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Mars makes its closest approach in 15 years this summer: How to see it

The Hubble Space Telescope captured this view of Mars on May 12, 2016, a few days before the sun and Mars were on exact opposite sides of the Earth.

(J. Bell (ASU)/M. Wolff (Space Science Institute)/NASA/ESA/Hubble Heritage Team (STScI/AURA))

From the beginning of June and then in July and August, who gaze skyward toward the east-southeast during the evening hours will almost certainly will be a brilliant orange-red “star” shining with a steady light. Many will undoubtedly wonder what the object is. “Sure,” many will think, “nothing is so bright and colorful was clearly here for. Where did it come from?”

In fact, this is not a star but a planet: Mars. This year, until now, the Red Planet is visible only for the early birds, and while it was light, it was not exceptionally so. But with the passing of the night, Mars has risen in a little earlier and getting a little closer to the Earth.

And this summer will be a favorable opportunity to see the famous Red Planet. At the end of July, Mars will come closer to the Earth than it has since 2003. The planet in opposition with the sun on the 27th of July, which means that it will be opposite the sun in the Earth from the sky, only 51 days before the passing of the perihelion — its closest point relative to the sun in its orbit. As a result, the minimum distance of Mars to the Earth will shrink to approximately 35.78 million km (57.58 million kilometers) on 30 July, when the planet is clearly disk diameter will be as large as 24.3 arc seconds — just shy of the largest it can ever get, 25.1 arc seconds. [Mars in Opposition Of 2018: How to See It, and What to Expect]

On that day, on the Red Planet will blaze at magnitude -2.8 — twice as bright than Jupiter, but less sharp than Venus. (Lower magnitudes are brighter.) If you look through a telescope with an eyepiece with magnifying glass 75 power, Mars’ disk will appear as large as the disk of the moon with the naked eye.

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Atmospheric instability will pose a problem

However, Mars in the far south when it is at its best; and it will be in the zodiac constellation of Capricornus, the sea goat, with a declination of -25.8 degrees. As such, observers in the northern latitudes will never see the planet very high in the sky, so atmospheric turbulence will impair the view more than normal.

In fact, for the observers in most of the United States, Mars will be so low in the sky to interfere with telescopic work. When the planet passes the meridian and reaches its highest point in the sky around 1 a.m. local daylight time, Mars altitude above the southern horizon will be only 23 degrees, as viewed from Chicago and 30 degrees from Los Angeles.

Remember that your clenched fist held at arm’s length measures roughly 10 degrees in width. So, for skywatchers in most of the United States, Mars will appear no more than two or three “fists” above the horizon.

Conversely, observers in South America, South Africa and Australia will be presented with an exceptional viewing opportunity, the planet will pass almost right above your head. [Preview 2018 Year of Spectacular Mars with the Help of Mobile Apps]

South pole will appear to shrink

The Martian telescopic drive will appear at least 14 arc seconds in diameter almost five months, from May 24 to Oct. 13 — is greater than it has been for this extended interval for more than a decade.

On Mars, this period corresponds with the arrival of autumn (22 May) and in winter (Oct. 16) on the planet’s northern hemisphere, and on to the spring and summer in the southern hemisphere. Mars has seasons like that of Earth, but they are on average almost twice as long. Because the Martian south pole is tilted in the direction of the Earth from now through the rest of 2018, the southern polar cap will be perfectly presented to us. In June, the typical winter cloak of clouds over the arctic region should disappear, while the south cap seems brilliant and undergo dramatic changes during the rapid spring thaw.

So, as winds down, the cap will be near its maximum extent and subsequent seasonal shrinkage the most compelling to follow. Many interesting, and sometimes surprising, seasonal changes happen on Mars during this period.

Exploring and recording the Martian landscape

Around the time that Mars is closest, even a 3-inch (8 cm) telescope can show dusky markings on her small, red disk, as well as the bright white of the polar cap. However, a telescope with an aperture of at least 6 inches is usually recommended for visual observations of this planet; magnifications of 150 to 200 power need to offer the best views. If you have a 10 – to 12-inch (25 to 30 cm) telescope, 250 to 300 power is recommended. You can then follow the planet’s dark markings, the south-polar cap, clouds and mists.

Some astronomers used to think that the Red Planet’s dark surface markings were vegetation, but space probes in the 1960’s and ’70’s revealed the markings to be vast expanses of rock and dust. The storm sometimes move the dust, resulting in both seasonal and long-term changes.

Those who carry out systematic observations can contribute some useful knowledge about Mars weather and road conditions. If you are interested, you can contact ALPO — Association of Lunar and Planetary Observers — that is an observation-section that is specially dedicated to Mars.

If you are a beginner, even with a large telescope will show little when you your first look at Mars. But if you inspect the planet night after night, your eye will gradually become accustomed to the low contrast and soft boundaries of the spots on the disk. You will quickly grow familiar with the Martian rotation, allowing markers to move across the disk from right to left as seen in an astronomical telescope with an inverted field by an observer on the south. As a result, a certain function, go to the center of Mars’ disk around 40 minutes later than the night before.

Regardless of how you plan to look at Mars in the coming weeks — either with a telescope or with just your eyes — it will prove to be a striking object, attracting the attention of even the most casual of skywatchers.

Really, this is the summer of Mars!

Original article on Space.com.

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