io9: messenger

Plan Your Space Vacation with the First Ever Map of Mercury

Lauren Davis — Thu, 17 Dec 2009 13:00:00 PST

If you're planning a trip to Mercury, you'll need the first map ever released of the solar system's innermost planet, a mosaic of photos from the Mercury missions.

The US Geological Survey's Astrogeology Science Center revealed the first map of Mercury this week at the American Geophysical Union meeting. The map is a composite of 917 images taken from various Mercury flybys. Photos from Messenger's flybys in January 2008, October 2008, and September 2009 account for 90.90 percent of the mosaic, with the rest provided by the Mariner 10 photos from the 1970s. The map is just shy of complete, covering about 97.72 percent of Mercury, but it's the closest thing we have to a complete map of Mercury.

[USGS Astrogeology via Wired]

Are Mercury's Days as a Planet Numbered?

Michael Reilly — Mon, 07 Jul 2008 09:48:59 PDT

Ever since the International Astronomical Union demoted Pluto to a dwarf planet (does it even deserve a capital "P"???) in 2006, astronomers around the world have been at odds to describe just what they mean when they say the word "planet." For the moment, the solar system is holding steady with eight of them, but late last week evidence returned from the Mercury MESSENGER mission showed that the smallest planet left is shrinking. One has to wonder: how long will it be before Mercury gets plutoed?

Mercury is about twice as big as pluto, but still is the smallest object called a "planet" orbiting the Sun. The question is: how much smaller will it get? It will never get anywhere near as small as the former ninth planet, but will the IAU see fit to demote it too as it continues shrinking? Only time will tell.

Meanwhile, Mercury's molten iron core continues to cool, shrinking the planet from the inside. Small particles of solid iron 'snow' rain down toward the ever-widening solid core. But even as the solid grows it's denser than the liquid and so takes up less space. This has been going on probably for billions of years and over time the shrinkage has caused Mercury's crust to buckle and fold up on itself, as seen here (that y-shaped fracture in the left side of the image is a huge fracture in the rock. The whole picture is about 200 kilometers wide):

(from NASA)

On the right hand side of the image, the craters with the soft-looking rims appear to be old impact basins that have been filled in with lava, indicating the Mercury once had some serious volcanoes exploding on its surface. Why did the volcanoes die off? Mercury cooled off. Just like on Mars and the Moon, Mercury was fiery when it first came into being, but lost its heat in the roughly 4.5 billion years since, silencing is volcanic activity. Earth is cooling in a similar way and in a few billion years it will get too cold for volcanoes too. When it does it will go quiet forever.

Source: Science, NASA, via LA Times

Mysterious "Spider Scar" on Mercury Revealed for the First Time

Annalee Newitz — Thu, 31 Jan 2008 07:00:38 PST

NASA's probe MESSENGER flew by Mercury a couple of weeks ago, and the photos have started pouring in. This is one of the most striking. Nicknamed "the spider," it's probably the result of a meteor impact with about fifty cracks radiating outward from it. Apparently, it's the only such structure in the solar system, making it officially cool.

[Special note to Moff and Blakeley: Just try making dick jokes about this picture! It can't be done!] Image courtesy of NASA/JHUAPL/CIW NASA Spots Mystery Spider Scar [Space.com]

First Ever Closeup Of Mercury

charliejane — Wed, 16 Jan 2008 14:30:23 PST

NASA's Messenger space probe finally sent back its first high-res images of Mercury's dark side, and they're surprisingly sparkling. Mercury's dark side is actually "illuminated obliquely" by the sun. Messenger is giving us our first real view of Mercury's Caloris basin, and may help to solve mysteries like why Mercury has a magnetic field when Venus and Mars don't, and what lurks in its shaded polar regions. Click through for the full image.

Make Your Own Mercury Porn

charliejane — Mon, 14 Jan 2008 14:30:23 PST

The Messenger Space Probe is flying past Mercury as you read this, taking pictures of the night side of the planet no human has yet seen. It'll be a while before we get images as cool as the 1997 NASA image on the left. But you can download realtime images from the probe's cameras, and combine them to make your own Mercury art right now. Click through for images and a tutorial.

NASA's Mercury Visualization Tool includes a slider bar. You can choose the time period of black-and-white images by the minute, the second and even the hundredth of a second. For each time period, there are images from the Wide-Angle Camera, the Narrow-Angle Camera and the sensor footprint. You can also choose a "phase" of the exploration, including WAC Approach Color Imaging or WAC Departure Mosaic.

Probably the best way to find the coolest Mercury images via this site is just to set a refresh rate of 1 second and then hit "play" on the slideshow. The site will jump forward in time a minute or so at a time. Just be prepared to hit "pause" when something good pops up. And then get ready to spend a few hours in Photoshop making your images sexier. Send us your best Mercury porn and maybe we can post a gallery. [Messenger Visualization Tool]