Why Study Astrophysics?

The study of our universe

Cosmology – The study of our universe

I am often asked why I am so obsessed with studying astronomy, astrophysics, cosmology etc. which serves no practical purpose to anyone. The people who ask such questions entertain the notion that anything that does not give immediate monetary benefit is not worth pursuing. In this article I will try as much as possible to highlight the benefits of pursuing pure science such as astrophysics. I will be using the words astronomy and astrophysics interchangeably as differentiating the two is not the main aim here.

Astrophysics to me is an eternal subject. The study of our universe will continue as long as the universe exists and therefore the subject of astronomy will stay on for trillions of years into the future (or at least till any intelligent species can make the study.)  We exist because the universe exists and that makes the study of our universe the most important of all subjects in my opinion.

A person who does not have any training in astrophysics or for someone who thinks he or she is too “practical” may not be convinced with this answer. For such people, any subject should have the potential of generating immediate revenue. In their point of view, the trendiest subjects that have a career potential in the market are the ones people should be pursuing. That point of view is not essentially wrong. However, these so called trendy subjects are like soap bubbles. They form and then get destroyed after a period of time. People pursuing them always run a risk because if the subject of their choice goes down in popularity, they are forced to learn the next trending subject in the job market.

Space science as a subject does not suffer from this problem. It has lived on ever since the dawn of human civilization and is bound to continue into the foreseeable future. Besides, making money in my opinion should not be our pursuit as a race of intelligent beings. Our world is slowly moving towards a non-monetary one and thus our real pursuit should be the attainment of knowledge and its applications.

Astrophysics - A pure science

Astrophysics – A pure science

As I said, astrophysics is a pure science. If you ask any astrophysicist as to whether a particular theory found by him or her has an immediate application in daily life, he or she may say that there aren’t any. However, the same thing can be told about many other subjects. I have added some references that will tell you about many subjects that fall into the category of being “useless” to the “practical” folks but are still pursued by thousands. Hence, it is not something that one must criticize astronomy with. No subject is useless. In the hand of the right person, the scope of any subject is limitless.

If you are willing to delve deep enough, you will know that astronomy is actually a field with a lot of practical applications. Of course the applications come indirectly and eventually but the impact is profound. Astronomy is a frontier research field. In order to do any kind of research in it, you need cutting edge technology. The study of astronomy thus pushes the limits of our current technology thereby contributing to the development of new and innovative methods in terms of instruments, processes and software to get things done. Therefore, pushing research in astronomy will push research in other fields when these technologies are used in the broader sense.

The benefits of astronomy comes from technology transfer i.e. by transferring the technology that was originally invented for astronomy into various applications in the industry. Some areas where we can see the fruits of research in astronomy are optics, electronics, advanced computing, communication satellites, solar panels and MRI Scanners.  Even though it takes time before an application of a research in astrophysics finds its way into our daily life, the impact it eventually makes is worth the wait. Astronomy also has revolutionized our way of thinking by constantly giving us new ideas throughout history.

Let’s now look at a few examples where the research in space sciences and technology is helping humans around the world:

Medicine

MRI Scanner

MRI Scanner

Perhaps the most important application of astronomy for us would be its technology transfer to medicine. Both astronomy and medicine requires us to see objects with ever more precision and resolution in order be accurate and detailed in our analysis. The most notable among the applications is the method of aperture synthesis. It was developed by the radio astronomer Martin Ryle of the Royal Swedish Academy of Sciences. His technology is now used in Computerized Tomography which is commonly called CT scan. It is also used in Magnetic Resonance Imaging or MRI and Positron Emission Tomography or PET in addition to other imaging methods.

The Cambridge Automatic Plate Measuring Facility has collaborated with a drug company whereby blood samples from leukemia patients can be analyzed much faster. This helps in better accuracy in medication.  The method that is now used for non-invasive way to detect tumors was originally developed by radio astronomers. It helped increase the true-positive detection rate of breast cancer to 96%.

The heating control systems of neonatology units, i.e. units for newborn babies were initially developed as small thermal sensors to control telescope instrument. The low energy X-ray scanner used for outpatient surgery, sports injuries etc. was developed by NASA. It is also used by the Food and Drug Administration of USA to study the contamination in pills. The software that is used for processing satellite pictures is also helping medical researches to do wide scale screening of Alzheimer’s disease.

