Kepler and Search for Extrasolar Planets

Recently NASA announced an astounding discovery: The Kepler missions confirmed the first exoplanet orbiting in the habitable zone of a sun-like G-types star. The newly discovered planet Kepler-22b is a little more than double the size of Earth, and it is located 600 light years away. [1] That is a long way to go, but either way, this discovery is a milestone for the Kepler mission and the search for Earthlike planets.

Kepler space observatory launched in 2009 on a mission to scan an area of the Milky Way galaxy between Cygnus and Lyra in search for Earthlike life supporting planets located in habitable zones. [2] The telescope uses the transit method to detect if a planet passes in front of a star and blocks its light for a very short time. So far 2326 possible planet candidates circling over 1000 stars have been detected by Kepler. Of these, 207 have the size of Earth, 680 are much bigger than our planet, 1181 have the size of Neptune, 203 of Jupiter, and 55 are even larger than Jupiter. But more importantly, 48 of them are confirmed to orbit in habitable zones. [3]

Potential life habitats should be abundant in water and carbon, as well as other elements necessary in organic compounds, such as nitrogen. For the water to stay in liquid form, pressure should not be less than 610Pa. Temperature is also crucial: carbon based life can develop in environments with a temperature up to 160°C and down to several tens of degrees bellow 0°C. Habitats can exist either at the surface or below. [4] All these conditions create the so-called habitable zones. The habitable zone is the range of distances from a star within which water occupies large territories and remains in liquid form on the surface of a planet. [5] It is however not enough for a planet to be in the habitable zone to develop life. Volatiles are needed to form an atmosphere. The planet has to have sufficient mass so that the atmosphere could provide pressure for water to stay liquid; it has to be geologically active; its atmosphere should not leak into space. [6]

Some of the planets discovered by Kepler live in a binary system, orbiting two stars (Kepler-16b), some are much larger than Earth (Kepler-11), or much smaller and rocky (Kepler-10b); others live in complex solar systems with more planets (Kepler-18b, c, and d), yet others seem to be almost identical twins of our planet (Kepler-22b). [7] Kepler may be able to confirm that Earth is not that unique after all.

The latest discovery, Kepler-22b has a revolution period of 290 days, it is 2.4 times larger than Earth, and has a temperature of approximately 22°C. [8] It is yet to be discovered if the planet is gaseous or rocky, what is its mass, and if it has an atmosphere or magnetosphere. Since our technology is far from even studying in depth such a planet, let alone to visit it even by robotic missions, the promise of such discoveries is more in terms of revealing that Earthlike planets could have formed in other solar system and therefore could harbor life.

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Notes:

[1] Phillips, Tony.  Kepler Confirms First Planet in Habitable Zone of Sun-like Star. NASA Science News. http://science.nasa.gov/science-news/science-at-nasa/2011/05dec_firstplanet/ (accessed December 12, 2011), para. 1

[2] Ames Research Center. Kepler: Importance of Planet Detection. http://kepler.nasa.gov/Mission/QuickGuide/ (accessed December 12, 2011), para. 1

[3] Phillips, Tony.  Kepler Confirms First Planet in Habitable Zone of Sun-like Star. NASA Science News. http://science.nasa.gov/science-news/science-at-nasa/2011/05dec_firstplanet/ (accessed December 12, 2011), para. 9

[4] Jones, Barrie William. Life in the Solar System and Beyond. Chichester: Praxis Publishing, 2004, 78.

[5] Ibid, 79.

[6] Ibid, 80.

[7] Ames Research Center. Kepler: Discoveries. http://kepler.nasa.gov/Mission/discoveries/ (accessed December 12, 2011), para. 1

[8] Phillips, Tony.  Kepler Confirms First Planet in Habitable Zone of Sun-like Star. NASA Science News. http://science.nasa.gov/science-news/science-at-nasa/2011/05dec_firstplanet/ (accessed December 12, 2011), para. 4.

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References

Ames Research Center. Kepler: Discoveries. http://kepler.nasa.gov/Mission/discoveries/ (accessed December 12, 2011).

Ames Research Center. Kepler: Importance of Planet Detection. http://kepler.nasa.gov/Mission/QuickGuide/ (accessed December 12, 2011).

