After a one-day delay, NASA's Mars Reconnaissance Orbiter is ready for launch on Thursday, August 11. The first launch window opens from 1150 to 1335 UTC (7:50 to 9:35 am EDT). If the spacecraft fails to launch during this period, there will be additional windows every day through August. It's expected to arrive at Mars in March 2006, where it will perform a series of aerobraking maneuvers for a full half-year before it arrives in its final science orbit.

Our planet gained its nice, oxygen-rich atmosphere about 2.4 billion years ago thanks to early bacteria. One question that has puzzled researchers, however, is why it took at least 300 million years for oxygen to build up to large levels, even though the bacteria had been working madly to produce it. Researchers from the University of Washington have developed a model that shows how volcanic gasses could have sucked up this available oxygen. Not only that, but a large layer of iron from meteorite strikes would have used it for rusting. Not until those sinks were filled could oxygen build up.

The Earth suffered a period of heavy bombardment in its early days when the Solar System was swarming with asteroids. Although it would have been catastrophic for you and I, it might have actually been a nice environment for early microbes. This is according to researchers who spent time at Haughton Impact Crater on Devon Island, in the Canadian Arctic. They found many life-friendly features in this "ground zero", including hydrothermal vents, blasted rocks that make cosy microbe homes, and a nice, protected impact basin.

José Luis Ortiz had no idea that his announcement on July 29th of the discovery of a big Trans-Neptunian Object (TNO) would kickstart one of the most confusing and controversial days for the astronomical community in recent years. The astronomer from Sierra Nevada Observatory, Spain, sent an e-mail detailing his findings with the subject "Big TNO discovery, urgent" to a mailing list for astronomers. A few hours later, reports surfaced on some astronomical websites indicating that the object found by Ortiz, designated as 2003 EL61, was twice as big as Pluto, but they were quickly dismissed by Ortiz.

One person can harvest a field, many people can move a mountain. This is the power of community. The challenge is to get a consensus on the definition of a mountain, which mountain to move, and where to move it. W.D. Kay in his book, Defining NASA - The Historical Debate Over the Agency's Mission uses his skills in political science to look at the United States government's perception of space flight. Though NASA isn't a mountain, it is the result of the contributions of millions of people. Acknowledging this, Kay ponders on what was and what may be for this government agency.

The space shuttle Discovery returned safely back to Earth this morning, landing at Edwards Air Force Base at 1211 UTC (8:11 am EDT). Poor weather over Florida's Cape Canaveral prevented two landing attempts, so managers decided to switch the landing location to California. This safe landing brought mission STS-114 to a successful conclusion, two and half years after the catastrophic destruction of Columbia. The next shuttle, Atlantis, is scheduled to launch September 22, but it all depends on whether they can resolve the foam shedding problems with Discovery's launch.

Brad Timerson took this picture of the Moon and Venus on August 7, 2005. Brad used Olympus C740 camera at 10x zoom with 1/30th second exposure.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Astrophotographer John Chumack with DIRAS Observatory Team took this picture of the newly discovered 10th Planet with 8 minute exposure on the 31st Jul. and 10 minute exposure on 1st Aug. John used a 0.30 meter FL. 11.9 Takahashi Dall-Kirkham Scope and Software Bisque ParaMount and FLI CCD.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Greetings fellow SkyWatchers! The week starts off rather special as observers in Alaska get the opportunity to watch the Moon occult Venus and more. The return of the Moon might mean the loss of early evening deep sky studies, but we'll still enjoy lunar features and the timeless dance of its orbital track. Take advantage of every clear night as the Perseid meteor shower gears up for its annual peak on Thursday. Keep your eyes on the skies, because...

Here's what's up!

The Mars Exploration Rovers have unquestionably been one of NASA's most exciting and successful missions to date. The projects scientific principal investigator, Dr. Steve Squyres of Cornell University has written a candid and fascinating new book about the mission. Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet offers an inside look at the journeys the rovers have taken; not only their captivating treks across Mars, but the surprisingly circuitous and difficult route they took from inception to development and launch.

