Mars is Back! but playing hide and seek.

by John Hlynialuk

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Image above is a Hubble Space Telescope image and shows much more than you can see with a telescope.


Mars in 2018 -closest since record close approach of 2003

The close approach of Mars to Earth in 2003 is being repeated this year. The orbit of Mars is an ellipse and only every 15 to 17 years or so do the distances line up so that we get a better than average separation from the Red Planet . From 2018 onwards, oppositions of Mars gradually get farther and farther (until Sep 2035) so this year is the time to get out and pay some serious attention to the planet.

One or two viewing occasions are not going to do it, however. The planet is not as high in the sky as it has been at other oppositions so our atmosphere will play a significant role in your not seeing Mars at its best. You need to be persistent and get out often as you pursue Mars. You need a combination of dark, clear skies, good seeing and maximum altitude above the horizon to be rewarded with better than average views.

The map/diagram below from Sky&Telescope shows the main features of the planet. But there are other sources of detailed information as well.

Mars viewing guides can be found here:
SkyNews Mars Guide and here from Cosmic Pursuits: Cosmic Pursuits Mars Guide as well as here: Sky&Telescope Mars viewing There is also a Mars app that shows which face of Mars is visible at your observing time. Called Mars Profiler the link is here: S&T Mars Profiler

MARTIAN DUST STORM
On the down side a big dust storm started up in mid-May and continues to shroud the entire planet. Features of the surface have been pretty much obliterated and will remain so until the dust settles. Details of the storm’s development can be found here:
Martian Dust Storm and here: Dust Storm Update but a quick synopsis follows.

The storm started in the opposite (northern) hemisphere from where they normally occur and then expanded into southern regions so by June 19, the entire planet was shrouded. NASA’s Rover Opportunity which went into a hunkered-down mode has not been heard from since June 10.


Amateur observers have been chewing their nails waiting for a break in the storm but the only things noticeable are an overall fifth of a magnitude increase in brightness and a subtle change in the colour of the planet from its usual reddish-orange (or pink) to a pumpkin orange hue. Few telescopic observers have noticed even a polar cap glowing feebly through the haze.

Scott Guzewich, atmospheric scientist at NASA’s Goddard Space Flight Center, struck a note of optimism, writing in a July 5th blog that "the amount of dust over Gale Crater has been slowly declining over the last two weeks, and it’s possible the dust storm has reached its ‘peak”’. Once storms like this peak, it still takes several months for the atmosphere to clear to pre-storm transparency. This puts us into late August/September before things settle down. By that time, Mars will be well past its July 27 opposition. All is not lost however, since in late August, Mars crosses the meridian (its highest point above the southern horizon) around 11 pm and in late September that occurs around 9:30 pm. So if anything, Mars viewing will still be going on into the fall. The down side is that it shrinks from its 24 arc-second diameter on July 27 to 16 arc-seconds in late September.

The chart below shows Mars features as they will (eventually) be visible. Sky&Telescope has a great app called
Mars Profiler that will keep track of the visible face for you. Click on the link provided. And keep your fingers, toes etc, crossed for a quick clearing of the dust!



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