Sky's Up July - September 2018 | Page 18

Mars

This mosaic of Mars ’ Valles Marineris hemisphere is composed of

102 Viking Orbiter images . attacks !

10

Get your telescopes ready for a big show

By DR . MIKE REYNOLDS
Guest Contributor
This summer we are in for an astronomical treat : the red planet Mars will be fairly close to Earth . This is called an opposition , which in this case Mars is on one side of Earth and the Sun on the other ; opposite of each other . Oppositions of Mars
Sometimes the
Earth-Mars distance is such that Mars is not very impressive in small telescopes . But when oppositions of Mars are close , the Red Planet can be quite spectacular . And this Mars opposition is a
REALLY good one ! Mars will be about 35,785,537 miles from Earth . occur about every 26 months . Mars is a favorite of many amateur and professional astronomers . Because of its proximity to the Sun , surface features , clouds which occasionally are seen to form and polar caps , a number of 19th and 20th century astronomers thought Mars harbored life — perhaps even intelligent beings . Some observed what they thought were Martian-built canals and oases . Astronomers realized that the planet was barren with the Mariner 4 spacecraft fly-by of Mars in July 1965 . Yet Mars seems to be a good place for at least microbial life , and there are some hints found by Martian landers , rovers and orbiters that Mars had flowing water on its surface at one time and might still have some sort of underground water . The orbits of Earth and Mars are not perfect circles . Add to that these orbits do not stay the same distance apart . So some Martian oppositions
COURTESY OF NASA are better than others . Sometimes the Earth-Mars distance is such that Mars is not very impressive in small telescopes . But when oppositions of Mars are close , the Red Planet can be quite spectacular . And this Mars opposition is a REALLY good one ! Mars will be about 35,785,537 miles from Earth . This close approach also means that the Red Planet will be very bright . Mars sports two diminutive moons : Phobos and Deimos . Both were discovered by American Astronomer Asaph Hall at the United State Naval Observatory in 1877 . Phobos means fear or panic and Deimos terror or dread . Both moons are not even close to being spheres in shape . Phobos at its largest is about 13.8 miles in diameter , and Deimos is about 7.8 miles in diameter . The best opposition of Mars in the last 60,000 years ( yes , you read that right !) occurred in 2003 . We were only 34,646,418 miles away from Mars . That very close opposition will not be repeated until 2287 . You might see some text messages , Facebook posts , emails or other social media which state Mars will be so close to Earth this summer that it will look as large as the moon ! Don ’ t believe it . This same message circulated during the 2003 Mars opposition , and a number of people believed the story . Think about what it would mean for Mars
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