The Earth System

Asteroid 2011 MD

Asteroid 2011 MD

Our planet is under the constant influence of the Sun and our climate depends on it greatly. Studying the dynamics of the sun and other stars thus help us have a better understanding of Earth’s climate and its effects. Studying the solar system, especially asteroids tell us about the potential threats that they pose to the Earth. We do not want to be wiped out like the dinosaurs and studying potentially hazardous objects give us insights into how we can protect ourselves in time of a catastrophe. Even the recent passage of the asteroid 2011 MD dangerously close to Earth is a reminder that we should accelerate development of technologies to prevent an impact. Missions to asteroids also give us opportunities to test our technologies in future space exploration and also give insights into subjects such as geology.  It is also important to do space exploration as part of our long term exploitation of space based resources.

Industry

Charge Coupled Device

Charge Coupled Device

In industry, there are many technology transfers that can be cited. For instance, the Kodak Technical Pan was a film originally developed to use in solar astronomy to record the changes on the surface structure of the Sun. It is now used by industrial photographers, medical and industrial spectroscopy specialists and industrial artists. Until recently, the Technical Pan was also used to detect diseased crops and forests, in dentistry and medical diagnosis. It was also used for probing layers of paintings to check for forgery.

The Charge Coupled Devices or CCDs were first used in astronomy in 1976 as sensors for astronomical image capture. This Nobel Prize winning discovery not only replaced film in telescopes but also in personal cameras and mobile phones.

IDL or Interactive Data Language is used for data analysis in astronomy. It is now also used by companies such as General Motors to analyze data from car crashes. This means that astronomy is contributing to research in vehicle safety.

IRAF or Image Reduction and Analysis Facility is a collection of software written by the National Optical Astronomy Observatory. It is used by AT&T to analyze computer systems and to do graphics in solid-state physics.

Communication

GPS - Global Positioning System

GPS – Global Positioning System

Radio astronomy has given birth to excellent communication tools, devices and data processing methods. For example, the computer language FORTH was first developed in order to be used at the Kitt Peak Telescope. The founders of the language also created the company named Forth Inc. and the language is now being used widely by FedEx for their tracking services.

The satellites of Global Positioning System rely on distant astronomical objects such as quasars and other distant galaxies to determine accurate positions. So, next time you use GPS, remember the stars.

The most common everyday communication application of astronomy would be Wireless Local Area Network or WLAN. Astronomer John O’Sullivan in 1977 came up with a method to sharpen images from a radio telescope. It was later found to be useful in strengthening radio signals in computer networks thereby giving birth to WLAN.

Aerospace and Defense

Aerospace and Defense

Aerospace and Defense

Astronomy and the aerospace industry share many technologies that include telescope instrumentation, imaging and processing techniques for images. A defense satellite is basically a telescope that is pointed towards earth and thus use very identical technology and hardware to that of astronomy. The methods used to differentiate between rocket plumes and cosmic objects in stellar atmosphere models are similar as well. They are studied for use in early warning systems.

A device called solar-blind photon counter was once invented by astronomers to measure particles of light from a source without being overwhelmed by the particles from the Sun during the day. It is now used to detect the ultraviolet photons coming from the exhaust of a missile thereby aiding in UV missile warning system. It can also be used to detect toxic gases.

Energy Sector

Solar Panels - A source of clean energy

Solar Panels – A source of clean energy

The techniques developed to detect gravitational radiation produced by massive bodies in acceleration is used to determine the gravitational stability of underground oil reserves. That is a fantastic application in the energy industry.

The methods in astronomy can also be used for finding new fossil fuels in addition to evaluating the possibility of new renewable sources. Companies such as Texco and BP use IDL to do analysis of core samples around the oil fields. The graphic composite material that was initially developed for an orbiting telescope array is now being used by Ingenero in their solar radiation collectors.

The technology used in X-Ray telescopes to image X-Rays is now being researched for plasma fusion. If successful, it would lead to a boom in clean energy in future.

