Part 2. Recent and historical images of Mars
Historical Image of Mars.
Website reference: http://www.fourthplanet.space/tag/christiaan-huygens/
Image info: Christiaan Huygens’ observational drawing of Mars shows a triangular feature which known today as Syrtis Major.
Telescope used: Huygens used a telescope created by himself (1655). It was a good 2-inch (5.1-cm) telescope of 10.5-foot (3.2-m) focal length and 50x magnification. (Sheehan)
Observer: Christiaan Huygens
Exposure time: Observations were taken over a number of weeks.
Other relevant details: Huygens used results of his observations of Mars to measure Mars’ rotational period. He measured it as 24 hours (only one hour away from the rotational period of the planet recognized today). It should be noted that the most prominent and largest crater of the Mars was named after Huygens (14.0°S, 304.4°W; 467 km).
Any historical comments about the object by the observer: Based on his observations, researcher also made a sketch of planet’s south polar ice cap.
Picture 1 Huygens observational drawing of Mars (Grego ix)
Additional image of Mars
Website reference: http://hubblesite.org/image/3733/news_release/2016-15
Additional information: http://heritage.stsci.edu/2016/15/fast_facts.html
Image info: On May 12, 2016, Mars was 0.53 astronomical unit (50 million miles or 80 million kilometers) away from Earth. Image allows to see relatively small details of the planet (20-30 miles across).
Observers: The Hubble Heritage Team: Z. Levay (PI), M. Mutchler, J. Mack, R. Avila, C. Christian, L. Frattare, J. Green, C. Martlin, S. Meyett, and S. Porter (STScI/AURA), K. Noll (NASA/GSFC), J. Bell (ASU), and M. Wolff (Space Science Institute)
Exposure time: 24 exposures were taken on May 12, 2016
Telescope used: NASA Hubble Space Telescope
Filters used: This image is a composite of separate exposures acquired by the WFC3/UVIS instrument. Several filters were used to sample various wavelengths. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. Filters used: [S II] 6717/6731 filter F673N (red), [O III] 5007 filter F502N (red), Strömgren v filter F410M (green), UV filter F275W (purple)
Other relevant details: This image was taken on May 22, eight days before Mars was on its closest distance to Earth in eleven years – 47.4 million miles. On May 30 Mars and the Sun were directly on opposite sides of our planet.
Picture 2 Image STSci-PRC16-15a (Hubblesite)
Part 3. Short essay about Mars
Mars is the fourth terrestrial planet. The planet’s orbit lies between the orbits of Jupiter and the Earth. Mars moves along its orbit with average speed of 24 km/s at distance (average) of 227.9 million kilometers from the Sun. One Martian year lasts 1.88 Earth year or 687 days. Its synodic period is 780 Earth days. Four terrestrial planets are depictured on Picture 3 below in scale.
Picture 3 Terrestrial planets of the Solar System: Mercury, Venus, Earth, Mars (ESA)
Planet’s orbit is inclined by 1.9° to the plane of the ecliptic, has an eccentricity of 0.09. The minimum distance from Earth to Mars is 55.7 106 km, the maximum distance is 401.3 106 km. (Grego 5) Various parameters of this celestial body in comparison to parameters of Earth are given in Table 1 below.
Mars was one of six planets known to ancient astronomers. The Egyptian priests called it Har Décher that means the “Red One”. In Babylon it had a name of Nirgal that can be translate as the “Star of Death”. Astronomers from ancient China observed the Red Planet even before the Zhou Dynasty ruled the China (since 11 century B.C.). Romans gave the name Mars in honor their god of war. (Murray and Barnard 6)
The emergence of telescopes in the beginning of the 17 century marked the new age of observations of celestial bodies. Johannes Kepler was first to calculate the shape of the planet’s orbit. He also discovered that orbits of all planets have the shape of an ellipse and not of a circle. In 1610, Galileo Galilei was the first to observe Mars using telescope. However, his instrument had not enough magnification power to see any tiny details on the surface of the planet. (Hotakainen 20) Dutch astronomer Christiaan Huygens created an improved telescope and managed to do first observations of Mars’ surface in 1659. He is credited for discovering the planet’s polar caps and estimated duration of Mars day. The idea of possible life on Mars was born in late 18 century influenced by William Herschel’s comparisons of various parameters of Earth and Mars. In mid-late 19 century first color maps of the planet were drawn by Italian scientists Angelo Secchi and Giovanni Schiaparelli.
