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Considering Our Cosmic Home: Reflections from the 2012 Venus Transit
| by | Branyon May, Ph.D. |
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| Time lapse image of the 2012 Venus transit |
Recently, humanity was treated to a rare event in the heavens; from our vantage point on Earth we were able to see the transit of the planet, Venus, across the visible disk of the Sun. A planetary transit is analogous to an eclipse, because it involves one object passing through the line of sight between two other objects. Similar to a solar eclipse, especially a partial solar eclipse, where the Moon passes between Earth and the Sun and blocks a portion of the Sun’s light, a transit of Venus occurs when Venus passes between Earth and the Sun blocking our view of a region of the Sun’s disk. Since this type of event requires a very precise alignment of the Sun, Venus, and Earth, it is quite rare. Although the previous alignment occurred only 8 years ago, in 2004, you have to look back historically to 1882 to find the next previous alignment, and looking to the future it will not be until the year 2117 before the alignment happens again (Espenak, 2012). Thus, in all likelihood, being 105 years in the future, there will be no one alive in 2117 who saw or was old enough to remember this year’s transit of Venus. (For those who may have missed seeing any of the event or press coverage, see the links at the end of the article for more images and videos.) At this point, let’s pause and contemplate some unique considerations this recent transit event offers.
Astronomically, the Sun and Venus are the brightest and third brightest celestial objects in Earth’s skies (the Moon being second), and historically are two of the most studied celestial objects. Ancient records dating back to the Babylonian civilization around 3000 B.C., reference this bright celestial object, and other civilizations such as the Chinese, Egyptian, and Greek civilizations include observations and cultural lore about Venus. Interestingly, historical references sometimes called Venus the “morning star” or “evening star,” and specifically the ancient Greeks called Venus by two names (Phosphorus and Hesperus) supposing it to be two different objects (Squyres, 2012). The two-object idea isn’t completely unreasonable, since for a portion of our year Venus precedes the Sun in the sky and for the other portion of the year it seems to follow the Sun across the sky. In fact, Venus is never more than about 48 degrees from the Sun in the sky (termed its greatest elongation, and is due to its orbit being inside Earth’s orbit). In fact, 2 Peter 1:19 makes reference to the “day star,” which is translated from the Greek word for phosphorus.
Commonly called “Earth’s Twin” or our “Sister Planet,” Venus is not only the planet that travels in its orbit closest to Earth’s orbit, but has such nicknames because it is nearly identical in size and mass. (Actually, the time of the transit of Venus represents the period of time for closest approach to Earth). When we consider this comparison it brings to mind the question, “What would an Earth transit event look like?” If we were to step outside of our own orbit and align ourselves looking back toward Earth, similar to the alignment we have seen with Venus and the Sun, then based on the similarity between Earth and Venus we actually have our answer. An Earth transit would basically provide the same stunning sight—a single distinguished planet, a fraction the size of the Sun, slowly crossing the wide, intensely bright solar landscape. Earth, too, is more than 100 times smaller in diameter than the Sun and approximately one million times smaller by volume. Therefore, this rare event of Venus’ transit affords us an interesting self-reflection to consider our own planet’s size, scale, design, and place in the Solar System.
Consider: as we watched Venus traverse the Sun’s disk, we were watching Earth’s closest planetary neighbor pass in front of Earth’s nearest stellar companion. Likely the most obvious observation from this event was the size comparison. Venus’s dark silhouette against the Sun’s surface portrayed such a small planet, but the truth is that the actual physical size comparison is even more extreme than what was observed. At the time of the 2012 transit, Venus’s angular diameter was approximately 58 arcseconds while the Sun’s was approximately 1,890 arcseconds, a factor of 32.6 times greater (Odenwald, 2012). However, since Venus was much closer to Earth than the Sun it appeared larger than if it had been at equal distance. This fact means the size of the Sun versus Venus is even more dramatic than the transit view appeared. In actuality the Sun is greater than 100 times the diameter of Venus and greater than one million times the volume, providing a perspective for the true scale of our Solar System. Sometimes the statement is made, “The Universe just has too much wasted space to be the result of an intelligent creator” (see Miller, 2003 for an article addressing that subject). However, this incredible scale of size and distance within our Solar System illustrates (1) the infinite nature of the Creator, and (2) an important aspect to God’s design for our life-sustaining planet. The following considerations should help illuminate some of the usefulness and purpose for the scales we see.