Education and International Collaboration

Astronomy in Schools

Astronomy in Schools

Astronomy is a great tool to stimulate young minds. If you want children to pursue careers in science and technology, astronomy can help a lot. It engages the minds of kids and helps them keep up to date with the happenings in the scientific world. This therefore affects not just astronomy but other subjects as well. Modern science is a more collaborative effort. And astronomy has been instrumental in bringing together many countries to collaborate on projects that require telescopes and other instruments located at multiple points in the world. Researchers travel around the world to work on these facilities. This brings in many other advantages such as cultural transfer as well.

From the examples I mentioned and countless other examples that you can find online, it is pretty clear that the study of the universe is very beneficial to humanity. There are many people around the world who are interested in the study of the universe but are thwarted by the pseudo-pragmatic folks who think the subject is useless. My suggestion to anyone who wishes to study the subject would be to not let others tell you how practical or impractical that subject is. If they do not like what you are doing, it is their problem, not yours. Half the people who advice you against the subject do not really know anything about its breadth and depth.

The Sextant - An ancient celestial navigation tool

The Sextant – An ancient celestial navigation tool

As mentioned before, astronomy changes the way we think and look at this world. Even before writing was invented, humans have looked up at the sky to make decisions regarding when to plan the crops, how to keep track of the days and months or how to navigate the seas. Some of the greatest quests of human kind would not have been possible if methods to study the skies weren’t invented. Where we came from and where we are going are deep philosophical questions that are yet to be answered. In my opinion, studying the cosmos using rigorous science is the only way to finally know the answer.

Before I end, I must thank astronomers Marissa Rosenberg and Pedro Russo and all the other eminent people whose insightful articles I have referred to create this write-up. I have added them as reference for anyone who wishes to read more about the advantages of investing their time and effort in studying astronomy, astrophysics, cosmology and related areas, which are considered pure science without any immediate practical value by many.

My father often quotes the old saying, “People will come and go, but the institution remains.” I would like to rephrase that and say, “People who oppose the study of our universe will come and go. But the universe will remain.

Bibliography

  • Aperture synthesis. (2014, Apr 22). Retrieved from Wikipedia: https://en.wikipedia.org/wiki/Aperture_synthesis
  • Astronomy and the Modern World. (2011, Feb 17). Retrieved from Canadian Astronomy: http://www.castor2.ca/07_News/headline_110310.htmlz
  • Astrophysics. (2014, Apr 22). Retrieved from Wikipedia: https://en.wikipedia.org/wiki/Astrophysics
  • CASU Astronomical Data Centre. (2001, Feb 1). Retrieved from Cambridge Astronomy Survey Unit: http://casu.ast.cam.ac.uk/surveys-projects/adc
  • Gallagher, B. (2013, Apr 11). The 10 Most Worthless College Majors. Retrieved from Complex City Guide: http://www.complex.com/city-guide/2013/04/10-most-worthless-college-majors/
  • Hall, S. (2013, Nov 11). How Astronomy Benefits Society and Humankind. Retrieved from Universe Today: http://www.universetoday.com/106302/how-astronomy-benefits-society-and-humankind/
  • Loose, T. (2012, Jan 12). College Majors That Are Useless. Retrieved from Yahoo Education: http://education.yahoo.net/articles/most_useless_degrees.htm
  • Odenwald, S. (2001, Feb 1). Why is astronomy important in our lives? Retrieved from Astronomy Cafe: http://www.astronomycafe.net/qadir/q1138.html
  • Rosenberg, M., Russo, P., Bladen, G., & Christensen, L. L. (2013). Astronomy in Everyday Life. Retrieved from International Astronomical Union: https://www.iau.org/public/themes/why_is_astronomy_important/
  • Rosenberg, M., Russo, P., Bladen, G., & Christensen, L. L. (2013, Nov 3). Why is Astronomy Important? Retrieved from Cornell University Library: http://arxiv.org/abs/1311.0508
  • Why is astronomy important? (2004, Aug 3). Retrieved from Clearly Explained: http://clearlyexplained.com/technology/science/astronomy/why-is-astronomy-important.html

Extraterrestrial Resources and Humans – Can Space Resources Save Our Civilization?

