A Universe of New Worlds to Discover & Explore

Exoplanets

In 1992, scientists made one of the most significant discoveries in the history of astronomy; the first confirmed detection of an extrasolar planet. For many decades, it had been widely believed that planets existed around stars other than our own, but it was not until the discovery of two planets orbiting a distant star some 1000 light years away (1 light year = about 6 trillion miles) that their existence was proven beyond doubt. As detection methods advance, particularly thanks to the highly successful Kepler Space Telescope launched in 2009, new alien worlds are being discovered almost every week. Read More →

Searching for Extraterrestrial Microbes

Locating thermophiles in other parts of the universe could very well aid in the search for extraterrestrial life. Most people have agreed that if life is found among the stars, it will be microbial (at least in the near-term future). Many individuals have also suggested that intelligent life forms might very well be extinct in other parts of the universe. If scientists could locate thermophile microbes, they could piece together an archaeological picture of once powerful civilizations.

Taiwan is well known for its hot springs. Most tourists that visit the island end up visiting at least one. Many people like to take relaxing baths in them. Hot springs can be great for people with arthritis. New research is proving that they can also be a great place to find astrobiological data.

Photosynthetic thermophiles that live in hot springs may potentially be removing significant amounts of industrially produced carbon dioxide from the atmosphere. They’ve thrived because of fundamental changes to the atmosphere caused by humanity. In fact, there are some scientists who feel that these microbes could play a vital role in regulating the planet’s climate. That role might become increasingly important in the future.

Planets that were once inhabited by industrially developed civilizations that have since passed might be teeming with life similar to these. If a planet was sufficiently changed by another race of beings, it could have ultimately favored the development of these tiny beings. They could indicate that intelligent lifeforms once inhabited a planet, and that planet could be different today than it was in the past.

While discovering a planet full of microbes would be initially interesting, in the future it could be a relatively common occurrence. Therefore, news services of the future might very well pass by such stories after a few weeks – much like they do today with the discovery of new exoplanets. Finding sufficient numbers of photosynthetic thermophiles would be telling about the history of a world, but it would also require a great deal of geological activity. Then again, there’s nothing to say that other civilizations wouldn’t also have the ability to increase the amount of geological activity on other planets. They might even do it on purpose, as a way of terraforming for instance.

For that matter, humans might want to give that a try. Venus is superheated because of thermal runaway as a result of excess carbon dioxide in the atmosphere. If water were transported to that very hot world, colonists could use the resulting geysers to grow bacteria that would absorb the atmospheric gas.

Reference:
Leu, J., Lin, T., Selvamani, M., Chen, H., Liang, J., & Pan, K. (2012). Characterization of a novel thermophilic cyanobacterial strain from Taian hot springs in Taiwan for high CO2 mitigation and C-phycocyanin extraction Process Biochemistry DOI: 10.1016/j.procbio.2012.09.019

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Future Mission to 51 Pegasi

Due to their proximity to Earth, many of the closest star systems have been extensively studied. When the mass media gets their hands on research, they go wild with it. This is a very human response. Naturally, many individuals want to find proof of extraterrestrial life. Other people want to find places where humanity can expand. Some people might simply have some sort of fantasy fulfilled by being an armchair astronaut.

In 1995 astronomers announced that they had discovered a planet, 51 Pegasi B, in orbit around its star, 51 Pegasi – the first exoplanet found orbiting a star similar to the Sun. If one were to travel 48 light-years from this world, they might happen upon a fifth-magnitude star with a mass that’s almost 47 percent higher than that of Jupiter. The planet in that system orbits extremely close to the stellar body. This might very well suggest that the world could never have supported life.

However, that means very little and long-range planning and missions to these systems should still be planned. Though faster than light travel is still out of reach, even conventional systems could theoretically take an artificial intelligence unit to another star system. While it might take decades to reach another world, the whole of humanity would be better for it – especially if life were discovered.

