Here's an experiment.  Prepare for 3 days of hiking.  Pack light-- sleeping bag, tarp, knife, matches.  Bring protein bars and rice for food.  And then pick up 3 gallons (11 liters) of water and start walking.  What's the heaviest part of your gear?  Of course it's the water.

If we're going to get anywhere in this solar system, we need to go where there is water.  Everything else can be dehydrated, miniaturized, made more portable.  You can even make oxygen from water, just by adding some electricity (such as from solar power).  But water-- which also makes up most of our body-- is the one item we so desperately need, but can't mimic.
Take a decently sized housecat. Let's say a cat that is well-fed and weights 7.5 kilograms. We can all comprehend such a mass. It's not too small, neither too big. A cat is something we can pick up and lift in earth's gravitational field.

A cascade of powers of six-and-a-half billion
New research says that sunspots provide an incomplete measure of changes in the sun's impact on Earth over the course of the 11-year solar cycle - good news for global warming proponents concerned that lower temperatures (and higher ones) may correspond to solar activity.

The study led by scientists at the National Center for Atmospheric Research (NCAR) and the University of Michigan found that Earth was bombarded last year with high levels of solar energy at a time when the sun was in an unusually quiet phase and sunspots had virtually disappeared.
I'm torn.  There's two ways I would make a new smash video game, "Astronomy Hero".

In the first, you are doing night observing runs, trying to accumulate enough light from each target while evading clouds.  Different targets appear at different times of night, and you have to balance whether to finish a given target (accumulate enough photons) or switch to something that just appeared in hopes that you can do better there.  Targets of different brightness or dimness require different 'stare' times that you're focusing on them, so you're constantly trying to maximize total on-target time while making sure the more valuable targets get done.
Stéphane Guisard, world-renowned astrophotographer and ESO engineer, has created a  340-million-pixel, 34 by 20-degree wide image from Paranal, the site of the Very Large Telescope, as it looks through an amateur telescope.

Guisard is head of the optical engineering team at Paranal.

To create this true-color mosaic of the Galactic Centre region, Guisard assembled about 1200 individual images, totalling more than 200 hours of exposure time, collected over 29 nights, during Guisard's free time, while working during the day at Paranal. 
In a little more than two weeks, NASA will have an expensive hunk of metal slam into the Moon... the resulting plume will be closely observed in hopes to learn more about the possibility of the existence of water ice (read more and learn about how you can participate). As the LCROSS vessel makes it way toward its impact site, NASA needs assistance with tracking due to its steep orbit; they only have brief and infrequent time frames to monitor the trajectory using their Deep Space Network of radio antennas.
"It looks, just looks fantastic," said Nicole Stott of the "very shiny ball HTV" in the "beautiful view." The United States astronaut was looking through the windows as she spoke to Houston before she and other flight engineers, Canadian Robert Thirsk and Belgian Frank De Winne, used the station’s robotic arm to grab the spacecraft and attach it to the Earth-facing port of the Harmony node. 

The H-II Transfer Vehicle (HTV), launched by the H-IIB Test Flight Launch Vehicle on September 10, 2009 from the Tanegashima Space Center, was successfully berthed at the International Space Station (ISS) at at 6:26 p.m. EDT on September 18. The ingress is scheduled for 6:30-6:40 p.m. today, a day later.
Planck, a European-US collaborative mission launched by ESA, has provided its first pictures. Planck is a followup to WMAP, and looks at the cosmic microwave background. But it has a host of other detectors and purposes, too. Stealing blatently from Wikipedia, Planck will do:

  1. High resolution detections of both the total intensity and polarization of the primordial CMB anisotropies

  2. Creation of a catalogue of galaxy clusters through the Sunyaev-Zel'dovich effect

  3. Observations of the gravitational lensing of the CMB, as well as the integrated Sachs-Wolfe effect
Black holes are invading stars, according to a new hyposthesis for the origin of the bright flashes in the universe that are one of the biggest mysteries in astronomy today. 

Those flashes, known as gamma ray bursts, are beams of high energy radiation produced by jets of plasma from massive dying stars.   The current model for these cosmic 'jet engines' involves plasma being heated by neutrinos in a disk of matter that forms around a black hole, which is created when a star collapses. 
Meteorites discovered with known orbits are incredibly rare but researchers using cameras which capture fireballs streaking across the night sky have managed to find not only a tiny meteorite on the vast Nullarbor Plain, but also mathematically determine its orbit and the asteroid it came from.

The ability to track meteorites back to their asteroid home also means it is an incredibly cheap way of sampling that asteroid, rather than conducting an expensive space mission.

To find the meteorite, the team deployed three 'all sky cameras' on the Nullarbor Plain to form a fireball camera network.   The cameras take a single time lapse picture of the sky throughout the entire night to record any fireballs over the Plain.