Abstract

Image of Biosphere

Current global resource utilization depends on a closely-knit economy, society and environment. However, effective limits exist on the biosphere’s capability to absorb pollutants while providing resources and services (Adams). This paper describes why in the light of issues in sustainability of Earth’s resources and growing human population it is imperative to expand utilization to extraterrestrial resources to save our civilization.

The Necessity

Image of Global Power Consumption

Challenges to resource sustainability arise from a combination of population increase in developing nations and unsustainable consumption in their developed counterparts (Cohen). Estimated global population might peak at 2070 with 9 to 10 billion people, and gradually decrease to 8.4 billion by 2100 (Lutz).

The average power consumption in developed nations is ~ 2 kW per person whereas in the rest of the world, it is ~0.3kW per person. The total production of power globally is ~1.9 billion kW. Based on (Lutz), if the population reaches 10 billion people by 2070, and if the living standards of the world approach current western standards, 20 billion kW would be required. This argument leads to the following possibilities:

  1. Much of the world might remain in lower living standards or
  2. New sources of energy could be discovered

Research in planetary and asteroid geology, spectral and photometric analysis have proposed many celestial bodies as objects harboring useful resources with nearly 50% of them containing volatile substances such as clays, hydrated salts and hydrocarbons (Sonter). The following are some examples of in-situ resources:

  1. Volatiles from comet core, C-type asteroids and Phobos or Deimos
  2. Metals from C-type and M-type asteroids, Moon and Mars
  3. Platinum group metals (PGMs) from C-type asteroids
  4. Energy through abundant sunlight
  5. LOX and LH2 from lunar polar ice, lunar regolith, and C-type asteroids
  6. CH4/O2 propellant and inert gases from Martian atmosphere
  7. 3He from the Moon and atmospheres of outer planets
  8. Water and oxygen from Lunar poles, Mars and C-type asteroids

For Apollo-like missions, a limited use of local planetary resources on Moon and asteroids for rocket propellant manufacture would suffice. However, for a permanent, expanding, and self-sustaining extra-terrestrial colony, clever usage of planetary resources is necessary.

The Benefits

The cost of space activities reduce dramatically with offsets in carrying propellants from Earth’s surface to LEO and beyond (Cutler). Thus, commercial mining opportunities in space could provide low cost alternatives as resources on Earth become depleted or unusable.

The following are some of the possible profitable uses of space resources:

  1. Earth orbital operations architectures
  2. Solar power satellites or lunar power systems to beam energy to Earth
  3. Space industrialization for products manufactured in space for people on Earth
  4. Human outposts using silicon solar cells and radiation shielding
  5. Water and precious metals like Pt, Pd and Ir metals for use on Earth, space, life support
  6. 4He from the lunar surface for fusion energy
  7. Propellant production for return trips to Earth

The Challenges

There are economic and technical requirements that a celestial body must satisfy to qualify as a potential ore-body in a mining engineering context (Sonter):

  1. Sufficient spectral data confirming presence of required resources
  2. Orbital parameters that give reasonable accessibility and mission duration
  3. Feasible mining, processing and retrieval concepts
  4. A positive economic Net Present Value

Scientists and mining experts are currently conducting research and analysis on planetary extraction methods based on the above-mentioned considerations. However, this type of resource utilization is still not operational because:

  1. The cost is exorbitant in transporting items into space (about $4400 to $6600 per kilogram). Hence, bases on Moon, Mars, asteroids etc. should procure their necessities like water, oxygen and fuel from in situ resources (Zaburunov).
  2. Even if mission crew finds these items in situ, extraction is still an issue.

Image of ISRU

Different processes involved in mining of extra terrestrial resources offer different levels of complexity:

  1. Martian propellant production requires pumping CO2, splitting it to retain the O2 and producing CH4 (Zubrin)
  2. Lunar polar water for return trips and space propellant depots require excavating cold trap regolith, extracting water thermally and electrolysis, and liquefaction to produce propellant (Alexander)
  3. Photovoltaic cells produced from lunar materials require Si extraction from lunar regolith, recovering reagents, and manufacture of arrays (Freundlich)

The need for a market in any type of development and management of resources is very important. The potential short term and mid term markets of space resources, include:

  1. Propellant for Mars sample return missions
  2. Propellant for LEO missions such as Orbital Express
  3. Energy and propellant for human lunar and Martian activities