I’m all for going back to the moon (human exploration). It’s a feasible idea (given that we’ve done it before) and certainly a candidate for early space colonization. That being said, I think we should stop focusing on manned missions to Mars [PDF] for now, and focus instead on sending machines to conduct long-term planetary exploration and discovery missions. Ancestors of today’s scientists will surely reap the benefits of such journeys in the far future as a result of our efforts right now.

Image Credit: BBC

Transit Photometry for Planetary Discovery

Credit: ESA/University of Florida

Transit photometry is a technique astronomers use to detect extrasolar planets. Planetary orbits often force extrasolar bodies to pass between their suns and telescopes on Earth. This causes a drop in the amount of starlight detected by local astronomers. By measuring this drop in light, the relative location of planets can be charted.

Observing the transit pathways that extrasolar bodies take reveals several important pieces of information about them. Size is usually easy to determine from these sorts of studies. Considering that observations can’t be made in person, this might very well be the best way to discover their size.

Studies that take a look at transit photometry data are generally able to calculate the orbital periods of various extrasolar planets. Individuals with an interest in the search for intelligent life might also want to consider what size and orbital have to say about the theoretical habitable zone of another world. Life forms that resemble those found on Earth would most likely be found on planets with similar habitable areas.

Futuristic explorers will quite possibly use the information collected today when trying to select planets for terraforming. Since generational ship missions will need to be carefully planned, collecting accurate data today might save lives tomorrow.

Do I Look Like an Alien to You?

© Scott-Free Productions and 20th Century Fox-Film Corp

I finally got a chance to see Prometheus this weekend and it reminded me why I love both technology and space so much. Without giving too much away for those of you that haven’t yet watched it, one of the more prominent ideas put forth in the movie is that we were created by alien lifeforms that look eerily human in many respects. While I don’t buy into the notion that we were created by other beings (although I do suppose it’s plausible in some respects), I have often wondered what extraterrestrial lifeforms might look like. This is the focus of today’s post. Your input and thoughts are welcome as always.

Occam’s razor would suggest that extraterrestrial lifeforms wouldn’t be quite as different as sci-fi has so often depicted. On the other hand, many scientifically inspired works have long suggested that life on other worlds would be significantly stranger and vastly different than anything found on this planet. For instance, some researchers have depicted alien creatures as somehow silicon-based rather than carbon-based.

© Twentieth Century-Fox

Species with silicon structures could theoretically perform respiration functions with nitrogen molecules instead of oxygen-based matter [all of you biologists out there - feel free to correct me if I'm wrong on this account]. This thinking is perhaps particularly creative, but that doesn’t mean that it’s entirely accurate. Hydrogen, carbon and oxygen molecules are found in certain proportions in life on Earth. In The Fitness of the Environment (1913), American biochemist Lawrence Joseph Henderson first stressed the advantages of carbon and water in lifeforms. Henderson was struck by the fact that the very materials needed for life are exactly those that are abundant here on Earth. It remains a remarkable fact that the atoms most useful for life have very high cosmic relevance. Thus, there’s no reason to suggest that life anywhere else is any different. That doesn’t mean it can’t or hasn’t happened. It just means that right now, we don’t know of another way life may have evolved.

Since the search for extraterrestrial life has often focused around planets that vaguely resemble Earth, it seems a bit strange that people have envisioned aliens as so remarkably foreign. While the culture of some distant planet might be shockingly different, the individual beings there might have much more in common with humanity than anyone ever imagined.

Some researchers have suggested that it seems arrogant to assume the aliens are similar to beings on Earth. However, assuming that otherworldly species resemble Earthlings isn’t necessarily arrogant. One might deduce that it’s the most realistic way to answer the question posed in the title of this post. After all, the idea of lifeforms being based around something besides carbon is seemingly outlandish given our current understanding of biology and how life is created.

What do you think? If there are in fact alien lifeforms out there, are they vastly different from us or closer than those most often depicted in literature and film?