Jones, Barrie William. Life in the Solar System and Beyond. Chichester: Praxis Publishing, 2004

Phillips, Tony.  Kepler Confirms First Planet in Habitable Zone of Sun-like Star. NASA Science News. http://science.nasa.gov/science-news/science-at-nasa/2011/05dec_firstplanet/ (accessed December 12, 2011).

Image source: NASA/Ames/JPL-Caltech, http://www.nasa.gov/images/content/607691main_Kepler22bArtwork_946-710.jpg

Failures of Robotic Exploration to Mars

Mars is known has a reputation to be the “spacecraft cemetery” because lots of robotic missions to the Red Planet have been lost. Actually, an overwhelming 60 percent (26 of 43) of the probes launched by all space exploration nations to explore Mars have failed. NASA’s results are not far from these either: without taking into consideration the Mars Science Laboratory, which is on the way to Mars and hopefully will succeed, NASA launched 19 missions to the Red Planet, of which seven probes were lost: Mariner 3, Mariner 8, Mars Observer, Mars Climate Orbiter, Mars Polar Lander, and the two Deep Space 2 Probes. [1] What is going on?

Mariner 3, launched in 1964, did not make it to Mars because the shroud on top of the rocket where the probe was located did not open properly, and the solar panels did not open, so the spacecraft ended up orbiting the sun uselessly. [2] Mariner 8 failed during launch in 1971. [3] While the Mars Observer was successfully launched in 1992 and traveled all the way to Mars for 337 days, the contact with the probe was lost in 1993 just when it was about to enter orbit. [4] The Mars Climate Orbiter was launched in 1998 to function as a weather satellite in orbit around Mars, but it was also lost when it arrived to the Red Planet one year later, in 1999. [5] The Mars Polar Lander had as mission to land to the Martian South Pole. Launched in the beginning of 1999 together with the two Deep Space 2 probes, the entire missions with 3 probes on board was lost, again at their arrival to the Red Planet, at the end of 1999. [6]

Is there a Mars curse going on? One reason more probes are lost to Mars than any other celestial body is that more missions were launched to explore the Red Planet than any other body in the solar system. But there is also human error. Such an error occurred during inserting the Mars Climate Orbiter into orbit: because of a navigational error, the satellite occupied an orbit 100 kilometers lower than it was initially intended. The error was performed by NASA’s subcontractors, Lockheed Martin simply because they were not using the standard metric system, which in turn led to serious calculation errors. [7]

It is also important to notice that most failures have occurred in the early years of space exploration, and each of them helped improve the next mission. I would rather give some credit to the Red Planet than blame it for those missions that did not make it, by labeling such results as being a consequence of a Mars curse. It may also seem not to be the right approach to look into failures rather than successes, but I am a firm believer that we learn from the failed missions much more than we learn from the successful ones. Sending robotic explorers to Mars is a complex business, and the recently extremely successful missions to the Red Planet owe a lot to those that did not make it.

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Notes:
[1] National Aeronautics and Space Administration. Mars Exploration Program: Historical Log. http://mars.jpl.nasa.gov/programmissions/missions/log/ (accessed December 5, 2011), p. 1.

[2] NASA. Mars: NASA Explores the Red Planet, Mariner 3 and 4. http://www.nasa.gov/mission_pages/mars/missions/mariner3-4-index.html (accessed December 5, 2011), para. 2.

[3] NASA. Mars: NASA Explores the Red Planet, Mariner 8 and 9. http://www.nasa.gov/mission_pages/mars/missions/mariner8-9-index.html (accessed December 5, 2011), para. 2.

[4] NASA. Mars: NASA Explores the Red Planet. http://www.nasa.gov/mission_pages/mars/missions/index-past.html (accessed December 5, 2011).

[5] Ibid.

[6] Ibid.

[7] O'Neill, Ian. The “Mars Curse”: Why Have So Many Missions Failed? Universe Today, March 22, 2008. http://www.universetoday.com/13267/the-mars-curse-why-have-so-many-missions-failed/ (accessed December 5, 2011), para. 9.

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References

NASA. Mars: NASA Explores the Red Planet. http://www.nasa.gov/mission_pages/mars/missions/index-past.html (accessed December 5, 2011).

NASA. Mars: NASA Explores the Red Planet, Mariner 3 and 4. http://www.nasa.gov/mission_pages/mars/missions/mariner3-4-index.html (accessed December 5, 2011).

