Mars will be the closest to earth it's been in 15 years tonight

If you missed the glorious display from a blood red moon and radiant Mars during the weekend's early morning eclipse, there's another opportunity to get a good glimpse of the red planet tonight – Mars will be the closest to Earth it's been in the last 15 years.

Unlike the eclipse, (which was more lengthy than usual but still a tough one to catch if you're usually in bed at 5.30am on a Saturday), this planetary performance can be enjoyed over the course of several hours tonight – and in the next few nights too.

The red planet is closer than usual.

Photo: NASA

"Mars is at its closest to earth in 15 years [tonight], but tomorrow and the next day and the next day it will be pretty good as well," says University of Sydney astronomer Tim Bedding.

Viewing it is easy, he adds. "Mars will be rising as the sun sets, and rising higher and higher in the eastern sky during the evening. Later in the evening it will be more prominent, passing overhead at midnight.

"You can’t miss it, it’s the bright reddish-orange thing in the sky."

The red planet will be a mere 57.6 million kilometres away from Earth, which is the closest it's been since 2003 – the last time Earth overlapped its orbit of the Sun.

That overlapping is called the Opposition – and it happens every 2.1 years. But as Professor Bedding explains, because the orbit is elliptical, every seven laps (or approximately 15 years) the Earth overlaps it at a closer point.

But it's not just Mars putting on a show at the moment. Venus and Jupiter are also visible and bright.

"It's a good chance for people to go out and enjoy the sky, especially those of us who often don't do that, especially if you live in the city where the light pollution stops you seeing very much," Professor Bedding says.

"This is not an event you have to rush for. It's not like an eclipse, where if you miss it it's over. You can go back any night for the next few weeks and Mars will still be beautiful. Jupiter will still be beautiful overhead, Venus will still be beautiful in the west."

There's something about Mars
The discovery of a 20-kilometre-wide lake under the southern ice cap on Mars by the European Space Agency's Mars Express orbiter this week has renewed the question not just of whether there's life on Mars, but what that life might be like.

So here are a few hard facts. Mars is about half the size of Earth, so gravity is weaker there — only a third what is on Earth and so you could jump higher, that is, if you could take a breath.

The Martian atmosphere is mostly carbon dioxide, and there is very little of it anyway, the pressure is less than 1 per cent of air pressure here. Temperatures on the ground range from 30 degrees celsius to -123 below. A day there is 24 hours, 39 minutes and 35 seconds long and a year is 687 Earth days.

It is, as a travel brochure would say, a land of dramatic contrasts, with the solar system's biggest volcano, Olympus Mons, 24 kilometres high, and the longest canyon, Valles Marineris, 4023 kilometres long and 6 kilometres deep.

As far as we know, it is inhabited mostly by our own robots, like the rovers and the Vikings we have sent there, and the wreckage of lost landers.

Some 45 space missions — not all of which made it — have been launched toward Mars by humans. There are five on the docket, including efforts by China and the United Arab Emirates, planned for the summer of 2020.

If anybody else has been interested, if there is anything like an alien iPhone or one of those monoliths from 2001: A Space Odyssey, sitting on a rock somewhere, we wouldn't necessarily have found it yet.

Out of all this exploration a new story has emerged, equally haunting. It is of a planet once splashed by oceans and carved by swiftly flowing rivers, a world warmed long ago by an atmosphere.

But something happened, and Mars lost its sparkling waters and its air.

Now there are only the naked shorelines, empty filaments of tributaries, silent rocks and occasional wet spots on cliff sides. If there was ever life here, the story goes, it died or went underground.

with New York Times

source: https://www.theage.com.au/national/mars-will-be-the-closest-to-earth-it-s-been-in-15-years-tonight-20180731-p4zuoc.html