Research:

Ehrenfreund P, Spaans M, & Holm NG (2011). The evolution of organic matter in space. Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, 369 (1936), 538-54 PMID: 21220279

Ziurys LM (2006). The chemistry in circumstellar envelopes of evolved stars: following the origin of the elements to the origin of life. Proceedings of the National Academy of Sciences of the United States of America, 103 (33), 12274-9 PMID: 16894164

Kerr RA (2012). Planetary science. Homegrown organic matter found on Mars, but no life. Science (New York, N.Y.), 336 (6084) PMID: 22628628

Davies PC (2003). Does life’s rapid appearance imply a Martian origin? Astrobiology, 3 (4), 673-9 PMID: 14987473

Frederick Su (1996). Extraterrestrial life forms examined SPIE DOI: 10.1117/2.6199612.0001

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Is a New Form of Life Really So Alien?

The idea of discovering a new form of life has not only excited astronomers and astrobiologists for decades, but also the wider public. The notion that we are the only example of a successful life form in the galaxy has, for many, seemed like an unlikely statistic, as we discover more and more habitable planetary bodies and hear yet more evidence of life’s ability to survive in extreme conditions. A new essay, Read More →

ESA’s Gaia Mission Aim Highs

Yesterday I posted about the important work being conducted on the LSST project. Today I wanted to cover another amazing project – ESA’s Gaia mission.

While many space borne observation platforms have provided excellent images to scientists, these have mostly been in two dimensions thus far. Gaia is a very ambitious mission by the European Space Agency to make a three dimensional map of the Milky Way. While GAIA originally stood for Global Astrometric Interferometer for Astrophysics, it seems that the acronym has been dropped in favor of the shorter name. Read More →

Let’s Explore the Formation & Migration of Planets

Scientists from the University of Cambridge and Universidad Nacional Autónoma de México (UNAM) recently released a paper – Recent Developments in Planet Migration Theory (referenced below) that has some interesting implications for extrasolar planetary studies. I thought a brief discussion of this topic might be beneficial to those of you that are interested in learning more about:

  • How planets and planetary systems are formed
  • Why this is important to our understanding of planet–disc interactions, and the resulting planets’ orbital migration.

How are planets formed?

The most recognized theory in previous centuries was that of the “primordial nebula” – that is a huge gas and dust rotating cloud, from which the Sun and the planets would have formed. Read More →

Life on Europa: A Controversial Proposal on a Moon of Jupiter

An astrobiology research team from the University of Arizona has recently claimed that the ocean below a thick layer of ice on Jupiter’s moon Europa is probably lifeless. The research assumes that the ocean regions under the ice layer of the moon are simply too acidic to support life as we know it. In other words, perhaps life does exist as we don’t know it. Read More →

Let’s Explore Solar System Seismic Activity

Volcanoes: Io (which is slightly larger than the Earth

The U.S. Geological survey estimates that Earth experiences several million earthquakes and around 50 volcanic eruptions every year. But ours is not the only cosmic body that experiences seismic activity: ongoing exploration of the Solar System and the Universe by astronomers and other scientists indicates that volcanic eruptions and quakes (some similar to those on Earth and others vastly different) have been observed on our Moon as well as a growing list of planets, exo-moons, and stars within our galaxy.

The term seismic activity refers to the propagation and movement of elastic waves, called seismic waves, through a planetary body due to perturbations deep beneath its surface or in its upper layers. These waves cause quakes — the shaking and rolling motions that shifts a planet’s upper crust and surface. Quakes can have numerous causes; on Earth, movement of the tectonic plates that make up the planet’s surface, and the molten rock in the mantle beneath it, is the primary cause of earthquakes here at home.

On other bodies within the Solar System including our sun, seismic activity can be caused by other processes as well.  Tidal forces, pressures from cold gases and the roiling of the outer layers of a star can create movements which produce seismic waves, some capable of causing quakes and eruptions many times stronger than those observed on Earth.