NASA. Mars: NASA Explores the Red Planet, Mariner 8 and 9. http://www.nasa.gov/mission_pages/mars/missions/mariner8-9-index.html (accessed December 5, 2011).

National Aeronautics and Space Administration. Mars Exploration Program: Historical Log. http://mars.jpl.nasa.gov/programmissions/missions/log/ (accessed December 5, 2011).

O'Neill, Ian. The “Mars Curse”: Why Have So Many Missions Failed? Universe Today, March 22, 2008. http://www.universetoday.com/13267/the-mars-curse-why-have-so-many-missions-failed/ (accessed December 5, 2011).

Science Fiction - Science Fact

I have never been a science fiction fan, and I am not familiar with many examples. Therefore the ones I have chosen may belong to common knowledge. For a science fiction thing that is already a science fact, I chose man’s trip to the moon, as illustrated by Jules Verne and transformed into a science fact by the Apollo program. For a science fiction thing that is still to become a science fact, but it may sometime soon, I chose extraterrestrial life.

In 1865 Jules Verne published From the Earth to the Moon. In this story, to reach the moon, the characters launch themselves from a canon in a projectile spaceship to land on the Moon. Since the novel does not conclude as to what happened to the characters afterwards, Jules Verne wrote a sequel entitled Around the Moon in which the author continues to follow the unfinished trip to the moon. I believe the idea that man could travel to the moon developed in this book has generated lots of confidence in people that such a thing could become a possibility. After all, Jules Verne’s literature brought some other ideas that later on became reality, such as the submarine in Twenty Thousand Leagues under the Sea, and the helicopter in Robur the Conqueror. A book like From the Earth to the Moon could have had an impact on the eventual development of space travel to the moon. Actually, during the return trip to Earth of Apollo 11, Neil Armstrong said:

"A hundred years ago, Jules Verne wrote a book about a voyage to the Moon. His spaceship, Columbia took off from Florida and landed in the Pacific Ocean after completing a trip to the Moon. It seems appropriate to us to share with you some of the reflections of the crew as the modern-day Columbia completes its rendezvous with the planet Earth and the same Pacific Ocean tomorrow." [1]

The Day the Earth Stood Still is probably one of the very few science fiction stories that captured my interest. At the beginning of this story, an astrobiologist is recruited by the government to participate in a highly classified operation that turns out to be the landing of an extraterrestrial spaceship in the Central Park of New York. I believe we are getting close to discover life elsewhere in the universe. While I am not convinced the reality will occur just like in The Day the Earth Stood Still, as intelligent life seems to be scarce, simple life forms have a good chance to thrive on various other celestial bodies. Earth’s extremophiles have proved that life can develop about anywhere, in any kind of environment. With this knowledge in mind, we will have to design future missions capable to reveal such a possibility. While Curiosity is on the way to forever change our views about the neighbor planet, missions like the Europa Jupiter System Mission seem realistic and possible in the next decade. Such a mission would search Europa’s surface for evidence of fossilized organisms that have been carried up through the cracks and deposited on the surface. This would be sufficient to reveal life on Europa, provided its already discovered liquid ocean has been harboring life for quite while. This seems to be a science fiction scenario about to become science fact, and I sure hope this will happen in my lifetime. 

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Notes:

[1] NASA History. Apollo Flight Journal, Apollo 11, Day 8, part 2: More Television and Stowage for Re-entry. http://history.nasa.gov/ap11fj/25day8-reentry-stowage.htm (accessed November 28, 2011).

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Reference

NASA History. Apollo Flight Journal, Apollo 11, Day 8, part 2: More Television and Stowage for Re-entry. http://history.nasa.gov/ap11fj/25day8-reentry-stowage.htm (accessed November 28, 2011).

Humans and Robots II

I first realized I had an opinion about whether humans or robots should explore space was when the Obama Administration cancelled the Constellation program. I realized then, and no offense to anyone whose job was affected by this decision, that it was appropriate to put the breaks on the human spaceflight program until further progress was made in the field, and that exploring the solar system with probes is the perfect solution for now. Even at that time I was not for exclusive exploration with robots, but rather for using machines in places where humans cannot yet go in preparation for when they will eventually be ready for deep space travel.

