Wednesday, January 30, 2008

Surprises from Mercury

Earlier today, NASA had a press conference discussing the MESSENGER spacecraft's flyby of Mercury. It hasn't been very long since the data were acquired, and the excitement of the scientists on the panel was tangible. The results are still being interpreted, and some of them are very puzzling.

The most exciting result (in my opinion) was this image:

Nicknamed "The Spider", this crater is about 40 km in diameter and is surrounded by a bunch of radiating troughs. It also happens to be right smack in the middle of the huge 1500 km-in-diameter Caloris basin (which, by the way, is even bigger than scientists previously thought). The mysterious troughs are almost certainly tectonic features related to the ground in the center of the basin bulging and cracking, probably due to the intrusion of molten rock underground.

Everywhere else (that we know of) on Mercury, all we see is compressional tectonics, so this "spider" is really unusual. What caused all the bulging that formed the spider? Nobody know, but I'd bet money that it's related to the Caloris impact.

The recent flyby collected more than 1200 images, plus spectra, and topography data, and this is only the tip of the iceberg. There are two more flybys planned, and then the spacecraft will be in orbit around Mercury, possibly for years. Who knows what other surprises are in store?

Thursday, January 17, 2008

E.T. Phone ... Us?

There has been some news lately about a signal detected at Arecibo that was reported to be potentially from extraterrestrial intelligence. Unfortunately, it appears that E.T. is not calling us, it was just that the reporter who wrote the story was lacking in any form of intelligence, terrestrial or otherwise.

Phil Plait at Bad Astronomy has the details.

Wednesday, January 16, 2008

MESSENGER's new views of Mercury!

The Messenger spacecraft just did a flyby of Mercury and has returned the first of what are sure to be many spectacular images.

In the upper right hand side of the planet, there is a large, roughly circular, lighter toned area. This is the Caloris basin, so named because it is the point on Mercury that faces the sun when the planet is at perihelion. Before this image, the best pictures of Mercury's surface were those taken in 1974 by Mariner 10. The Caloris basin was right on the terminator (the transition between day and night) at that time, so everything to the west of the basin in this new image has never been seen before. Ever. By anyone.

Over the next few days, we should be seeing some more new images as they are sent back to Earth. Messenger will fly by Mercury again on October 6, 2008 and September 29, 2009 before finally settling into orbit around the planet in March of 2011. Once in orbit we will really begin in earnest to learn about this neglected planet.

For more detailed information, check out the Planetary Society Blog and Bad Astronomy.

Monday, January 14, 2008

Asteroids Miss Mars and Earth

Well, it looks like Mars is not going to be hit by the asteroid that was causing a buzz a few weeks ago. Here's a cool animation showing the decreasing uncertainty in the asteroid's path as more data was gathered.

In other news, on January 13, a 27 meter asteroid passed by earth at about the distance of the moon. Check it Out.