The planets of our Solar System can be grouped according to their shared features and distance from the Sun.  The inner planets –Mercury, Venus, Earth and Mars — orbit close to the Sun and are composed primarily of rock, with a solid outer crust.  Beyond Mars, the “gas giants” Jupiter, Saturn, Uranus and Neptune consist largely of hydrogen, ammonia and methane gases around a small, solid core.

Because the inner planets, Earth’s closest neighbors in space, share a hard crust and an originally molten core, all show evidence of volcanic activity. Even tiny Mercury, closest to the Sun, reveals features characteristic of past eruptions.  Photographs and probes of Venus, with its hot cloudy atmosphere, and dry cold Mars also show fault lines, volcanic mountains and ancient lava flows indicating a seismically active past, when planetary cores were hotter and more liquid.

Composed largely of gasses, the outer planets lack a surface crust and a volatile molten core — key features necessary for large-scale planetary seismic activity.  However, in January 2011, advances in asteroseismology (the study of seismic activity on stars) delivered a surprise:  seismic waves were detected on Jupiter, whose composition – liquids and gases around a small rocky core – actually resembles that of the sun.

A variety of factors cause quakes on our moon and others in the Solar System, where evidence of past and present seismic activity has been captured in photographs.  Quakes on our own solitary Moon are caused not by movement of tectonic plates or lava, but by the pull of Earth’s gravity and the expansion of the moon’s cold crust when sunlight returns to its surface after the long lunar night, which lasts 14 Earth days.

Jupiter’s large moon Io experiences extensive seismic activity due to internal friction caused by Jupiter’s gravitational pull. Images of Io, Neptune’s moon Triton and Enceladus, a large moon of Saturn, also reveal evidence of massive cryovolcanic eruptions – explosions caused by pressures of cold or frozen gases beneath the moon’s surface.

Since stars consist primarily of gases, seismic waves observed on stars are believed to originate from turbulence in the outer, convective zone rather than the core. Some of these “star quakes” generate enough energy to cause the entire star to vibrate like a bell. Although our Sun is of course a star, helioseismology (from Greek, Helios: sun), a subspecialty of asteroseismology, focuses on the seismic activity detected there. A solar flare can generate sunquakes, some of which produce energy equivalent to earthquakes of magnitude 11 or stronger.

Beyond the orbit of Neptune, the Kuiper Belt is a region of small icy objects thought to be remnants from the formation of the Solar System. Although Kuiper Belt objects are composed largely of ices such as methane and ammonia, some hints of seismic activity can be observed even there. At 783 miles (1260 km) wide — large enough to have its own name — the Kuiper Belt Object Quaour has an observable surface area containing features suggestive of cryovolcanic changes.

Although conditions on our Earth are ripe for frequent quakes and eruptions, ongoing exploration and observation of the Solar System and the universe beyond reveal that, at least as far as seismic activity is concerned, we truly are not alone in the cosmos.

Image Credit: SOHO/NASA

Reference:

Martínez-Oliveros, J., Moradi, H., Besliu-Ionescu, D., Donea, A., Cally, P., & Lindsey, C. (2007). From Gigahertz to Millihertz: A Multiwavelength Study of the Acoustically Active 14 August 2004 M7.4 Solar Flare Solar Physics, 245 (1), 121-139 DOI: 10.1007/s11207-007-9004-8

A. Grigahcène, M.-A. Dupret, S. G. Sousa, M. J. P. F. G. Monteiro, R. Garrido, R. Scuflaire, & M. Gabriel (2011). Towards precise asteroseismology of solar-like stars Astrophysics and Space Science Proceedings series (ASSP) DOI: arXiv:1112.5961
Sibani, P., & Christiansen, S. (2008). Thermal shifts and intermittent linear response of aging systems Physical Review E, 77 (4) DOI: 10.1103/PhysRevE.77.041106

Sibani, P., & Christiansen, S. (2008). Thermal shifts and intermittent linear response of aging systems Physical Review E, 77 (4) DOI: 10.1103/PhysRevE.77.041106

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