Colossal step forward in space research happened in mid 1960s when first spacecrafts were created. In 1965 NASA’s Mariner 4 made first surface photos of Mars during its flyby of planet at distance 9,846 kilometers of the surface. In 1971 Mariner 9 was the first spacecraft that successfully finished orbital flight around the Red Planet. First landers that actually reached Mars’ surface were two NASA’s Viking crafts launched in 1975. Four Mars rovers were launched by NASA since 1996: Sojourner, Spirit, Opportunity and Curiosity. The latest and largest of them is Curiosity that arrived in Gale Crater on August 2012. (Aderin-Pocock 112-34) The U.S. space agency’s Mars Exploration Program has four key science goals: to determine whether life ever arose on the Red Planet, to characterize the planet’s climate, to characterize its geology and to prepare for future human exploration. (NASA "Nasa's Mars Exploration Program's Science Theme")
Astronomers think that the Red Planet has had three major time periods: the Noachian Age, Hesperian Age and Amazonian Age. All three ages were named after notable geographic areas of the planet. The Noachian era began somewhere around 4.5 billion years ago and lasted till 3.5 billion years ago. It is possible that this time period had warmer climate that allowed for surface lakes, rivers and even oceans to exist. During the Hesperian Age, volcanic activity has substantially slowed down and the climate became colder. It ended roughly 2.5 billion years ago. Torrential flash floods cut wide channels on the surface. Later water retreated underground and transformed into ice. The Amazonian Age extends to the present. Today the planet is dusty and dry and has very thin atmosphere. Because of very low atmospheric pressure, any water that reaches surface instantly either boils away or freezes. (Murray and Barnard 22-23)
Mars does not have enough gravity to keep a dense atmosphere. 95.3 % of the planet’s atmosphere consists of CO2, the rest is N2, Ar and H2O vapor. There is almost no oxygen in its tenuous air. In upper layers of atmosphere, CO2 and H2O freeze and high clouds are formed. During springs, great storms occur that color the sky a reddish. This happens because of red dust puffed into the air by winds. In the polar areas, dust combines with icy vapors resulting in snow. (Murray and Barnard 24)
It is impossible for liquid water to exist on the surface of Mars in present conditions. However, many factors point that once the planet was full of liquid water, which volume was possible equal of even higher than on Earth. Among these factors are: various minerals formed by standing water, sedimentary rocks and specific landscape elements that may be found on the surface of the Red Planet. One of the most interesting example of such feature of the landscape is sites of two former giant waterfalls located at Kasei Valles. Their height is eight times more than height of Niagara Falls. (Aderin-Pocock 116) Another notable elements of Mars’ landscape are channels, or calani as they were initially named by Schiaparelli. (Hotakainen 111) For more than century there were a lot of disputes among astronomers about nature of these structures. However, images received from Mariner-9 proved that most of canals are just optical illusions.
The surface of the Red Planet is dominated by volcanoes and lava plains. Mars has largest volcanoes in the Solar System. According to scientists, the most recent eruption of the planet’s volcano happened about 2 million years ago. However, many of them believe than major volcanic events may occur in the future. Tharsis is the largest volcanic region of Mars. There are two main types of Martian volcanos: mons (or shield) type and tholus (or dome) type. (Murray and Barnard 42) Olympus is the largest volcano in the whole Solar System and it rises 22 kilometers above the planet’s surface. The width of Olympus is almost 610 kilometers.
Deimos and Phobos are two moons of Mars. These celestial bodies have irregular shape and heavy cratered surfaces. Moons are so tiny that some scientists believe that they are just the asteroids captured by the planet’s gravity. Phobos and Deimos were discovered in 1877 by Asaph Hall.
Works Cited:
Aderin-Pocock, Maggie. The Planets: The Definitive Visual Guide to Our Solar System (Definitive Visual Guides). DK Publishing, 2014. Print.
ESA. "A Comparison of Terrestrial Planets." European Space Agency 2005. Web. 01.31.2017.
Grego, Peter. "Mars and How to Observe It." Mars and How to Observe It. Springer, 2012. 127-33. Print.
Hotakainen, Markus. Mars: From Myth and Mystery to Recent Discoveries. Springer Science & Business Media, 2010. Print.
Hubblesite. "Mars near 2016 Opposition." HubbleSite 2016. Web. 01.31.2017.
Murray, Stuart, and Edward S. Barnard. Mars. DK Publishing, 2004. Print.
NASA. "Mars Fact Sheet." NASA 2016. Web. 01.31.2017.
---. "Nasa's Mars Exploration Program's Science Theme." NASA 2016. Web. 01.31.2017.
Sheehan, William. The Planet Mars: A History of Observation and Discovery. Tucson: The University of Arizona Press, 1996. Print.