The main reason I was completely dedicated the robotic exploration was the outstanding discoveries that our probes have brought in the past two decades. We have learned so much about our neighborhood, and we have discovered for the first time the real vastness of the universe and many of its secrets. While our presence in the solar system is still scarce, with the very few probes that visited Mars, Jupiter and Saturn we came very close to realizing the potential of life all over the place. Just couple of days ago the existence of a liquid water ocean on Europa has been confirmed from the analysis of data sent by Galileo. Not to mention how the Hubble Telescope has completely changed our perspective about the universe. “The greatest explorer today is not even human. It’s the Hubble Space Telescope, which for nearly two decades has offered us all a mind-expanding window to the cosmos”. [1]

But I am a firm believer human should explore space by themselves and not completely rely on robots. “Exploration is inherent to humankind… and it makes us human”. [2] Thirst for knowledge is one of the main characteristics of the species. Space exploration is a process expanding the human knowledge and its range of action. [3] Human space flight has both and immediate and long-term importance. Direct exploration offers closer insights, familiarizing the human species with living in space, and it is likely to provide further survival on other celestial bodies when planet Earth will be no longer suited for human habitation.

Reading chapter 3 in Robots in Space did not really change my ideas, but made me think further about the mid-20^th century when enthusiastic individuals set the foundation of the space age. In the Disney movie Man and the Moon, a whole section is dedicated to Werner von Braun’s fascinating ideas about how man could reach the moon. While watching his presentation I observed myself sliding towards a feeling that this video was recent, and not at all belonging to the fifties. Von Braun’s ideas sounded as if they were taken from Star Trek. I later read in chapter 3 that one reason his fantastic space station could not be accomplished was the discovery of the Van Allen radiation belts. No reason to blame Van Allen for his strong advocacy against human spaceflight after all J But indeed, if I were living in the fifties and watch Von Braun’s presentation I would have not even consider robots. His space station looked more like a building in the city center, having all departments needed to run the show, including gravitation. No wonder such a fantastic idea had a strong impact on the humans vs. robots debate at the beginning of the space age. Who needs robots when humans could live in space just as well as on Earth?

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Notes

[1] Tyson, Neil deGrasse. “Why America Needs to Explore Space”. Parade Magazine. August 5, 2007. http://www.haydenplanetarium.org/tyson/read/2007/08/05/why-america-needs-to-explore-space (accessed November 22, 2011), para. 10.

[2] Dordain, Jean-Jacques. “Space exploration in the 21st Century: Global opportunities and challenges”. http://www.nasa.gov/offices/oce/appel/ask/issues/38/38i_space.html (accessed November 22, 2011), 2.

[3] Ibid, 2.

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References

Dordain, Jean-Jacques. “Space exploration in the 21st Century: Global opportunities and challenges”. NASA Project Management Challenge 9 Feb 2010. http://www.nasa.gov/offices/oce/appel/ask/issues/38/38i_space.html (accessed November 22, 2011)

Tyson, Neil deGrasse. “Why America Needs to Explore Space”. Parade Magazine. August 5, 2007. http://www.haydenplanetarium.org/tyson/read/2007/08/05/why-america-needs-to-explore-space (accessed November 22, 2011).

Image source: http://www.lns.cornell.edu/~seb/celestia/b-vb/images/across_03.jpg

Video Source:  http://www.youtube.com/watch?v=J1urigkMtAw&feature=related

Human & Robotic Spaceflight

While space exploration has been successful both with humans and robots, opinions about whether to continue one, the other, or both are divided. Some people advocate the continuation of human spaceflight, while others consider that robotic exploration will bear fruit in areas where humans cannot go. Such opinions were recently expressed by Michael D. Griffin, NASA administrator, and John Merchant, CEO of the robotics firm RPU Technology.

“I am an unabashed supporter of space exploration in general and of human space flight in particular. I believe that the human space flight program is in the long run possibly the most significant activity in which our nation is engaged. For what, today, do we recall renaissance Spain, King Ferdinand, and Queen Isabella? Unless one is a professional historian, the memory which is evoked is their sponsorship of Columbus in his voyages of discovery. For what, in five hundred years, will our era be recalled? We will never know, but I believe it will be for the Apollo lunar landings if for anything at all. And this is entirely appropriate. Human expansion into space is a continuation of the ancient human imperative to explore, to exploit, to settle new territory when and as it becomes possible to do so. This imperative will surely be satisfied, by others if not by us.” -Michael D. Griffin