If humans are going to live on Mars, we're going to need to learn how to grow plants in the planet's thin atmosphere, poor soil, severe cold, and total lack of water. This environment will put plants into a severe state of stress and shut down their metabolism, but NASA scientists think they've got strategies to help them cope. By introducing genes from extremophile microbes that can withstand severe changes in environment, scientists are hoping to modify plants so they won't shut down their metabolism in response to stress.

The space shuttle Discovery's landing has been pushed back to Tuesday because of low clouds above Florida's Cape Canaveral on Monday. All three primary landing sites will be activated on Tuesday, so the shuttle can potentially land at Cape Canaveral, Edwards Air Force Base in California, or White Sands Space Harbor in New Mexico. Weather forecasters are expecting similar weather in Florida for Tuesday, so it's likely Discovery will have to use an alternative site. The first landing attempt will be at 0907 UTC (5:07 am EDT).

NASA's Mars Reconnaissance Orbiter (MRO) is set to launch in just a couple of days - its launch window opens up on Wednesday, August 10 at 1153 UTC (7:53 am EDT). If all goes well, the spacecraft will blast off on top of an Atlas V-401 rocket with Russian-made RD-180 engines. When it finally reaches Mars in a few months, MRO will begin a series of 514 aerobraking maneuvers, where it skims through the top of the atmosphere to slow down its velocity and bring it into its final science orbit.

During its recent flyby of Mimas, Cassini found the Saturnian moon to be heavily battered and bruised by impact craters; it's the most heavily bombarded of Saturn's moons. It also got a perfect image of Mimas' Hershel crater, which is 140 km (87 miles) across, and makes the moon look like the Death Star. By analyzing the impact craters, scientists hope to calculate how many impacting asteroids moved through the region early in the life of our Solar System.

Earth isn't the only place that gets the Northern and Southern Lights, or auroras. NASA's Cassini spacecraft has taken an ultraviolet image of Saturn that shows its southern pole covered by an aurora. In this false-colour image, the blue indicates the aurora emissions created by hydrogen gas excited by electron bombardment, and the red-orange is reflected sunlight. Another photo, taken just an hour later shows how quickly these auroras are changing.

The MARSIS radar instrument on board Mars Express is now extended and fully operational, and ESA scientists have begun using it to probe beneath the surface of Mars in search of water and ice. During this initial commissioning phase, operators have used the instrument to examine Mars' topography to compare its reading against previous readings of the Red Planet to make sure its calibrated correctly. Within a few weeks they'll start isolating areas where the radar is penetrating beneath the surface to start mapping out underground layers.

Skywatchers in the Southeastern United States will have an opportunity to watch the International Space Station and the space shuttle Discovery fly overhead on Saturday morning at 5:50 am CDT.. Discovery will have undocked from the station three hours previously, so the two objects will be separated visually by about the width of the Moon. As a special bonus, the two spacecraft will pass close to the planet Mars as well.

NASA astronauts on board Discovery and the International Space Station held a tribute to remember the crew of Columbia, which was destroyed during its re-entry more than two years ago. Each crewmember wore a red shirt with Columbia's STS-107 mission patch, and spoke, paying their respects to the crew of STS-107, as well as Challenger, Apollo 1, Soyuz 1 and 11.

NASA has given the space shuttle Discovery a green light to return to Earth on Monday, August 8th. The agency's Mission Management Team has decided that the shuttle's heat shield and other systems are in good shape, after Wednesday's spacewalk to remove excess gap filler between shuttle tiles. The team also decided that a torn thermal blanket won't be a risk as the shuttle re-enters the atmosphere.

At least three massive asteroids smashed into the Earth more than 3.2 billion years ago, and caused such destruction, they dramatically changed the structure and composition of the Earth's surface. This is according to new research from scientists at the Australian National University. The team uncovered evidence of major earthquakes, faulting, and volcanic eruptions that were so violent they dramatically changed the way the Earth's surface was forming. This happened during a period that the Moon also suffered heavy bombardment.