The long-term markets of space resources include:

  • Energy for Earth through solar power and 3He fusion
  • Raw material to support lunar and Mars outposts
  • Support for space industrialization and space tourism
  • Counter Arguments

    Contrary to using space resources, recycle existing resources is easier to accomplish and comparatively cheap. However, considering issues like runaway greenhouse effect, population growth, self-sufficiency and long-term human presence (Stancati) in space, it is better to colonize space and utilize space resources. In addition, repeated missions to same ore-bodies (Sonter) predict requirements of higher internal rate of return with heavy discounts on sale receipts and “off-optimum” characteristics compared to the first mission or to a different target. Finally, mine operator’s interest in refurbishing or upgrading equipment and non-competitiveness of return missions from trajectory synodic considerations counteract the idea.

    Conclusion

    Earth’s resources being finite as a closed system, energy and materials from outer space being clean and available for millions of years, the solution to the growing human population and resource and energy crisis is utilizing space resources to meet the demands. Space resources have the potential to ensure survival and good living standards for human species and as these resources become more available with better technology, the value of space economy will improve (Komerath).

    Bibliography

    1. Adams, W.M. “The Future of Sustainability: Re-thinking Environment and Development in the Twenty-first Century.” IUCN Renowned Thinkers Meeting. Zurich: IUCN, 2006. 2-5.
    2. Alexander, R., Bechtel, R., Chen, T., Cormier, T., Kalaver, S., Kirtas, M., Lewe, J., Marcus, L., Marshall, D., Medlin, M., McIntire, J., Nelson, D., Remolina, D., Scott, A., Weglian, J. “Moon-based Advanced Reusable Transportation Architecture.” 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference And Exhibit. Salt Lake City, Utah: Georgia Institute of Technology, 2001. 4-6.
    3. Cohen, J.E. Human Population: The Next Half Century. London: Island Press, 2006.
    4. Cutler, A.H. “Aluminum-Fueled Rockets for Space Transportation System.” McKay, M.F., McKay, D.S., Duke, M.B. Space Resources – Energy, Power and Transport. Washington D.C.: National Aeronautics and Space Administration Scientific and Technical Information Program, 1992. 110.
    5. Freundlich, A., Ignatiev, A., Horton, C., Duke, M., Curreri, P., Sibille, L. “Manufacture of Solar Cells on the Moon.” 31st IEEE Photovoltaic Specialists Conference. Orlando, Florida: Conference Record of the IEEE Photovoltaic Specialists Conference, 2005. 794-797.
    6. Komerath, N.M., Rangedera, T., and Nally, J. “Space-Based Economy Valuation, Analysis, and Refinement.” American Institute of Aeronautics and Astronautics. San Jose, 2006. 1-3.
    7. Lutz, W., Sanderson,W.C. and Scherbov, S. The End of World Population Growth in the 21st Century: New Challenges for Human Capital Formation and Sustainable Development. London: Earthscan, 2004.
    8. Sonter, M.J. “The Technical and Economic Feasibility of Mining the Near-Earth Asteroids.” Acta Astronautica (1997): 637-47.
    9. Stancati, M.L., Jacobs, M.K., Cole, K.J., Collins, J.T. In-situ Propellant Production : Alternatives for Mars Exploration. Washington D.C.: National Aeronautics and Space Administration National Technical Information Center, 1991. 7.
    10. Zaburunov, S.A. “Mines in Space: What is NASA doing?” E&MJ – Engineering & Mining Journal (1990): 16K-16N.
    11. Zubrin, R., Baker, D.A., and Gwynne, O. “Mars Direct: A Simple, Robust, and Cost Effective Architecture for the Space Exploration Initiative.” 29th Aerospace Sciences Meeting. Reno, Nevada: AIAA 91-0326, 1991. 11-14.

