செவ்வாய்க் கிரகத்தை நாளை, நாளை மறுதினம் தெளிவாக காணமுடியும்

On July 30-31, 2018, Mars and Earth are closer than since their historically close approach in 2003. Mars was closer in 2003 than in some 60,000 years, and it’s now only slightly farther from Earth now than then. It’s some 35.78 million miles (57.59 million km) away at its closest on July 31 at 8 UTC. That time places Mars’ closest approach before sunrise on July 31 for North American time zones – and on July 30 at 10 p.m. Hawaiian Time.

This July 30-31, 2018 close encounter between the Earth and Mars is the closest until around the time of the Martian opposition on September 15, 2035.

Mars is closest in spite of the fact that Earth passed between Mars and the sun (the Martian opposition) on July 27. Read more about why below.

How about viewing Mars through a telescope now? Is it a good time? Is this a great time to look at Mars through a telescope? It should be because Mars is larger in our sky now, as illustrated below:

So put Mars viewing on your calendar for 2016. You won’t see Mars this size again until 2018, when Mars will put on an even better show. Illustration via nasa.tumblr.com.

Mars last came to opposition in 2016. It appeared smaller in our sky then, in comparison to 2018, as viewed through a telescope. Illustration via nasa.tumblr.com.

The telescopic view of Mars hasn’t been so great. Why not?

The answer is that planet-wide dust storms tend to spring up on the red planet around the time Mars is closest to the sun. Mars closest point to the sun happens on September 16, 2018. Dust storms on Mars began kicking up a few months ago, and the dust storms went global on Mars in early June.

That’s why most telescopic images of Mars we’ve seen this summer have looked like those below:

Jim Powell wrote: “Mars at 3 a.m. July 15, 2018. Only 12 days away from opposition, and it looks like those dust storms are starting to calm down a little bit. I’m seeing more detail today than I did 9 days ago when I last observed Mars.” Click here for updates on the Opportunity rover on Mars; it went silent in June due to Mars dust.

Rob Pettengill in Austin, Texas captured this image of Mars on July 23, 2018. He wrote: “Dusty Mars captured with a small telescope. Good seeing conditions in Austin gave me a chance to capture hints of surface detail and the south polar cap for the first time during this dust obscured opposition.”

Animation illustrating the effects of dust on our view of the Red Planet, via NASATumblr.

Why aren’t we closest to Mars on the day we pass between it and the sun? If both the Earth and Mars circled the sun in perfect circles, and on the same exact plane, the distance between Earth and Mars would always be least on the day of Mars’ opposition. But we don’t live in such a symmetrical universe. All planets have elliptical orbits and a perihelion (closest point) and aphelion (farthest point) from the sun.

Mars’ orbit around the sun takes 687 days in contrast to 365 days for Earth. It has a year nearly twice as long as ours. Earth’s closest point to the sun comes yearly, in January. Mars will be closest to the sun next on September 16.

At its opposition on July 27 – when Earth was directly between Mars and the sun – Mars was still drawing closer to the sun. And that is how its distance from us is smaller on July 31 than when Earth passed between the sun and Mars.

The time interval between a Mars’ opposition and its least distance from Earth can be as long as 8.5 days (1969), or as little as 10 minutes (2208 and 2232).

Generally speaking, Mars is brightest in 2018 from about July 7 to September 7. It is now shining more brilliantly than the planet Jupiter, and it’s not very often that Mars outshines the king planet!