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Griffin is a strong believer that human spaceflight is the most “significant activity” people can engage into and the only one that will be remembered a few centuries from now. He compares the Apollo program to the missions of discovery during the Renaissance and underlines that in 500 years from now the future generations will refer to the lunar landings in the same way we refer to Columbus’ landing in America. Griffin believes that humans are prone to explore and if the US will not do it, other people will. [1]

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"Putting more money into human spaceflight is going to be extremely unproductive. ...My position is that we shouldn’t give up on the human exploration of space, but we recognize that you can perform the human exploration of space by telepresence. ... we’ve already sent two rovers to Mars using early-stage telepresence to dig into the surface of Mars to look for signs of water. I very strongly feel that if we devoted a fraction of the resources that we’ve been devoting to manned spaceflight missions to telepresence, we could develop a capability so that humans on Earth could experience and function in a distant space environment like Mars as effectively as if they were actually there." -John Merchant

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By contrast, Merchant underlines that continuing to pay for human spaceflight would be a big loss. His belief is that robotic exploration can do what people do and even more, and therefore allocating at least some of the manned spaceflight funds to the robotic missions would allow exploration in hostile environments as if people were there, while remaining on Earth. Merchant exemplifies his beliefs with the successful mission of the Mars rovers able to explore the planet without humans. [2]

According to Launius and McCurdy, the prospect of NASA is that robots and humans should work together for further exploration of space. [3] This perspective seems to be right because it includes everybody’s opinion and it is a productive solution. While Griffin might remain disturbed that robots will still be sent to explore the solar system, and Merchant would still believe it is a waste of money to continue sending humans in space, continuing exploration with both sustains both military and civil space programs. [4]

One interesting idea brought up by Launius and McCurdy is that at the moment human capabilities still exceed those of the robots, but on the other hand robots are cheaper and if lost during the mission no human life is at risk. [5] From Griffin’s point of view, praising human capabilities in space would go hand in hand with his idea of human spaceflight as a necessity if we would like to be remembered by the future generation. In the same time, for Merchant, the fact that machines are cheaper and human risk-free would be just the right concept underlining his belief that robots deserve some of the human spaceflight’s funds so that they can do more than people.

One of the reasons for such different opinions may lay in the fact that individuals engaged in the humans vs. robots debates consider the two to be completely different things with separate visions. The idea advocated by Launius and McCurdy that humans and machines are not “separate entities” may come as a surprise for both Griffin and Merchant. Humans and robots do the same kind of work, while complementing each other rather than taking each other’s place. [6] Having both may be the best solution. While Griffin’s reaction to these arguments may still gravitated around finances and the waste of money invested in human space flight, Merchant’s reaction may also be that robots can do better in places where humans cannot go. Either way, the idea that Griffin and Merchant could pick from Robots in Space is that having humans or robots explorers does not need to be a debate, but rather cooperation.

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Notes:

[1] SpaceRef. Prepared Statement of Dr. Michael D. Griffin: "The Future of Human Space Flight". October 16, 2003. http://www.spaceref.com/news/viewsr.html?pid=10683 (Accessed November 8, 2011), para. 3.

[2] Berger, Eric. The case for sending robots, not humans, to Mars. August 19, 2009. http://blog.chron.com/sciguy/2009/08/the-case-for-sending-robots-not-humans-to-mars/ (Accessed November 8, 2011), para. 4-5.

[3] Launius, Roger D. and Howard E. McCurdy. Robots in Space. Baltimore: Johns Hopkins University Press, 2008, 27.

[4] Ibid, 27.

[5] Ibid, 3.

[6] Ibid, 30.

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References

Berger, Eric. The case for sending robots, not humans, to Mars. August 19, 2009. http://blog.chron.com/sciguy/2009/08/the-case-for-sending-robots-not-humans-to-mars/ (Accessed November 8, 2011).

Launius, Roger D. and Howard E. McCurdy. Robots in Space. Baltimore: Johns Hopkins University Press, 2008.

SpaceRef. Prepared Statement of Dr. Michael D. Griffin: "The Future of Human Space Flight". October 16, 2003. http://www.spaceref.com/news/viewsr.html?pid=10683 (Accessed November 8, 2011).

Image source: http://www.airspacemag.com/space-exploration/Humans_vs_Robots.html