    Deflecting an asteroid impact – The Technical Feasibility

    Asteroid Deflection Strategy

    Asteroid deflection strategies have been a topic of interest for those enamoured with space studies for ages galore. From NASA scientists to ordinary people they’ve garnered everyone’s attention. Simply defined, asteroid deflection strategies are the “planetary defense” methods[ref]http://en.wikipedia.org/wiki/Asteroid-impact_avoidance[/ref] using which these near-earth objects (NEOs) are diverted thereby preventing catastrophic occurrences on earth, ranging from tsunamis to impact winters (by placing large quantities of dust into the stratosphere, blocking sunlight)[ref]http://en.wikipedia.org/wiki/Asteroid-impact_avoidance[/ref]. While the probability of such an event occurring any time soon is deemed scant, certain recent events such as Shoemaker-Levy 9 have created enough headlines to get people wondering.

    Spotting an incoming asteroid

    About 90% of NEOs greater than 1 kilometer in diameter have been surveyed by NASA. On a scale of 1 to 10, a 1 kilometer diameter asteroid is deemed to be the least destructive while a 10 kilometer diameter asteroid is considered catastrophic enough to extinguish all life on earth. These survey programs funded by the NASA have been christened “Spaceguard”. Their aim is to attempt to detect and document all asteroids including and exceeding 140 meters in diameter by 2028.

    Deflection strategies

    Nuclear attack

    Asteroid Nuclear Deflection

    This is often considered the easiest and quickest method. This can be done in one of two ways. A nuclear explosion can be instituted around, on or beneath the surface of an asteroid with the resulting blast evaporating part of the object and throwing it off course. This is a form of nuclear pulse propulsion[ref]http://en.wikipedia.org/wiki/Asteroid-impact_avoidance[/ref]. However, one can never be certain whether the NEO has been broken into small enough pieces to completely avoid harm. Fracturing a 10 kilometer asteroid into a six kilometer and four kilometer asteroid is great, but they might still be on target for our lovely little planet and carry worldwide devastation in tow[ref]http://io9.com/5861790/how-to-deflect-an-asteroid-attack[/ref]. An alternative method is to have a series of small bombs explode alongside the asteroid but at a distance enough to not fracture the object. The relatively small forces from any number of nuclear blasts could be enough to alter the object’s trajectory enough to avoid an impact[ref]http://en.wikipedia.org/wiki/Asteroid-impact_avoidance[/ref]. A key factor however is to do so well in advance so as to have the maximum impact.

    Kinetic energy effect

    Asteroid Deflection Kinetic Energy

    This works through the impact of a gigantic, non-explosive object, such as a spacecraft or another NEO, a collision with which to alter the course of the asteroid. This strategy is being pioneered by the European Space Agency using a carrier craft and an impactor that can be released on command.

    Using a gravitational tractor

    Asteroid Deflection Gravitational Tractor

    Proposed by Edward T. Lu and Stanely G. Love, this method involves altering the natural course of an asteroid slowly over a period of time sometimes spanning years. The idea is to have a gigantic heavy unmanned spacecraft hover over an asteroid and divert it from its orbit through the simple mechanics of gravitational attraction. The spacecraft would attract the asteroid towards itself and thus deflect it from its original path. While slow, this method has the advantage of working irrespective of the asteroid composition or spin rate – rubble pile asteroids would be difficult or impossible to deflect by means of nuclear detonations while a pushing device would be hard or inefficient to mount on a fast rotating asteroid[ref]http://en.wikipedia.org/wiki/Asteroid-impact_avoidance[/ref].

    Attach a rocket

    Based upon a proposal of theoreticians at Johns Hopkins University, attaching a rocket to an asteroid would propel it off of its path enough to avoid an impact with earth. Another method is termed the Madmen approach, in which a series of disassembles are docked on to the asteroid which then use the asteroid to create small pebbles which are ejected away from the asteroid. The presumed advantage is that it would take only weeks or months to reduce asteroid mass and velocity using this method and it would act as a safe alternative to chemical and nuclear explosives.

    Conclusion

    It would be safe to say that it would be in humanity’s interest for several countries to have contingency plans and alternative methods ready in the unlikely event of an asteroid attack occurring anytime soon. Russia has some nascent plans in store while the European Space Agency plans to test its kinetic energy method on a non-threatening asteroid in 2015. In addition, NASA’s constant documenting of NEOs along with the search for effective deflection strategies should let us sleep easy at night.

    Apophis! – Earth’s death knell?

