most weather and communications satellites.

These two events, happening so close to each other, alerted people to the dangers posed by near-Earth objects such as asteroids, comets and other celestial debris lurking in outer space.

Several government agencies worldwide have programs to find and track these potential intruders.

This week, the Canadian Space Agency became the latest member of the international science community to join the effort, launching its NEOSSat spacecraft aboard an Indian PSLV-C20 rocket.

Astronaut Russell L. "Rusty" Schweickart - Circa 1971 (Photo: NASA)

Astronaut Russell L. “Rusty” Schweickart – Circa 1971 (NASA)

Also known as Canada’s Sentinel in the Sky, the experimental microsatellite is designed to detect and track near-Earth objects and space debris.

Other organizations also plan to keep an eye on these threatening space objects.

The B612 Foundation, a private organization comprised of notable scientists, including two former NASA astronauts, hopes to develop an early warning system to alert people to incoming danger.

Founded in 2001, the group originally focused on asteroid deflection research and advocacy. Later it realized that to protect humanity from a potentially destructive impact, an early warning system would be required.  The group went to work developing technology to make that possible.

The group plans to design, build, test, insure and launch a privately-funded spacecraft called the Sentinel Infrared Space Telescope.

Artist illustration of the B612 Foundation's space telescope Sentinal (Image: B612 Foundation)

Artist illustration of the B612 Foundation’s space telescope Sentinal (B612 Foundation)

With its Sentinel spacecraft, the B612 foundation hopes to discover and catalog 90 percent of asteroids, larger than 140 meters, which pass through Earth’s region of the solar system.

The mission team also hopes to document a significant number of smaller asteroids, down to a diameter of 30 meters.

So what if an asteroid or comet is found to be on a collision course with our planet?

Former NASA astronaut, Russell “Rusty” Schweickart (Apollo 9), warns against trying to completely destroy such an object with a nuclear explosion.

Schweickart, one of the founders of the B612 foundation,  favors a deflection technique, which would mean giving the space object a  nudge to veer off of its projected collision path with Earth.

According to Schweickart, in order to deflect a space object, preventative efforts must start several years to a decade ahead of the projected impact with Earth.

This would be done in two stages.  The first involves running the object off with an adequately sized spacecraft.

One method that's been proposed to deflect an asteroid away from a collision course with Earth is a kinetic impactor where a spacecraft rams into the object giving it a nudge and pushing it away.  This is the ESA's proposed Hidalgo space craft may be able to do just that. (Photo: ESA)

A kinetic impactor is a spacecraft that rams into the object giving it a nudge and pushing it away. The ESA is hoping that their proposed Hidalgo space craft will be able to do just that. (ESA)

If you ran into the side of the object facing Earth, according to Schweickart, the object would slow down; hitting it from the opposite direction would speed it up.  That step alone could prevent a possibly catastrophic impact with Earth.

But to ensure that object has been properly and safely nudged away from hitting  Earth, a gravity tractor would need to follow,  according to Schweickart.

A second spacecraft would pull up next to the object and hover either in front of it to speed it up, or behind it to slow it down.  The mutual gravity between the hovering spacecraft and the space object, he says, will pull the object toward the gravity tractor very slightly, but enough to cause a precise change in its orbit, deflecting it away from Earth.

Schweickart believes high-powered nuclear devices should only be considered if the approaching object happens to be enormous, something that occurs once every several million years.

Rather than using the nukes to blow the asteroid-like object to smithereens, Schweickart says the devices should be detonated near it.

This, he says, would make the object extremely hot on one side, boiling off that side which will push it off in the opposite direction, deflecting it away from Earth.