AMARSZING!

by William J. Bechaver

Alas, our chance to view amazing Mars close up is here!

This week, on Thursday 26 July, Mars will be at opposition, the position in the sky when the red planet is directly opposite from the Sun!

So, right when the Sun is setting in the west, Mars will be rising in the east. The event actually occurs shortly after midnight that night, in the early morning hours of Friday.

The orbits of Earth and Mars around the Sun are elliptical, meaning that sometimes the orbits of the two planets come closer to each other than at other passes. This year’s opposition causes the Earth to come closer to Mars than during previous passes. So the time to view Mars at its closest is now.

However, due to that ellipticity of their orbits, even though at opposition on Friday, the day when the two should be closest together, that event doesn’t occur until a few days later. Even though we are past Mars on Friday, the orbit of Mars will cause the planet to come a little closer to Earth a few days later, on the night of Monday 30 July. On that night, Mars will be only about a hundred thousand miles closer to Earth, a distance that is certainly not observable from here.

However, when we started watching Mars a couple of months ago, it was an impressive 72 million miles distant. Now in the short span of about nine weeks, we have closed the gap, and will be less than half the distance, being only 35.7 million miles away!

The viewing opportunities for Mars will actually improve during the next couple of weeks, as we pass it, and it begins to rise earlier every night, bringing it high into the sky during the early evening hours for prime viewing.

This is a wonderful opportunity to view Mars at its closest. After this weekend, the race is won, and Earth will pass Mars. We won’t catch up to it again until mid October in the year 2020! And then, our orbits being situated as they are, we will be a full 3 million miles more distant from the red planet on our next closest approach, so this is our chance to view Mars at its closest.

The other big event of July 27 will be the total lunar eclipse. An eclipse of the Moon occurs when the Earth passes between the Sun and casts it’s shadow on the surface of our satellite.

This year’s event has been touted at the longest for the duration of totality this century! But, even so, we can not view even a moment of it from mainland America. The entire event will occur when it is night and the Moon is high in the sky on the other side of the planet, during our daylight hours.

But this does afford us another viewing opportunity, even though we will completely miss out on the total lunar eclipse. Mars and the Moon both being essentially at opposition on the same night, the full Moon will join brilliant Mars in the sky on Thursday night, coming closest to the red jewel in the sky just before dawn on Friday morning. So, anytime during the night, go out and look for Mars riding with the full Moon across the sky!

And, for a total lunar eclipse, we in the Americas will only have to wait until January, when the next total lunar eclipse will occur.

Thanks for your continued interest in our astronomy columns. If you have any questions or article requests, contact us at spacescape@rocketmail.com, or follow us on Twitter @ColoSpacEScapE for updates and additional viewing opportunities, and upcoming Mars viewing dates!

• · William J. Bechaver is the director of SPACE • Spanish Peaks Amateur Cosmos Enthusiasts, the premier Astronomical Society for Southern Colorado and Northern New Mexico.

OUR “CLOSE” ENCOUNTER WITH PLUTO

by William J. Bechaver

Well, recently we’ve been focusing on our upcoming close encounter with Mars, and we’ve looked at several of the other planets when they were at opposition. But in all the tumult, we’ve almost overlooked Pluto.

Opposition occurs when one of the outer planets is opposite the Sun in our night sky. When opposite the Sun in the sky, we are on the same side in our orbits, and therefore, closest to them. Earlier this year, it happened with Jupiter, then with Saturn, and later this month, it will happen with the closest planet, Mars.

These encounters, easily observable, have made the headlines. But this week, there will be a “close” encounter of which you may not be aware.

On the night of Thursday 12 July, Pluto will be at opposition, and so we will be closer to it than any other time this year!

Just how close will we be to distant, tiny Pluto? On the night of our closest encounter, and the best night to observe the planetoid, we will approach to just within a little over three billion miles away!

That’s right, at the closest, it still takes a message, traveling at the speed of light, over four and a half hours to reach tiny Pluto, and that’s the closest we’ll ever be.

You can’t see Pluto except through very fine telescopes, so seeing it that night, even though it is closest, and at its best viewing from Earth, will be next to impossible. So that’s the closest encounter I’ve ever mentioned, that you can’t see. But, there will be a few others in the future.

Amazingly, on that same night, Mercury, the closest planet to the Sun, will be at greatest elongation, or highest in the west that it is going to climb. This is our best opportunity to view it, as well, when it’s furthest from the glare of the Sun.

However, it too is so tiny, finding it on that night will be difficult. But two nights later, on Saturday the fourteenth, the Moon will pull up right along side, lying just two degrees to the north of Mercury. So, go out just after sunset on Saturday, and try to spot tiny, faint Mercury to the left of the splinter crescent Moon.

The next evening, Sunday, go out at about the same time, and see a beautiful pairing of the crescent Moon with brilliant Venus, higher in the sky, and unmistakable, as Venus is currently the brightest thing in the night sky, not counting the Moon, of course. They will continue to get slightly closer together as they both sink to the western horizon, and set together just after ten thirty.

Through it all, the close encounters and amazing pairings, the planet to watch this month remains to be Mars. We will be closest to it in a few short weeks!

And as it blazes red in the early morning sky, it grows closer every night, as we close on it in our orbit.

When we began to take note in May, we were 72 million miles from the red planet. Now, a mere two months later, we have closed the gap considerably, and are currently only just over 38 million miles away! That’s less than half the distance from the Sun! And nearing half as far as when we first began!

So there’s plenty of observing to do if we can get out on a couple evenings this week, and spot the planets, both great and small, near and distant.

Thanks for your continued interest in our astronomy columns. If you have any questions or article requests, contact us at spacescape@rocketmail.com, or follow us on Twitter @ColoSpacEScapE for updates and additional viewing opportunities.

• · William J. Bechaver is the director of SPACE • Spanish Peaks Amateur Cosmos Enthusiasts, the premier Astronomical Society for Southern Colorado and Northern New Mexico.

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