    Image of Apophis
    Image of Apophis as a snake in Egyptian Mythology

    Egyptian mythology has a character called Apophis which was an ancient spirit of evil and destruction, a demon determined to plunge our world into eternal darkness. Astronomers reason that the name befits a menace that is currently hurling towards Earth from outer space.

    Scientists for the past few years have been monitoring a 390 metre wide asteroid which is currently classified under the “Potentially Hazardous Objects” category because of its calculated collision course with the planet. Governments have already been alerted to take necessary actions to avoid any catastrophe that might arise if this rock collides with our planet.

    According to an estimate by NASA, an impact from Apophis, which is scheduled to take place on April 13 2036, would generate over 100,000 times the energy released in the nuclear blast over Hiroshima. Thousands of square kilometres from the impact site would receive the direct effect of the impact and the rest of the earth will see the effects of huge amounts of dust released into the atmosphere.

    Image of 99942 Apophis
    99942 Apophis – Courtesy Wikipedia

    Scientists insist on every Near Earth Objects meetings that there is very little time left to decide and act since the technology required to thwart an asteroid would take decades to design, test and build.  Meteorite experts say that it is a question of when and not if such an object will collide with Earth. A meteorite of the size of 1 km and above will cause mass extinction to species inhabiting our planet including us. The possibility of such collisions is in every hundred million years and it seems we are already overdue for a big collision.

    Apophis has been a concern since December 2004 after astronomers projected the orbit of the asteroid into the future and found that the odds of it hitting the Earth is alarming. It was predicted that if it missed Earth in its first approach to Earth in 2029, then the next approach in 2036 might most certainly end in a collision. The object currently has an Aphelion of 1.0987 AU, Perihelion of 0.74604 AU, Semi-major axis of 0.92241 AU, Eccentricity of 0.19121 and Orbital period of 323.58 d or 0.89 a. It has an Average orbital speed of    30.728 km/s, Mean anomaly of 339.94°, Inclination of 3.3315°, Longitude of ascending node of 204.43° and Argument of perihelion of 126.42°.

    Image of Radar Image of Apophis
    2005 Arecibo Radar Image of Apophis – Courtesy NASA

    Currently Apophis is placed at 4 out of 10 in the Torino Scale which measures the threat posed by an NEO where 10 is a certain collision that causes global catastrophe marking it the highest for any asteroid in recorded history. However, the collision in 2029 was eventually ruled out as more data poured in.

    Astronomer Alan Fitzsimmons of Queen’s University, Belfast said that Earth’s gravity will deflect the asteroid on 2029 and that there is a small possibility of the asteroid moving through a region in space called the keyhole. If that happens, the chances of a collision during its next pass in 2036 will be even higher.

    There is no shortage of ideas as to how to deflect asteroids like these. Even dangerous technologies like nuclear powered spacecraft is under consideration. The Advanced Concepts Team at the European Space Agency is leading the effort in designing a range of satellites and rockets to nudge these potentially hazardous objects. According to Prof Fitzsimmons, the advantage of nuclear propulsion is the amount of power it generates though it has not been tested so far. Solar electric propulsion, another promising idea is already being used by several spacecrafts giving us hope that projects like these would work.

    Another interesting method favoured by ESA is the proposed Don Quijote mission which intends to send two spacecrafts at the asteroid. One of them called Hidalgo is supposed to collide with the asteroid and the other called Sancho is supposed to measure the deflection caused by the collision. The test launch is supposed to take place in 2013. Another idea is to use explosives on the asteroid but no astronomer has so far supported the idea since if the explosion takes place close to impact, we might have several fragments hitting us than one thereby increasing the area of damage.

    Image of Apophis Path of Risk
    The path of risk where Apophis may impact in 2036 – Courtesy Wikipedia

    Currently we cannot rule out the possibility of the 2036 impact. However, we need to get our next chance in making an observation of this object which unfortunately will not come until 2013 when we can use radar observations and work out possible future orbits of this asteroid more accurately. NASA argues that the final decision of what needs to be done has to be made at that stage.

    Astronomers like Fitzsimmons and Yates say that the preparation should start before 2013 itself. In 2029, we will know for sure whether the object will hit us or not. However, if the worst case scenario turns out to be true and if Earth is not prepared, then it will be too late. Hence we cannot wait until 2029 and start preparing now itself.