How does Earth compare to our nearest planetary companion? Although Venus and Earth are approximately equal in size and mass, Venus is an interesting case study in planetary characteristics, since in actuality, it is extremely different from Earth in most ways. From a distance we first notice that Venus is enshrouded in a thick atmosphere of clouds. This atmosphere is far thicker than Earth’s, mostly composed of carbon dioxide (CO2), and has an atmospheric surface pressure 90 times greater. To experience an equal amount of pressure on Earth you would have to travel nearly one kilometer below the surface of the ocean (“Venus,” 2012). Venus’s carbon dioxide dominated atmosphere, along with solar irradiance being double that of Earth’s (caused by its closer proximity to the Sun), results in Venus having the hottest average surface temperature in the entire solar system, over 860 degrees Fahrenheit (464 degrees Celsius). Such an incredible temperature means liquid water is not present on its surface, compared to more than 70% coverage on Earth’s surface, and incredibly, even metals such as lead and zinc would melt on its surface (Bentor, 2010). Another major contrast between the two planets is the presence of a strong magnetic field. Earth’s rather fast rotation is thought to drive a dynamo effect that maintains a steady and sufficiently strong field to provide a finely tuned cocoon of protection from the dangerous streams of charged particles flowing from the Sun through the inner Solar System. By contrast, Venus has an extremely slow rotation, which causes its day to be longer than its year, and lacks any magnetic field and associated protection from the solar wind. When we consider our “Sister Planet,” we find that it is not a “Twin” where we would want to or could live. These observations lead to the simple acknowledgement that Earth’s position in the Solar System is well-tuned and finely designed for life to thrive. The Earth shows itself to differ from all other planets in that it possesses all the necessary constituent elements to make it suitable for human life.
Observations of Venus have been linked to prominent times in history and have served to mark events and history, as many major celestial observations and events have. Examples of such help to illustrate just how important the view of our Universe is, and how the created purpose specified in Genesis has been demonstrated: “Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons, and for days and years” (1:14). The consistent, unwavering behavior of the motion of the planets—behavior which allows scientists to predict precisely when Venus will transit in this way again decades in the future—is not a characteristic that would result from randomness, mindlessness, and accidental processes as evolutionary theories suppose. Rather, such behavior points to the existence of laws governing the Universe and its planets—laws which could not have written themselves, but rather, were written by the Great Lawmaker of the Universe (Job 38:33).
Venus Multimedia:
1) NASA video:
2) National Geographic Images: http://news.nationalgeographic.com/news/2012/06/pictures/120606-venus-transit-2012-pictures-sun-planet-nasa-space-science/#/venus-transit-pictures-2012-sdo-yellow_54600_600x450.jpg
3) NASA Image of the Day Gallery: http://www.nasa.gov/multimedia/imagegallery/image_feature_2271.html
4) Sky and Telescope viewing from around the globe: http://www.skyandtelescope.com/observing/home/2012-Venus-Transit-ST-Reports-157500315.html
REFERENCES
Bentor, Yinon (2010), “Periodic Table: Melting Point,” Chemical Elements, http://www.chemicalelements.com/show/meltingpoint.html.
Espenak, Fred (2012), “Six Millennium Catalog of Venus Transits: 2000 BCE to 4000 CE,” NASA Eclipse Web Site, http://eclipse.gsfc.nasa.gov/transit/catalog/VenusCatalog.html.
Miller, Dave (2003), “The Universe—A ‘Waste of Space’?” Apologetics Press, http://www.apologeticspress.org/APContent.aspx?category=12&article=1207.
Odenwald, Sten (2012), “The Cultural Impact of the Transit of Venus,” 2012 Transit of Venus—Sun-Earth Day: Shadows of the Sun, http://venustransit.nasa.gov/2012/articles/ttt_76.php.
Squyres, Steven W. (2012), “Venus,” History.com, http://www.history.com/topics/planet-venus.
“Venus” (2012), Nine Planets, http://nineplanets.org/venus.html.
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